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31 publications mentioning dme-mir-7

Open access articles that are associated with the species Drosophila melanogaster and mention the gene name mir-7. Click the [+] symbols to view sentences that include the gene name, or the word cloud on the right for a summary.

1
[+] score: 388
Other miRNAs from this paper: hsa-mir-7-1, hsa-mir-7-2, hsa-mir-7-3
Conversely, while the target genes of the Notch pathway, E(spl)m3 and E(spl)m4 [48] as well as E(spl)mγ, Bob, E(spl)m5, and E(spl)mδ [60], have been identified as direct targets of miR-7 in the normal wing disc via analysis of 3′UTR sensors, there was no evidence that HLHm3, HLHm4, HLHm5, Bob, and HLHmγ are biological relevant targets of miR-7 in the Dl overexpression context. [score:10]
We hypothesized that mir-7 overexpression would be mimicked by endogenous downregulation of the functional relevant target gene(s) in the context of Dl overexpression. [score:10]
Thus, specific down-regulation of endogenous ihog, a predicted target of miR-7, facilitates overgrowth by Dl overexpression similar to those that develop when mir-7 is overexpressed in this context (Figure 1, Figure 2, and Figure S4H). [score:10]
The advanced MF is seen in ey>Dl eye discs with downregulation of Hh signalling via overexpression of mir-7 or direct downregulation via RNAi transgenes (Figures S3 and S4). [score:10]
In conclusion, we have identified cooperation between the microRNA miR-7 and Notch in the D. melanogaster eye and identified and validated ihog as a direct target of the miR-7 in this context and have identified boi as a target of Notch -mediated activity at the DV eye organizer, although it remains whether this regulation is direct or indirect. [score:9]
Indeed, of the 39 predicted miR-7 target genes tested by direct RNAi, only downregulating ihog with several RNAi transgenes (UAS-ihog-IR) fully mimicked the effect of miR-7 overexpression in the transformation of Dl -induced mild overgrowth into severe overgrowth and even tumour-like growth. [score:9]
However, since miR-7 only very subtly reduces the expression of endogenous hairy and a GFP-3′UTR hairy sensor [48], we focused our interest on the gene, interference hedgehog (ihog), that when downregulated in Dl -overexpressing cells provoked robust overgrowth (Figure 2, Figure S4E–F,H, and Table S1). [score:8]
Nevertheless, the qRT-PCR comparisons between the different genotypes showed a trend in boi and ihog expression response to Dl overexpression that explains the cooperation between the miR-7 and Dl signalling, since there is the concomitant downregulation of the two functionally redundant Hh receptor genes, ihog and boi. [score:8]
The downregulation of smo (80% flies exhibited eye tumour-like growth, n >200), ci (100%, n>200), or hh (30%–100%, n>200) in conjunction with Dl overexpression provoked a tumour phenotype similar to that of RNAi of ihog but stronger than the overexpression of mir-7 (compare Figure 1 and Figure 2 with Figure 4B–D; see also Table S2). [score:8]
Identification of Candidate Tumour Suppressor Targets of miR-7 by in Vivo RNAi Screening in the Delta Overexpression Mo del. [score:7]
Figure S6Overexpression of DsRed::mir-7 by en-Gal4 in the wing disc also caused reproducible in vivo downregulation of eGFP in a tub-eGFP::ihog-3′UTR (A) but not in a tub-eGFP::boi-3′UTR sensor (B). [score:6]
However, downregulation of Notch signalling alone might not explain the synergism between mir-7 and Dl overexpression in eye overgrowth as we did not detect reduction of the organizing signalling by Dl-Notch in these discs (Figure S3). [score:6]
Note that the smo [3]/smo [3]tub-Gal4 UAS-Dl clones cause nonautonomously advancement of the MF denoted by up-regulated Ci levels, similar to the effect seen in eye discs co -expressing Dl with the mir-7. (A′) and (B′) show single channel confocal images. [score:6]
We used RNA interference (RNAi) UAS -driven transgenes (UAS-IR) to downregulate candidate and previously validated miR-7 target genes in vivo. [score:6]
Although not previously characterized as a target gene of miR-7, the downregulation of ihog by RNAi concomitant with the gain of Dl function consistently produced enlarged eye discs (Figure S4E–F) similar to that in eye discs co -expressing Dl and mir-7 (Figure S3I–J), resulting in adults with overgrown and folded eyes (ey>Dl>ihog-IR: 80% of severe overgrown eyes, n = 200; Figure 2B and Table S1). [score:6]
In addition to the direct regulation of the ihog mRNA 3′UTR by miR-7 in vitro, there was specific in vivo repression of the tub-luc::ihog-3′UTR construct but not the ihog 3′UTR construct that carried the mutations in the seed sequence (Figure 2FG) and of an ihog 3′UTR eGFP sensor (tub-eGFP::ihog-3′UTR) but not a similar boi 3′UTR eGFP sensor (tub-eGFP::boi-3′UTR) (Figure S6AB) in the posterior compartment cells of third instar wing discs overexpressing mir-7 driven by engrailed (en) -Gal4. [score:6]
brother of ihog Is Negatively Regulated by Notch Signalling during Eye GrowthAlthough boi mRNA expression was not affected in the ihog-IR lines and Boi does not appear to be a target of miR-7, there is a well-documented functional overlap in the roles of Ihog and Boi. [score:6]
The weak downregulation of Ci by mild RNAi expression using ptc-Gal4 mimicked the L3–L4 fusion defect of ptc>mir7 (Figure 6C–D). [score:6]
In human cancer cells, miR-7 has been postulated to have an oncogene [89], [90] or a tumour suppressor functions [91]– [96] that may reflect the participation of the microRNA in distinct pathways, due to the regulation of discrete target genes in different cell types, such as Fos [97] in mouse, and Pak1 [91], IRS-2 [92], EGFR [92], [93], Raf-1 [93], α -synuclein [98], CD98 [99], IGFR1 [94], bcl-2 [100], PI3K/AKT [101], [102], and YY1 [103] in humans. [score:6]
However, although it remains to be shown whether similar interactions are active during cell proliferation and growth, the moderate enhancement of Dl that is induced when Tom is downregulated by RNAi suggests that miR-7 -mediated repression of Tom may contribute to the oncogenic effects of miR-7 in the context of Dl gain of function, along with other targets such as ihog. [score:6]
Importantly, both boi and ihog mRNA levels were downregulated in eye discs that co-expressed Dl with the microRNA mir-7 (ey>Dl>mir-7; Figure 3J). [score:6]
In addition, by identifying and validating functionally relevant targets of miR-7 in tumourigenesis, we also exposed a hitherto unsuspected tumour suppressor role for the Hh signalling pathway in the context of the oncogenic Notch pathway. [score:5]
Indeed, expressing GS(2)518ND2 along the AP compartment boundary in the wing imaginal disc using patched (ptc) -Gal4 caused similar L3-–L4 fusion as that reported following mir-7 overexpression in this domain (ptc>GS(2)518; Figure 1G). [score:5]
Validation of Interference Hedgehog as a Direct Target of miR-7 in Vitro and in VivoSince the ihog gene encodes a receptor of Hh in the embryo, including the imaginal eye disc [30], we assessed whether it is directly regulated by miR-7 in luciferase reporter -based cellular assays in vitro and in vivo (Figure 2). [score:5]
Although boi mRNA expression was not affected in the ihog-IR lines and Boi does not appear to be a target of miR-7, there is a well-documented functional overlap in the roles of Ihog and Boi. [score:5]
We tested candidate target genes predicted by several algorithms ([52]; see ) and that contain the conserved Drosophila miR-7 binding sites, which normally reduces the number of false positive target predictions. [score:5]
Table S1Identification of candidate tumour-suppressor gene(s) of Drosophila in silico predicted miR-7 target genes in the gain of Dl context. [score:5]
Although it has been postulated that the microRNA mir-7 silences Notch signalling, the overexpression of mir-7 with Dl causes eye disc overgrowth associated with enhanced Dl-Notch signalling as detected by the misexpression of DV organizer-specific markers (F and H). [score:5]
Thus, the Ci low protein levels in ptc>mir-7 wing discs could reflect the direct repression of ci by the microRNA or the dampening of Hh signalling response by the miR-7 -mediated downregulation of ihog or both. [score:5]
We also did not obtain evidence that miR-7 provoked overgrowth by targeting the ETS transcription factor in the EGFR pathway AOP/Yan (Table S1), a functionally validated target of the microRNA miR-7 during retinal differentiation [47]. [score:5]
As expected, co -expressing Dl with the RNAi against ihog or ci with ey-Gal4 provoked overgrowth similar, but stronger than the misexpression of the mir-7. Anterior is to the left in all images, and dorsal is up. [score:5]
Note that when Ci full length is expressed in the context of Dl and mir-7 overexpression, although many eyes are substantially reduced in size they still exhibit abnormal patterned growth (see Figure 4L) and other exhibited enhanced tumorigenesis. [score:5]
Thus, expression differences between the control and Dl and/or mir-7 overexpressing eye-antennal disc complexes may be significant underestimations of the actual differences in the relevant eye disc part in each genotype. [score:5]
To identify the former, we considered that a bona fide miR-7 target gene would not produce any effect when downregulated in the context of normal Notch signalling. [score:5]
More consistently with indirect regulation of Ci by miR-7, we observed no change in Ci protein levels in wing discs ectopically expressing the mir-7 away from the normal Hh secreting cells (the P compartment cells marked by the absence of Ci (green) in Figure 6G). [score:5]
In addition, luciferase activity was unaffected by mir-7 overexpression in a control tub-luc::boi-3′UTR construct, indicative that the functional similar boi was not a target of miR-7 (Figure 2E). [score:5]
Confocal images of eye discs of control wild type (ey>, A, C, E, and G) and eye discs overexpressing Dl and mir-7 by ey-Gal4 (ey>Dl>GS(2)518: B, D, F, H–J) and carrying the indicated enhancer trap lines to monitor DV patterning: expression of D marker mirror-lacZ (mirr-Z), ventral marker fringe-lacZ (fng-Z), DV organizer-specific marker Serrate-lacZ (Ser-Z), and eyegone-lacZ (Eq-Z). [score:5]
Since human RAS regulates tumourigenesis in the lung by overexpressing miR-7 in an ERK -dependent manner [90], it is possible that RAS represses CDO and BOC via this microRNA. [score:4]
We identified the ihog gene as a functionally relevant, direct target of miR-7 in Notch -mediated tumourigenesis in vivo. [score:4]
Validation of Interference Hedgehog as a Direct Target of miR-7 in Vitro and in Vivo. [score:4]
Conversely, the direct overexpression of mir-7 together with Dl (hereafter, ey>Dl>mir-7), using a mir-7 transgene that does not contain any bl sequences (UAS-mir-7), provoked overgrown larval eye discs ey>Dl>mir-7 (Figure 1H; compare with sibling wild type eye discs, Figure 1I) associated with significant increased cell proliferation (Figure 1J and Figure S4C–D,H), resulting in adult overgrown and folded eyes similar to that in the GS(2)518ND2 flies (70% of adult ey>Dl>mir-7 animals displayed eye benign tumour-like growth, n = 200; Figure 1K and Figure S2A–C). [score:4]
Hence, the downregulation of ihog/boi levels by Dl/miR-7 (see Figure 3J) might reduce the interactions of Hh with Ptc. [score:4]
Indeed, we observed a clear downregulation of Ci protein levels in cells in ptc>mir-7 (Figure 6A–B″), which are precisely the cells receiving endogenous Hh signals and that upon normal Hh reception stabilize Ci protein levels and prevent the conversion of Ci-155 into truncated Ci repressor. [score:4]
These results raised the possibility that like ihog, ci is also a direct target of miR-7. Indeed, c i mRNA does contain a presumptive miR-7 binding site in the ci 3′UTR, although this site is not conserved across Drosophila species. [score:4]
Finally, we demonstrated that endogenous ihog mRNA was inhibited by miR-7 in vivo as heat shock induction of mature mir-7 overexpression (hsp70-Gal4 UAS-mir-7) provoked a 55% reduction in ihog mRNA transcripts in larvae when assayed by qRT-PCR (Figure 2H and Figure S2D). [score:4]
Therefore, either Ci is not a target of miR-7 or this regulation is context dependent. [score:4]
Further, we provide evidence that the microRNA mir-7 and Notch pathway cooperatively dampen Hh signal transduction via down-regulation of its receptors ihog and boi, respectively. [score:4]
The co -expression of UAS-mir-7 with UAS-Dl causes eye disc overgrowth and a front of retinal differentiation highly disorganized (H, compare with control sibling eye disc in I). [score:3]
In Drosophila, multiple, cell-specific, targets for miR-7 have been previously validated via luciferase or in vivo eGFP-reporter sensors or less extensively via functional studies [47], [49], [73], [104]– [107]. [score:3]
Previously, misexpression of mir-7 driven by ptc-Gal4 (ptc>mir-7) produces wing margin notches, and a reduction of the space between vein L3 and L4 ([48]; see [72]). [score:3]
Depleting ihog by RNAi driven by ptc-Gal4 did not produce a defect as mir-7 overexpression (Figure 6E). [score:3]
Larvae carrying both the chromosomes with the transgenes ey-Gal4 UAS-Dl (2nd) and UAS-DsRed::mir-7 (3rd) were selected under a fluorescence binocular (MZFLIII, Leica) for expression of DsRed in the eye under the control of Gal4. [score:3]
In the wing disc, the miR-7 microRNA is thought to silence target genes of the Notch pathway [47], [48]. [score:3]
Nevertheless, other miR-7 target genes may contribute to the cooperation with Dl-Notch pathway along with ihog, such as hairy and Tom. [score:3]
MicroRNA miR-7 Cooperates with Delta to Trigger Severe Overgrowth in Drosophila EyeTo identify endogenous genetic determinants that may limit Notch -driven tumourigenesis in vivo, we carried out an unbiased (genome-wide) gain-of -expression screen for loci that converted Dl -induced mild eye overgrowth into severe overgrowths (benign tumour-like growth: eye tissue is overgrown and folded) or metastatic tumours (provoke secondary eye growths throughout the body). [score:3]
We asked whether our identification of ihog as a key target of miR-7 during Dl -mediated tumorigenesis in the eye might reflect endogenous roles of the microRNA in other tissues. [score:3]
There is a single conserved miR-7 binding site in the 3′UTR of ihog (Figure 2D) and in Drosophila Schneider (S2) cells overexpressing mir-7, there was 45% less activity of a luciferase reporter containing the full-length ihog 3′ UTR downstream of the firefly luciferase coding region driven by the α-tubulin promoter (tub-luc::ihog-3′UTR Figure 2E and Figure S5C). [score:3]
The undifferentiated outgrowths are seen also in flies co -expressing Dl with the UAS-mir-7 transgene (B and C). [score:3]
Figure S4Overgrowth and abnormal neuronal differentiation progression in eye discs co -expressing Dl and the microRNA mir-7 or the ihog-IR or ci-IR transgenes. [score:3]
There was no increase in eye size when UAS-mir-7 alone was overexpressed by ey-Gal4 (ey>mir-7; Figure 1L). [score:3]
A set of EP elements in the vicinity of GS(2)518ND2 has been previously described to cause mir-7 overexpression, and to induce proximal fusion of longitudinal (L) veins 3 and 4, as well as distal wing notching or bristle tufting [45]– [47]. [score:3]
boi and ihog RNA was isolated from whole eye-antennal disc complexes; thus, the mRNA levels are the sum of all regions of the discs, including the antenna, which is not affected by ey>Dl or ey>mir-7. Hence expression differences with control may be significant underestimations of the actual differences of each gene in the eye disc parts in the different genotypes. [score:3]
Moreover, we confirmed that endogenous ihog is directly silenced by miR-7 and that this silencing involves direct binding of the microRNA to sequences in the 3′UTR of ihog both in vivo and in vitro. [score:3]
Loss of Hedgehog Signalling in miR-7 Overexpression in the Wing. [score:3]
A previously validated target of miR-7, hairy [48] was capable of converting Dl -induced mild overgrowth into tumour-like growth (Table S1). [score:3]
Therefore, we sought to identify miR-7 target gene(s) that might be relevant to the cooperation with Dl-Notch signalling in eye overgrowth and tumourigenesis. [score:3]
A boi transgene (UAS-boi) [56] fully suppressed the overgrowth induced by the combination of mir-7/Dl (Figure 3K, 100% penetrance, n = 100). [score:3]
As such, we systematically assayed a set of 39 D. melanogaster genes predicted to be miR-7 targets in silico (Table S1, [49]). [score:2]
While miR-7 can directly silence hairy in the wing, this effect has been shown to be very modest [48], and thus, we consider that while hairy may contribute to such effects, it is unlikely to be instrumental in this tumour mo del. [score:2]
1001554.g002 Figure 2Tumourigenesis promoted by miR-7 via direct repression of interference hedgehog (ihog). [score:2]
Overall, these data provide convincing evidence that miR-7 is capable of directly repressing ihog, both in vitro and in vivo. [score:2]
The assay would not, however, distinguish between a bona fide miR-7 target gene and those genes that are required normally for restricting tissue growth. [score:2]
Given the conservation of the Notch and Hh pathways, and the recurrent alteration of microRNAs in human cancers, we speculate that the genetic configuration of miR-7, Notch, and Hh is likely to participate in the development of certain human tumours. [score:2]
Thus, the relevance of co-regulation of ihog and ci by miR-7 in Hh receiving cells deserves further analysis given that the human counterparts of these genes (CDO, BOC, and Gli3) also contain binding sites for human miR-7. 10.1371/journal. [score:2]
Tumourigenesis promoted by miR-7 via direct repression of interference hedgehog (ihog). [score:2]
To construct the tub-luc::ihog [mut]3′UTR reporter, three nucleotides of the predicted binding site for miR-7 in the ihog 3′UTR were mutated (AGTCTTCCA to AGTC AT GC T) using the QuickChange Site-Directed Mutagenesis kit (Agilent Technologies Inc. [score:2]
Since the ihog gene encodes a receptor of Hh in the embryo, including the imaginal eye disc [30], we assessed whether it is directly regulated by miR-7 in luciferase reporter -based cellular assays in vitro and in vivo (Figure 2). [score:2]
Thus, the relevance of co-regulation of ihog and ci by miR-7 in Hh receiving cells deserves further analysis given that the human counterparts of these genes (CDO, BOC, and Gli3) also contain binding sites for human miR-7. 10.1371/journal. [score:2]
By contrast, when the ihog 3′UTR construct carried point mutations in the miR-7 binding site (tub-luc::ihog(mut)-3′UTR), luciferase activity was the same as in control cells (Figure 2E). [score:2]
To assess the levels of ihog or boi mRNA when the mir-7 or RNAi lines were activated by Gal4, we performed qRT-PCR experiments using RNA isolated from wandering third instar larvae of the hsp70-Gal4 genotype crossed with transgenic lines (UAS-mir-7, UAS-ihog-IR, or UAS-boi-IR) directly or following heat shock (an hour at 37°C followed by 6 h at 25°C). [score:2]
Here, we describe the identification of the conserved microRNA (miRNA) miR-7 as a gene that enhances Notch pathway -induced eye overgrowth in D. melanogaster. [score:1]
Increasing Hedgehog Signal Prevents Tumourigenesis by Delta and miR-7. Hedgehog Signal Transduction Also Attenuates Delta Signalling and Overgrowth in the Wing. [score:1]
To analyse mature mir-7 expression, we used mir-7-specific primers from the TaqMan MicroRNA Assays (Applied Biosystems), together with the TaqMan MicroRNA Reverse Transcription Kit (Applied Biosystems) and TaqMan Universal PCR Master Mix (Applied Biosystems). [score:1]
Thus, the synergism between miR-7 and the Dl-Notch pathway activity in eye overgrowth would appear to be largely due to the silencing of ihog. [score:1]
Given the conservation of miR-7, as well as of the Notch and Hedgehog pathways, the conclusions we have drawn from these studies on Drosophila may be applicable to some human cancers. [score:1]
C. Klambt (Munster University, Munster, Germany), and the other Drosophila stocks used here were: UAS-mir-7 and UAS-DsRed::mir-7 [47], UAS-boi [56], UAS-ci [57], and UAS-ci-75 [58], [59]. [score:1]
Plots of fluorescence intensity profiles of the anterior-posterior compartments from the WT (A) and ptc>DsRed::mir-7 (B′) discs are shown in (A′) and (B″), respectively. [score:1]
Plots of fluorescence intensity profiles from the wild-type and ptc>mir-7 discs are shown in Figure 6A′ and B″. [score:1]
We therefore investigated whether increasing Hh signal via a UAS-hh transgene to counterbalance ihog/boi deficit could rescue the overgrowth by Dl/ mir-7. Indeed, we detected significant reduction in eye size in flies ey>Dl>mir-7>hh (Figure 4K; 100% rescue, n>100; see Figure S9 for scheme of genetic test for rescuing experiment) and also in flies that expressed Ci full length (ey>Dl>mir-7>ci; Figure 4L). [score:1]
Confocal images of mitotic marker PH3 (blue in A–E; pink in F and green in G), neuronal marker Elav (green, A–F and red in G), and Wg (red, A–D and pink in F) staining of third instar eye-antennal imaginal discs of wild-type ey-Gal4 (ey>, A–A′), ey-Gal4 UAS-Dl (ey>Dl, B–B′), ey-Gal4 UAS-Dl/+; UAS-mir-7/+ (ey>Dl>mir-7, C–D′), ey-Gal4UAS-Dl/+; UAS-ihog-IR/+ (ey>Dl>ihog-IR, E–F), and ey-Gal4 UAS-Dl/+; UAS-ci-IR/+ (ey>Dl>ci-IR, G). [score:1]
In this experiment, we used the Beadex (Bx) -Gal4 driver, with the Bx domain labelled by DsRed because of the UAS-DsRed::mir-7 transgene (Figure 6G). [score:1]
We interpret these findings as Ci full length can be converted into the repressor form owing to the reduced Hh signalling caused by Dl and miR-7 depletion of ihog and boi. [score:1]
Indeed, the 3′UTR of both CDO and BOC like Drosophila ihog contains predicted binding sites for miR-7 (www. [score:1]
Figure S5Quantification of ihog and boi mRNAs and mature mir-7 levels. [score:1]
The mir-7 levels were normalized to U14 snRNA. [score:1]
Female virgin w; ey-Gal4 UAS-Dl/Cy0-GFP were crossed to males w; +/+; UAS-DsRed::mir-7 and their F1 progeny larvae (w; ey-Gal4, UAS-Dl/+; UAS-DsRed::mir-7/+) were selected by DsRed labelling in the pair of eye-antennal discs. [score:1]
By studying how Delta-Notch signalling drives tumorigenesis, we identified the conserved microRNA miR-7 as a co-operative element in tumorigenesis mediated by Delta. [score:1]
1001554.g001 Figure 1The Conserved MicroRNA miR-7 co-operates with Notch in D. melanogaster oncogenesis. [score:1]
Like the mir-7 and ihog-IR lines (Figure 1L and Figure 2C), none of the above RNAi lines were capable of inducing overgrowth by themselves. [score:1]
The Conserved MicroRNA miR-7 co-operates with Notch in D. melanogaster oncogenesis. [score:1]
All tissue samples were stored in RNAlaterTissueProtect Tubes (Qiagen) until used and mature mir-7, ihog, or boi mRNA levels were assessed by qRT-PCR. [score:1]
Figure S2The conserved MicroRNA miR-7 and Dl-Notch pathway cooperatively induce eye overgrowth. [score:1]
The GS(2)518ND2 line carried an insertion 3.1 kb upstream of the mir-7 miRNA gene (Figure 1F), which is transcribed from an internal promoter within a 3′ intron of the bancal/ heterogeneous nuclear ribonucleoprotein K (bl/hnRNP-K) gene [45]. [score:1]
MicroRNA miR-7 Cooperates with Delta to Trigger Severe Overgrowth in Drosophila Eye. [score:1]
In this sense, we describe here a conserved microRNA that cooperates with Notch -induced overproliferation and tumour-like overgrowth in the D. melanogaster eye, miR-7. Alterations in microRNAs have been implicated in the initiation or progression of human cancers (e. g., [80]– [84]), although such roles of microRNAs have rarely been demonstrated in vivo (e. g., [85]– [88]). [score:1]
miR-7 silencing of Hh signalling explains the L3–L4 fusion defects in the wing. [score:1]
Surprisingly, we could not overcome overgrowth by mir-7/Dl using this transgene (unpublished data). [score:1]
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Figure 3 miR-7 Targets Members of the E(spl) Complex at the Transition Zone(A and A’) In (A), clonal expression of UAS- miR-7 marked by UAS-myr-tdTomato (red) is able to downregulate E(spl)m-gamma-GFP. [score:8]
Examination of the miR-7 enhancer driving GFP ((miR-7)E-GFP) (Li et al., 2009), revealed expression in the transition zone that overlapped precisely L’sc expression (Figures 1D and 1D′), suggesting that miR-7 is upregulated in the transition zone. [score:8]
Misexpression of miR-7 results in an increase in Ato expression and R8 cell specification, while a loss of miR-7 results in a decrease in Ato expression under conditions of temperature stress. [score:7]
mir-7 Is Expressed at the Transition Zone in the Optic LobePreviously we used Targeted DamID to profile gene expression in neuroepithelial cells and neuroblasts of the developing larval optic lobe (Southall et al., 2013). [score:7]
We reasoned that, in the absence of miR-7, the levels of its target gene(s) should increase and that this increase could be suppressed by reducing the gene dose of the target gene(s). [score:7]
Misexpression of miR-7 in neuroepithelial cells resulted in disruption of the neuroepithelium and ectopic neuroblast formation (Figures 2A and 2B), similar to what was seen when Notch activity was downregulated throughout the neuroepithelium (Egger et al., 2010). [score:6]
Similar to the expression of (miR-7)E-GFP in the eye imaginal disc (Li et al., 2009), expression of hnRNP-K/miR-7 in the optic lobe was positively regulated by EGF signaling (Figure S1). [score:6]
To determine which predicted targets miR-7 regulates at the transition zone, we performed genetic suppression experiments. [score:6]
Expression of UAS- miR-7 in clones was able to autonomously downregulate E(spl)m-gamma-GFP at the transition zone (Figures 3A and 3A′). [score:6]
This highly specific upregulation of hnRNP-K/miR-7 transcript at the transition zone suggested a role in regulation of the transition of neuroepithelial cells to neuroblasts. [score:5]
The ability of miR-7 to regulate Notch signaling was of interest, as Notch signaling is known to be essential to maintain neuroepithelial cells, and downregulation of Notch activity is required for transition to neuroblasts (Egger et al., 2010, Ngo et al., 2010, Orihara-Ono et al., 2011, Wang et al., 2011, Yasugi et al., 2010). [score:5]
One of these, E(spl)m-gamma, is known to be expressed in the neuroepithelium (Egger et al., 2011), intriguingly, in a pattern reciprocal to that of hnRNP-K/miR-7 expression (Figure 1E′). [score:5]
This raises the possibility that miR-7 targeting of aop could also contribute to its function in buffering the neuroepithelial-to-neuroblast transition and that aop could represent a common target during the progression of the proneural wave and the morphogenetic furrow. [score:5]
To assess more precisely the effects of miR-7 misexpression, we generated clones of cells expressing miR-7. Clones that spanned the transition zone showed premature neuroblast formation (Figures 2C–2C″). [score:5]
miR-7 promotes neuroblast formation during optic lobe developmentmiR-7 targets the Notch pathway • miR-7 buffers the effects of environmental stress •Without miR-7, timely neuroblast production is disrupted neural stem cell neuroepithelium neuroblast optic lobe microRNA Drosophila miR-7 transition zone proneural wave canalization Drosophila vision requires the accurate specification of over 80 different types of optic lobe neurons and the establishment of precise visual circuits between the neurons of the optic lobe and the photoreceptors of the eye. [score:4]
We observed a band of increased hnRNP-K/miR-7 transcription that overlaps the transition zone, marked by the downregulation of E(spl)m-gamma-GFP (Almeida and Bray, 2005, Egger et al., 2011). [score:4]
miR-7, expressed in a pattern similar to that of l’sc at the transition zone, provides another, emphasizing the importance of Notch regulation at the transition zone. [score:4]
This shows that deregulation of targets within the E(spl)-complex is responsible for the observed defect in proneural wave co-ordination seen in miR-7 [CRISPR1] mutants. [score:4]
Although expression of miR-7 was sufficient to promote the neuroepithelial-to-neuroblast transition, we only observed a delay in transition in 30% of miR-7 [CRISPR1] mutant clones (Figures 2E–2E″), suggesting that transition can occur correctly in the absence of miR-7 and that only under certain circumstances does the loss of miR-7 affect timely neuroblast production. [score:3]
miR-7 Targets E(spl)m-gamma at the Transition ZonePredicted miR-7 binding sites can be found in the 3′ UTRs of many genes encoding downstream effectors and modulators of Notch pathway activity, including members of the Enhancer of split complex (E[spl]-C) and Bearded complex (Brd-C) (Kheradpour et al., 2007, Lai et al., 2005, Robins et al., 2005, Ruby et al., 2007). [score:3]
miR-7 is predicted to target multiple members of the Notch pathway. [score:3]
We showed that miR-7 promotes neuroepithelial cell-to-neuroblast transition by targeting downstream Notch effectors to limit Notch signaling. [score:3]
We confirmed this expression pattern using single-molecule fluorescence in situ hybridization (FISH) (smFISH) against the hnRNP-K/miR-7 transcript (Figures 1E and 1E′). [score:3]
We discovered that microRNA miR-7 is expressed at the transition between neuroepithelial cells and neuroblasts. [score:3]
We found that hnRNP-K/ miR-7 expression was enriched in neuroepithelial cells (Figure 1C). [score:3]
mir-7 Buffers the Neuroepithelial-Cell-to-Neuroblast TransitionAlthough expression of miR-7 was sufficient to promote the neuroepithelial-to-neuroblast transition, we only observed a delay in transition in 30% of miR-7 [CRISPR1] mutant clones (Figures 2E–2E″), suggesting that transition can occur correctly in the absence of miR-7 and that only under certain circumstances does the loss of miR-7 affect timely neuroblast production. [score:3]
miR-7 has been shown to target anterior open (aop; also known as yan) in the eye imaginal disc (Li and Carthew, 2005). [score:3]
miR-7 Targets E(spl)m-gamma at the Transition Zone. [score:3]
We examined proneural wave progression in the absence of miR-7 in a background heterozygous for deficiencies that delete large parts of either the E(spl) or the Brd complex, each removing several predicted miR-7 targets (Figure 4D) (Chanet et al., 2009). [score:3]
We have shown here that miR-7 targets members of the E(spl) family of bHLH transcription factors to define the boundaries of the transition zone, buffering the transition from neuroepithelial cell to neuroblast in the developing optic lobe. [score:3]
To examine whether miR-7 targets E(spl)m-gamma in vivo, we took advantage of the E(spl)m-gamma-GFP reporter, a genomic fragment containing GFP cloned in frame, 19 amino acids (aas) from the end of E(spl)m-gamma (Almeida and Bray, 2005). [score:3]
miR-7 is predicted to target a number of other basic-helix-loop-helix (bHLH) transcription factors and Brd genes of the E(spl) complex and Brd complex (Kheradpour et al., 2007, Lai et al., 2005, Ruby et al., 2007). [score:3]
Together, these results confirm that E(spl)m-gamma is a target of miR-7 at the transition zone and that miR-7 represses a downstream effector of Notch signaling at the transition zone. [score:3]
We present evidence here that the transition from neuroepithelial cells to neuroblasts in the developing optic lobe is buffered by the microRNA miR-7. miR-7 is expressed at the transition zone in response to epidermal growth factor (EGF) signaling and is sufficient to promote transition. [score:3]
Predicted targets of miR-7 are indicated with an asterisk. [score:3]
Figure 2 miR-7 Is Sufficient to Promote Premature Transition and Is Necessary for Robust and Timely Transition (A) Wild-type optic lobe showing expression of L’sc (blue) and Dpn (red). [score:3]
mir-7 Is Expressed at the Transition Zone in the Optic Lobe. [score:3]
These results show that miR-7 plays a role in regulating the timing of the proneural wave and suggest that it may act by negatively regulating Notch signaling. [score:3]
These results show that miR-7 acts to buffer the development of both the medulla and the eye, two tissues that will directly communicate in the adult brain. [score:3]
Flies expressing the miR-7 gRNA were crossed to a nos-cas-9 line. [score:3]
This vector was injected into nos-phiC integrase; +; attP2 embryos to generate a stable line expressing the miR-7 gRNA under control of the U6:3 promoter. [score:3]
Figure 1 miR-7 Is Expressed in the Transition Zone of the Developing Optic Lobe (A) Cartoon of a lateral view of the larval brain. [score:3]
While loss of one copy of Df(3)Brd-C1 did not change the severity of proneural wave disruption relative to loss of miR-7 alone (p = 0.50, Fisher’s exact test) (Figures 4C and 4H), loss of one copy of the Df(3)E(spl) delta-6 was able to suppress the proneural wave disruption observed in miR-7 [CRISPR1] mutant brains under temperature stress (p = 0.002, Fisher’s exact test) (Figures 4C and 4G). [score:3]
Figure 4 miR-7 Buffers Transition through Regulation of the E(spl) Complex (A) The transition zone labeled with L’sc in a control (w1118; +; +) third-instar larval optic lobe. [score:2]
The presence of miR-7 in both the eye imaginal disc and the optic lobe represents an independent but conserved buffer that operates to coordinate appropriate developmental progression in each system, in spite of external environmental fluctuations. [score:2]
Therefore, regulation of members of the E(spl) complex by miR-7 is necessary for buffering the transition from neuroepithelial cells to neuroblasts against environmental stress. [score:2]
We hypothesized that miR-7 plays a role in regulating Notch activity at the transition zone. [score:2]
mir-7 Regulates Notch Effectors to Ensure Timely TransitionWe have shown that miR-7 is able to repress E(spl)m-gamma at the transition zone (Figure 3). [score:2]
Interestingly, homozygous mutants did not display defects in wing development that had previously been attributed to loss of miR-7 function (Aparicio et al., 2014). [score:2]
mir-7 Regulates Notch Effectors to Ensure Timely Transition. [score:2]
Brains are from (E) control (w1118; +; +); (F) miR-7 [CRISPR1]; (G) miR-7 [CRISPR1], Df E(spl)m- delta-m6; and (H) miR-7 [CRISPR1], Df(3)Brd-C1. [score:1]
miR-7 Is Sufficient to Promote the Transition from Neuroepithelial Cells to Neuroblasts and Is Necessary for Robust TransitionTo investigate the role of miR-7 at the transition zone, we generated a UAS- miR-7 construct and drove its expression in the neuroepithelium using c855a-GAL4 (Manseau et al., 1997). [score:1]
miR-7 acts via repression of downstream Notch effectors to limit Notch signaling and promote timely transition. [score:1]
HnRNP-K/miR-7 Stellaris Probes. [score:1]
The highly conserved microRNA miR-7 is produced from the primary transcript of heterogeneous nuclear ribonucleoprotein K (hnRNP-K) in both Drosophila (Li and Carthew, 2005) and humans (Choudhury et al., 2013). [score:1]
We have shown that miR-7 is able to repress E(spl)m-gamma at the transition zone (Figure 3). [score:1]
miR-7 [CRISPR1] is a 13-bp deletion that removes the 5′ 12 nt of the 23-nt miR-7 (Figure 2D) without disrupting neighboring genes. [score:1]
This raised the possibility that miR-7 could be acting as a biological buffer in the developing optic lobe, sufficient to promote transition but necessary only under conditions of physiological stress. [score:1]
To test whether miR-7 buffers the neuroepithelial-to-neuroblast transition, we subjected control and miR-7 [CRISPR1] mutant larvae to temperature stress, shifting developing larvae between 18°C and 31°C every 2 hr for 2 days. [score:1]
Temperature stress increased the severity of the disruption of proneural wave progression in miR-7 [CRISPR1] mutant brains (p = 0.049, Fisher’s exact test) but had no effect on control brains (p = 1, Fisher’s exact test) (Figures 4A–4C). [score:1]
Under normal laboratory conditions, the absence of miR-7 resulted in the sporadic disruption of the progression of the proneural wave. [score:1]
Similar to our observations in the optic lobe, miR-7 has been shown to play a role in photoreceptor differentiation (Li et al., 2009). [score:1]
miR-7 [CRISPR1] homozygous mutants were both viable and fertile. [score:1]
Therefore, miR-7 is sufficient to convert neuroepithelial cells into neuroblasts. [score:1]
This increase in severity of phenotype observed under temperature stress demonstrates that miR-7 buffers the neuroepithelial-cell-to-neuroblast transition. [score:1]
Predicted miR-7 binding sites can be found in the 3′ UTRs of many genes encoding downstream effectors and modulators of Notch pathway activity, including members of the Enhancer of split complex (E[spl]-C) and Bearded complex (Brd-C) (Kheradpour et al., 2007, Lai et al., 2005, Robins et al., 2005, Ruby et al., 2007). [score:1]
To investigate miR-7 function at the transition zone, we determined the precise expression pattern of hnRNP-K/miR-7 in the neuroepithelium. [score:1]
58.6% (n = 46) of F2 showed alterations to the miR-7 locus, generating a total of 20 independent alleles. [score:1]
In the absence of miR-7, proneural wave progression is disrupted. [score:1]
The available miR-7 allele is a 6.8-kb deletion generated by P-element excision that partially deletes both hnRNP-K and the downstream gene Hillarian (Li and Carthew, 2005). [score:1]
To assess whether miR-7 was necessary for the neuroepithelial-to-neuroblast transition, we generated miR-7 [CRISPR1] mutant clones that cross the transition zone (Figures 2E–2E″). [score:1]
Loss of miR-7 in miR-7 [CRISPR1] mutant clones resulted in a disruption of the normal E(spl)m-gamma-GFP pattern in a subset of clones, consistent with the observed delay in transition (Figures 3B and 3B′). [score:1]
miR-7 Is Sufficient to Promote the Transition from Neuroepithelial Cells to Neuroblasts and Is Necessary for Robust Transition. [score:1]
The following strains were generated: (miR-7)E > GFP (Li et al., 2009), m-gamma-GFP (Almeida and Bray, 2005), c855a-GAL4 (Manseau et al., 1997), w; Df[E(spl)m- delta-m6 XPd08311-RBe00084]/TM6B (Chanet et al., 2009), w1118; Df(3)Brd-C1/TM6B,Tb (Chanet et al., 2009), UAS- miR-7 (this study), miR-7 [CRISPR1] (this study), and FRT42D miR-7 [CRISPR1] (this study). [score:1]
To generate a miR-7 CRISPR allele, complementary oligos containing the guide RNA (gRNA) 5′-AAAATCACTAGTCTTCCATA-3′ flanked by BbsI overhangs were annealed and cloned into pCFD3 (Port et al., 2014). [score:1]
To investigate the role of miR-7 at the transition zone, we generated a UAS- miR-7 construct and drove its expression in the neuroepithelium using c855a-GAL4 (Manseau et al., 1997). [score:1]
mir-7 Buffers the Neuroepithelial-Cell-to-Neuroblast Transition. [score:1]
This disruption becomes more severe under conditions of temperature stress, suggesting that the role of miR-7 is to act as a buffer to ensure the timely and precise transition from neuroepithelial cells to neuroblasts in the developing optic lobe. [score:1]
Mutations in miR-7 were detected by sequencing of a 256-bp PCR product, amplified using primers that flank the gRNA cut site. [score:1]
miR-7 acts as a buffer to ensure that a precise and stereotypical pattern of transition is maintained, even under conditions of environmental stress, echoing the role that miR-7 plays in the eye imaginal disc. [score:1]
Generation of UAS-miR-7. Generation of miR-7 CRISPR Allele. [score:1]
miR-7 had been identified previously as a buffer in photoreceptor and proprioceptor determination (Li and Carthew, 2005, Li et al., 2009). [score:1]
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3
[+] score: 33
Target predictions at a reduced level of conservation (setting S1) also yield HLHm5 as the top-ranking miR-7 target. [score:5]
Another gene of the E(spl) complex, HLHm5, is the highest ranking target gene of miR-7 when searching for targets conserved in all flies (with setting S2; rank 2 with setting S3). [score:5]
We recovered four targets from this list (miR-7/HLHm5, miR-279/SP555, miR-124/Gli, and miR-310/imd) but failed to locate conserved nuclei for the other six targets (see comments in Table 3). [score:5]
Targets of miR-7 predicted by PicTar included many Notch pathway genes as well as targets of Notch signaling, including E(spl)m5, Tom, Bob, E(spl)mγ, Bearded, E(spl)m3, and E(spl)m4, most of which were very high scoring (using setting S1). [score:5]
There is experimental evidence that miR-7 also targets HLHm3 and E(spl)m4, two genes that are located in the E(spl) complex [4]. [score:3]
Our data were consistent with and extended results from a recent study that used GO functional analysis to predict microRNA target genes [4], in which miR-7 was predicted to be active in Notch signaling and miR-277 in valine, leucine, and isoleucine degradation. [score:3]
For HLHm3, PicTar predicts one miR-7 target site conserved in all flies (with all settings). [score:3]
The Notch signaling gene hairy was recently predicted [4, 9] and validated as a target of miR-7 with a single binding site [4]. [score:3]
PicTar found a miR-7 anchor site conserved in all flies of the melanogaster and obscura groups, whereas the site in D. virilis appears to be slightly shifted upstream. [score:1]
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4
[+] score: 28
Our analysis indicated that the WSSV early gene wsv477 was also targeted by host miR-7, suggesting that host might inhibit virus infection by targeting viral transcripts with host miRNAs. [score:7]
The miR-7 might act as a regulator of components of the immune system to inhibit virus replication through their direct interaction with viral mRNA. [score:5]
Phylogenetic analysis, target gene prediction and pathway analysis showed that, among the 13 conserved miRNAs (miR-1, miR-100, miR-10a, miR-124, miR-125, miR-184, miR-33, miR-34, miR-7, miR-9, miR-92a, miR-92b and miR-let7), several highly conserved miRNAs (miR-1, miR-7 and miR-34) targeted the same or similar genes leading to the same pathways in shrimp, fruit fly and human (Figure 3b). [score:5]
Among the differentially expressed miRNAs found, miR-1, miR-7 and miR-34 are highly conserved and mediate similar pathways, suggesting that some beneficial miRNAs have been preserved in animals during evolution. [score:3]
One of the predicted viral target genes of miR-7 was wsv477, an early gene that might have a key role in DNA replication and virus proliferation [33]. [score:3]
Our analyses predicted that miR-7, one of the miRNAs highly conserved between invertebrates and vertebrates, could target the mitogen-activated protein kinases (MAPKs), a situation identical to that in humans [43- 45]. [score:3]
Evolutionary analysis showed that three of them, miR-1, miR-7 and miR-34, are highly conserved in shrimp, fruit fly and humans and function in the similar pathways. [score:1]
In our study, phylogenetic analysis showed that the miR-1, miR-7 and miR-34 are highly conserved in shrimp, fruit fly and human and function in similar pathways. [score:1]
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5
[+] score: 16
Analogously, miRNAs have also been implicated in modulating gene expression during wing development 29, and includes the roles of miR-7 30, miR-iab-4 31, and miR-2a 32 (Table 3). [score:4]
Similarly, the expression of miR-7, Let-7, and miR-9a were 17.1-, 36.5-, 4.9- fold lower in wingless adults, respectively (Fig. 4D–F). [score:3]
Lane 1: 100 bp ladder marker; Lane 2: miR-315; Lane 4: miR-1; Lane 6: miR-9a; Lane 8: PC-5p-113190_15; Lane 10: PC-3p-2743_844; Lane 12: miR-7; Lane 14: miR-8; Lane 16: miR-277; Lane 18: Let-7. The other uneven lanes were negative controls for each target miRNA. [score:3]
The relative miRNA expression, including miR-277 (B), miR-1 (C), miR-7 (D), Let-7 (E), miR-9a (F), miR-315 (G), miR-8 (H), PC-5p-113190_15 (I), and PC-3p-2743_844 (J) at two wing morph was normalized to the wingless adult. [score:3]
For example, Let-7 and miR-7, comparatively, shares identical seed sequences across all insects (Fig. S1; Fig. S2). [score:1]
The RT-PCR amplified products for seven conserved miRNAs (Let-7, miR-1, miR-7, miR-277, miR-8, miR-9a and miR-315) and two novel miRNAs (PC-5p-113190_15 and PC-3p-2743_844) showed a single band in the expected size (60–100 bp) (Fig. 4A and S4). [score:1]
For example, miR-7 and let-7 were high conserved at the 5′ end of the mature sequence in comparison to other insects. [score:1]
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[+] score: 13
Other miRNAs from this paper: dme-mir-184, dme-mir-275, dme-bantam, dme-mir-310
Examples of post-transcriptional regulation of bam include the HOW RNA -binding protein (Monk et al. 2010) and miR-7, both of which have been implicated in binding to bam mRNA and downregulating bam expression (Pek et al. 2009). [score:7]
Another RNA binding protein, Maelstrom (Mael), is required in spermatogonia to repress miR-7 and upregulate bam expression so that the transit-amplification can proceed normally (Pek et al. 2009). [score:6]
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7
[+] score: 12
Since loqs mRNA expression is lowest in the ovaries of loqs [f00791] mutant flies, we analyzed the levels of pre-miR-7 and mature miR-7, a miRNA that is expressed in whole males, manually dissected ovaries, and the female carcasses remaining after removing the ovaries (Figure 2B). [score:5]
The loqs [f00791] mutation caused pre-miRNAs to accumulate in the soma and the germ line and strongly reduced mature miR-7 levels in the female germ line, suggesting that Loqs function is required for miRNA-directed silencing in vivo. [score:3]
While pre-miR-7 increased in all loqs [f00791] homozygous mutant tissues, relative to wild-type or loqs heterozygotes, the disruption of miR-7 production in ovaries was striking: not only did pre-miR-7 accumulate, but also mature miR-7 was dramatically reduced. [score:1]
Thus, Loqs is required for production in vivo of normal levels of miR-7, miR-277, and bantam, and the efficient conversion of pre- let-7 to mature let-7 in vitro. [score:1]
The following probes were used for detection: 5′-UCG UAC CAG AUA GUG CAU UUU CA-3′ for miR-277; 5′-CAG CTT TCA AAA TGA TCT CAC T-3′ for bantam; 5′-ACA ACA AAA UCA CUA GUC UUC CA-3′ for miR-7; 5′-TAC AAC CCT CAA CCA TAT GTA GTC CAA GCA-3′ for 2S rRNA. [score:1]
shtml) accession numbers for the genes and gene products discussed in this paper are: bantam (MI0000387), let-7 (MI0000416), miR-277 (MI0000360), miR-7 (MI0000127), and TAR (RF00250). [score:1]
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8
[+] score: 11
Other miRNAs from this paper: dme-mir-5, dme-mir-6-1, dme-mir-6-2, dme-mir-6-3, dme-bantam
Overexpression of mir-7 in the patch territory induces a distal wing notch in control flies, that is suppressed by Ago1 and pasha RNAi knockdowns but not by Ago2 RNAi knockdown. [score:7]
The silencing efficiency of Ago1 RNAi in the patch territory was demonstrated by the suppression of the Ago1 -dependent miR-7 effect in the wing (Fig. 2F and [37]. [score:3]
Wings from ptc-GAL4>UAS-mir-7 adult flies in the presence of the UAS-GFP transgene as a control or of the hairpin transgenes UAS-IR[Ago1], UAS-IR[Ago2] or UAS-IR[pasha] are shown. [score:1]
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9
[+] score: 9
All selected miRNAs that change in expression upon Dis3-depletion in the miRNA-seq data also significantly change in expression when using qRT-PCR (except miR-7–3p). [score:5]
Using this stringent filtering method, we identified 6 miRNAs whose expression increased ≥2-fold in the knockdown samples compared to both parental controls (miR-277–3p, miR-987–5p, miR-252–5p, miR-34–5p, and miR-7–3p and miR-317–5p). [score:3]
Figure 6B shows that the changes in expression levels for all selected miRNAs, as measured by qRT-PCR, were comparable with the levels determined by RNA-seq, apart from for miR-7–3p which had a very low normalized read count. [score:1]
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[+] score: 8
This is exemplified by miR-7, which has been shown to contribute to the robustness of regulatory networks that ensure correct sense organ specification in Drosophila [7]. [score:2]
The requirement for miR-7 activity in these patterning processes is not evident under normal, environmentally stable, conditions. [score:1]
In both examples miR-7 is induced by one of the transcription factors to confer repression on the other. [score:1]
miR-7 was shown to act in two molecularly distinct feed-forward loops required for sense organ specification [7]. [score:1]
In the miR-7 case, the mutants do not show any defect under normal conditions, but the limits to the robustness of the system can be revealed by environmental perturbation. [score:1]
Although miR-7 is not required under normal conditions, SOP patterning was compromised when miR-7 mutant flies were subjected to environmentally challenging conditions. [score:1]
Thus miR-7 acts to provide stability to these molecular networks. [score:1]
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[+] score: 6
Therefore, we expressed an eGFP reporter that contained two perfect binding sites for the miRNA miR-7 in its 3′UTR. [score:3]
The tub > eGFP:: Hid, arm > LacZ:: E(spl)m8, and tub > eGFP:: 2x(miR-7) transgenes were described previously (Brennecke et al. 2003; Lai and Posakony 1997; Li and Carthew 2005). [score:1]
Binding sites for miR-4/-79 (red) and miR-7 (blue) are indicated in the Brd 3′UTR. [score:1]
This UTR has been experimentally demonstrated to contain three binding sites for miR-4/miR-79 and one binding site for miR-7 (Lai et al. 2005). [score:1]
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12
[+] score: 5
In addition, the presence of miR-7 in this region may also be significant given that miR-7 inhibits neuronal apoptosis in a cellular Parkinson’s disease mo del (Li et al. 2016) and contributes to the alteration of neuronal morphology and function (Zhang et al. 2015). [score:5]
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13
[+] score: 4
Other miRNAs from this paper: dan-mir-7, dvi-mir-7
However, only four target genes are currently known for Ato, namely sens, dap, Brd, and mir-7, yielding a poor explanation of the regulatory network underlying the complex process of Ato -dependent neural fate specification [30]– [33]. [score:4]
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14
[+] score: 4
Other miRNAs from this paper: dme-mir-92a, dme-mir-9c, dme-mir-969
miRNAs typically act on hundreds of target transcripts, and some miRNAs have been shown to stabilize regulatory networks, e. g., Drosophila miR-7 (Li et al. 2009). [score:4]
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[+] score: 4
These included miR-SPs targeting bantam, miR-1, the K-box family (miR-2b, miR-2c and miR-13b displayed strong phenotypes; miR-2a and miR-13a were flight impaired but fell below our stringent cutoff; ), miR-7, the miR-31 family, miR-34, miR-190, miR-957, miR-986, miR-987 and miR-1001. [score:3]
Recent studies suggest that vertebrate orthologues for several of the conserved miRNAs required for muscle maintenance in our screen (miR-1, miR-7, miR-31 and miR-34, and the K-box orthologue miR-23) are associated with muscle physiology in vertebrate species (Supplementary Table 1). [score:1]
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16
[+] score: 4
For example, miR-315 and miR-8 regulate components of the Wg pathway, while miR-1 and miR-7 regulate N pathway components during fly development (reviewed by [136]). [score:4]
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[+] score: 4
Other miRNAs from this paper: dme-mir-79, bmo-mir-7, bmo-mir-79
Indeed, two E(spl)-C genes that contain GY boxes have been validated as targets of miR-7 [34]. [score:3]
The minimum free energy for hybridization as predicted by mFold analysis is −28.2 kcal/mol between BmEm4 and bmo-mir-7 and −17.6 kcal/mol between BmEm4 and bmo-mir-79 (Figure 8(a)). [score:1]
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[+] score: 3
Similarly, miR-2 and miR-7 control signal transduction pathways (notch signalling) in both Drosophila sp and B. mori by targeting HLHmδ, HLHm3, HLHm5, HLHmγ, M4 and TOM [33, 34]. [score:3]
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[+] score: 3
mir-2 controls HLHm delta, and mir-7 controls HLHm3, HLHm5, HLHmgamma, M4 and TOM, in D. melanogaster; these six genes are involved in the Notch signaling pathway. [score:1]
4220] of these six genes can bind perfectly to mir-2 (bmo-miR-2a, bmo-miR-2b, bmo-miR-13a* and bmo-miR-13b) and bmo-miR-7, respectively. [score:1]
mir-2 and mir-7 may be related to the Notch signaling pathway in B. mori; this hypothesis is consistent with previous predictions [38, 53]. [score:1]
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[+] score: 3
As α-synuclein inclusions is the major component of Lewy body, miRNAs (miR-34b, miR-34c, miR-153 and miR-7) could target 3’UTR of α-synuclein and ameliorate its toxic effects [53, 54]. [score:3]
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21
[+] score: 3
Several evidence also suggest than B2 sequesters siRNA duplexes, preventing their loading into Ago-2. In contrast, both these VSRs failed to inhibit the silencing of reporter systems by the endogenous miRNAs miR-2b, bantam or miR-7 [35– 37]. [score:3]
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[+] score: 3
CDR1 antisense transcript (CDR1as) is a circular RNA in mouse and human brain that contains more than 70 binding sites for the microRNA miR-7 and may suppress its activity. [score:3]
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[+] score: 3
For example, it has been shown that the conserved miRNA miR7 is not essential for the development of Drosophila raised under optimal culture conditions, but is required to maintain sensory organ fate under fluctuating temperature conditions [46], providing an important aspect of phenotypical robustness for developmental programs. [score:3]
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[+] score: 2
Other miRNAs from this paper: hsa-mir-7-1, hsa-mir-7-2, hsa-mir-7-3, hsa-mir-34a, hsa-mir-124-1, hsa-mir-124-2, mmu-mir-34a, osa-MIR169a, mmu-mir-124-1, mmu-mir-124-2, mmu-mir-7a-1, mmu-mir-7a-2, mmu-mir-7b, cel-mir-354, osa-MIR159a, osa-MIR159b, osa-MIR159c, osa-MIR159d, osa-MIR159e, osa-MIR159f, osa-MIR319a, osa-MIR319b, osa-MIR168a, osa-MIR169b, osa-MIR169c, osa-MIR169d, osa-MIR169e, osa-MIR169f, osa-MIR169g, osa-MIR169h, osa-MIR169i, osa-MIR169j, osa-MIR169k, osa-MIR169l, osa-MIR169m, osa-MIR169n, osa-MIR169o, osa-MIR169p, osa-MIR169q, mtr-MIR169a, mtr-MIR319a, ptc-MIR159a, ptc-MIR159b, ptc-MIR159d, ptc-MIR159e, ptc-MIR159c, ptc-MIR168a, ptc-MIR169a, ptc-MIR169aa, ptc-MIR169ab, ptc-MIR169ac, ptc-MIR169ad, ptc-MIR169ae, ptc-MIR169af, ptc-MIR169b, ptc-MIR169c, ptc-MIR169d, ptc-MIR169e, ptc-MIR169f, ptc-MIR169g, ptc-MIR169h, ptc-MIR169i, ptc-MIR169j, ptc-MIR169k, ptc-MIR169l, ptc-MIR169m, ptc-MIR169n, ptc-MIR169o, ptc-MIR169p, ptc-MIR169q, ptc-MIR169r, ptc-MIR169s, ptc-MIR169t, ptc-MIR169u, ptc-MIR169v, ptc-MIR169w, ptc-MIR169x, ptc-MIR169y, ptc-MIR169z, ptc-MIR319a, ptc-MIR319b, ptc-MIR319c, ptc-MIR319d, ptc-MIR319e, ptc-MIR319f, ptc-MIR319g, ptc-MIR319h, ptc-MIR319i, hsa-mir-519b, ppt-MIR319a, ppt-MIR319b, ppt-MIR319c, ppt-MIR319d, mtr-MIR169c, mtr-MIR169d, mtr-MIR169e, mtr-MIR169f, mtr-MIR319b, mtr-MIR168a, mtr-MIR169g, mtr-MIR169h, mtr-MIR169b, ppt-MIR319e, osa-MIR169r, mtr-MIR159a, mtr-MIR169k, mtr-MIR169j, mtr-MIR159b, ptc-MIR169ag, mtr-MIR169i, mtr-MIR319c, mtr-MIR319d, mtr-MIR169l
Notice that only miRNA-like RNAs on miR7 precursors in human and mouse are conserved (Table 2; Figure 7c; Additional files 7 and 8). [score:1]
It is also interesting to note that miR7 in Drosophila has diverged from that in human and mouse significantly (data not shown), and miR7 has not been reported in C. elegans. [score:1]
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Other miRNAs from this paper: dme-bantam
Northern blots for bantam and mir-7 miRNAs reveal no differences in quantity of mature miRNA in lump [1] mutant flies. [score:1]
We performed Northern blot analysis to examine the levels of bantam and mir-7, two microRNAs, in wild type and lump [1] mutants. [score:1]
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In fact, many of these miRNAs, such as the let-7 family, mir-29 family, mir-26 family, mir-140-3p, mir-30d, mir-7, mir-191, mir-21, mir-100, mir-15a, and mir-16, play an important role in development and differentiation [36- 41]. [score:2]
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For example, a Drosophila mir-7 mutant exhibits minor cell specification defects, but these are enhanced by heat shock [58]. [score:1]
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And ten pre-miRNAs also predicted mature parts on the star (*) arm (mir-305, mir-79, let-7, mir-2a-2, mir-8, mir-7, mir-9a, mir-316, mir-34, mir-12). [score:1]
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[+] score: 1
The newly discovered circRNA sponge for miR-7 (CiRS-7) was found to be a potent sponge for cellular miR-7, causing reduction in the active miR-7 pool [2, 4]. [score:1]
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As reference genes we used dme-miR-7 and dme-miR-8. Expression level determinations were performed using an Applied Biosystems Step One Plus Real Time PCR System and the values were calculated using the 2 [−∆∆Ct]. [score:1]
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For instance, in mammalian genomes mir-7 is clustered with mir-1179, a mammal-specific microRNA, showing that the creation of new clusters by new hairpin formation also happens in other clades (Table 2). [score:1]
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