Genomic organization and embryonic expression of miR-430 in medaka (Oryzias latipes): insights into the post-transcriptional gene regulation in early development.
Genomic organization and embryonic expression of miR-430 in medaka (Oryzias latipes): insights into the post-transcriptional gene regulation in early development.
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DOI：
10.1016/j.gene.2009.09.005
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发表时间：
2010
期刊：
影响因子：
3.5
通讯作者：
Saori Tani;R. Kusakabe;K. Naruse;H. Sakamoto;Kunio Inoue
中科院分区：
文献类型：
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作者：
Saori Tani;R. Kusakabe;K. Naruse;H. Sakamoto;Kunio Inoue
MicroRNA（miRNA、miR）是短的非编码 RNA 分子，可通过与 3' 非翻译区 (UTR) 结合来负控制靶 mRNA。先前的研究表明，miR-430 由簇状多基因家族编码，并在早期发育中大量表达。在斑马鱼中，需要 miR-430 来抑制体细胞中原始生殖细胞 (PGC) 特异性基因，例如 nanos1。然而，其他硬骨鱼物种中miR-430家族的分子特征尚未见报道，并且尚不清楚PGC规范中miR-430的这种功能是否是动物的保守特征。在青鳉（Oryzias latipes）这种远缘硬骨鱼中，有人认为 PGC 可能以与斑马鱼不同的规范模式建立。我们对青鳉基因组序列中的 16 个 miR-430 前体进行了表征。这些 miR-430 基因在 4 号染色体上形成簇，其进化起源可能与斑马鱼 4 号染色体上非常大的 miR-430 簇的进化起源相同。然而，青鳉鱼 miR-430 基因中没有一个与斑马鱼 miR-430 旁系同源基因相同。 Medaka miR-430 表达在外旋过程中开始，并在轴形成后减少。使用报告基因构建体进行的功能分析表明，miR-430 通过与斑马鱼 TDRD7 的 3'UTR 结合来抑制蛋白质表达。一致地，青鳉 TDRD7 的 3'UTR 至少包含两个重要的候选 miR-430 结合位点。青鳉 miR-430 的普遍早期表达及其下调 GFP:TDRD7 报告基因 mRNA 的能力表明 miR-430 在早期胚胎发生中具有保守的作用。青鳉中 miR-430 基因的较小拷贝数和相对短暂的表达可能代表了硬骨鱼共同祖先中该 miRNA 家族的特征。 miR-430与靶mRNA关系的变化可能与青鳉鱼和斑马鱼中PGC相关基因的定位模式差异有关。
MicroRNAs (miRNAs, miRs) are short noncoding RNA molecules that negatively control the target mRNAs by binding to the 3′ untranslated region (UTR). Previous studies have demonstrated that miR-430 is encoded by a clustered multigene family and is abundantly expressed in early development. In zebrafish, miR-430 is needed to suppress primordial germ cell (PGC)-specific genes, such as nanos1, in somatic cells. However, the molecular characteristics of the miR-430 family in other teleost species have not been reported, and it is unclear whether such a function of miR-430 in PGC specification is a conserved feature of animals or not. In medaka (Oryzias latipes), a distantly related teleost, it has been suggested that PGC might be established in a different mode of specification from that of zebrafish. We characterized 16 miR-430 precursors in the medaka genomic sequence. These miR-430 genes form clusters on chromosome 4, which might share its evolutionary origin with that of the very large miR-430 clusters in zebrafish chromosome 4. However, none of the medaka miR-430 genes are identical to the zebrafish miR-430 paralogs. Medaka miR-430 expression starts during epiboly and decreases after axis formation. Functional analysis using reporter gene constructs showed that miR-430 repressed protein expression by binding to the 3′UTR of zebrafish TDRD7. Consistently, the 3′UTR of medaka TDRD7 contains at least two significant candidates for the putative miR-430 binding site. The ubiquitous and early expression of medaka miR-430 and its ability to downregulate GFP:TDRD7 reporter mRNA imply that miR-430 has a conserved role in early embryogenesis. Smaller copy numbers of miR-430 genes and relatively brief expression in medaka might represent the characteristics of this miRNA family in the common ancestor of teleosts. Changes in the relationships between miR-430 and the target mRNA might be related to differences in the localization patterns of PGC-related genes in medaka and zebrafish.