microRNA（miRNA）途徑參與許多生物學(xué)過(guò)程。本文中,，研究人員在線蟲(chóng)中對(duì)于miRNA途徑中兩個(gè)特異蛋白進(jìn)行了研究，試圖發(fā)現(xiàn)miRNA在調(diào)節(jié)生物學(xué)事件中更多的功能。
ALG-1和ALG2是Argonaute蛋白家族的成員，研究人員發(fā)現(xiàn),，突變的ALG-1和ALG-2會(huì)導(dǎo)致線蟲(chóng)的子代數(shù)量減少。進(jìn)一步分析顯示,，在ALG-1和ALG-2突變的個(gè)體中,，有絲分裂的生殖細(xì)胞減少，并且有一部分細(xì)胞會(huì)提前進(jìn)入減數(shù)分裂階段,。在野生型線蟲(chóng)中，ALG-1特異表達(dá)在頂端細(xì)胞（distal tip cell,，DTC),。在頂端細(xì)胞內(nèi)表達(dá)有功能的ALG-1可以一定程度上修復(fù)突變體中生殖細(xì)胞的缺陷。有趣的是,，阻礙5個(gè)miRNA的表達(dá)也會(huì)導(dǎo)致類似的表型,。
研究人員表示，這一結(jié)果說(shuō)明,，microRNA途徑調(diào)節(jié)線蟲(chóng)生殖細(xì)胞的增殖和分化中起著重要的作用,，同時(shí)該研究也揭示了miRNA的一項(xiàng)新功能。（生物谷 Bioon.com ）
doi:10.1038/cr.2012.31
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The microRNA pathway controls germ cell proliferation and differentiation in C. elegans
Syed Irfan Ahmad Bukhari, Alejandro Vasquez-Rifo, Dominic Gagné, Eric R Paquet, Monique Zetka, Claude Robert, Jean-Yves Masson and Martin J Simard
The discovery of the miRNA pathway revealed a new layer of molecular control of biological processes. To uncover new functions of this gene regulatory pathway, we undertook the characterization of the two miRNA-specific Argonaute proteins in Caenorhabditis elegans, ALG-1 and ALG-2. We first observed that the loss-of-function of alg-1 and alg-2 genes resulted in reduced progeny number. An extensive analysis of the germline of these mutants revealed a reduced mitotic region, indicating fewer proliferating germ cells. We also observed an early entry into meiosis in alg-1 and alg-2 mutant animals. We detected ALG-1 and ALG-2 protein expressions in the distal tip cell (DTC), a specialized cell located at the tip of both C. elegans gonadal arms that regulates mitosis-meiosis transition. Re-establishing the expression of alg-1 specifically in the DTC of mutant animals partially rescued the observed germline defects. Further analyses also support the implication of the miRNA pathway in gametogenesis. Interestingly, we observed that disruption of five miRNAs expressed in the DTC led to similar phenotypes. Finally, gene expression analysis of alg-1 mutant gonads suggests that the miRNA pathway is involved in the regulation of different pathways important for germline proliferation and differentiation. Collectively, our data indicate that the miRNA pathway plays a crucial role in the control of germ cell biogenesis in C. elegans.
