基因重復(fù)是新基因和新功能產(chǎn)生的最主要的方式之一,。然而,，在分子水平，新產(chǎn)生的重復(fù)基因如何通過通路整合而獲得生物學(xué)功能以及產(chǎn)生適應(yīng)性性狀卻并不清楚,。
為了回答以上問題,，中科院昆明動物研究所中德馬普進(jìn)化基因組學(xué)青年科學(xué)家小組的博士生丁昀等在導(dǎo)師王文研究員的指導(dǎo)下，對黑腹果蠅亞群（Drosophila melanogaster subgroup）里新近產(chǎn)生的kep1基因家族的生物學(xué)功能及分子機(jī)制進(jìn)行了研究,。通過序列和表達(dá)分析,，他們發(fā)現(xiàn)其中的一個新基因nsr（novel spermatogenesis regulator）在進(jìn)化過程中受到了強(qiáng)烈的達(dá)爾文正選擇的作用，并顯出了新的亞細(xì)胞定位特征,?；蚯贸腿D(zhuǎn)錄組測序分析的結(jié)果則進(jìn)一步表明，nsr通過轉(zhuǎn)錄后調(diào)節(jié)幾個重要的Y染色體連鎖的育性因子參與精子的個體化（sperm individualization）和卷曲折疊（sperm coiling）過程,，并對精子軸絲結(jié)構(gòu)的完整性有重要貢獻(xiàn),。此外，外群物種里的祖先基因缺乏同nsr相似的精巢表達(dá)模式但具備相應(yīng)的順式調(diào)控元件說明：祖先基因在重復(fù)前對雄性生殖力應(yīng)該無明顯作用,；反式調(diào)控元件的變化很可能通過賦予nsr新的表達(dá)模式而促使它經(jīng)歷新功能化（neofunctionalization）的過程,。
該研究不但刻畫了一個年輕重復(fù)基因進(jìn)化的詳盡歷程，而且表明新近起源的年輕新基因可以通過調(diào)控已有的重要基因來建立新的功能通路和捕獲多種生物學(xué)功能,。同時,，新基因參與古老的重要的生物學(xué)過程這一結(jié)果也有助于我們解釋不同生物體同一生物學(xué)過程往往很可能由不同的基因來參與調(diào)節(jié)的普遍自然現(xiàn)象。
該論文已于2010年12月發(fā)表于PLoS Genetics雜志上（IF=9.532）,。（生物谷Bioon.com）
生物谷推薦原文出處：
PLoS Genet. doi:10.1371/journal.pgen.1001255
A Young Drosophila Duplicate Gene Plays Essential Roles in Spermatogenesis by Regulating Several Y-Linked Male Fertility Genes
Yun Ding1,2#, Li Zhao1,2#, Shuang Yang1, Yu Jiang1,2, Yuan Chen1,2, Ruoping Zhao1, Yue Zhang1, Guojie Zhang1,2, Yang Dong1,2, Haijing Yu3, Qi Zhou1,2¤, Wen Wang1*
1 State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China, 2 Graduate University of Chinese Academy of Sciences, Beijing, China, 3 Laboratory for Conservation and Utilization of Bio-Resources and Human Genetics Center of Yunnan University, Kunming, China
Abstract
Gene duplication is supposed to be the major source for genetic innovations. However, how a new duplicate gene acquires functions by integrating into a pathway and results in adaptively important phenotypes has remained largely unknown. Here, we investigated the biological roles and the underlying molecular mechanism of the young kep1 gene family in the Drosophila melanogaster species subgroup to understand the origin and evolution of new genes with new functions. Sequence and expression analysis demonstrates that one of the new duplicates, nsr (novel spermatogenesis regulator), exhibits positive selection signals and novel subcellular localization pattern. Targeted mutagenesis and whole-transcriptome sequencing analysis provide evidence that nsr is required for male reproduction associated with sperm individualization, coiling, and structural integrity of the sperm axoneme via regulation of several Y chromosome fertility genes post-transcriptionally. The absence of nsr-like expression pattern and the presence of the corresponding cis-regulatory elements of the parental gene kep1 in the pre-duplication species Drosophila yakuba indicate that kep1 might not be ancestrally required for male functions and that nsr possibly has experienced the neofunctionalization process, facilitated by changes of trans-regulatory repertories. These findings not only present a comprehensive picture about the evolution of a new duplicate gene but also show that recently originated duplicate genes can acquire multiple biological roles and establish novel functional pathways by regulating essential genes.
