成熟精子中RNA 的發(fā)現(xiàn)讓科學(xué)家意識(shí)到精子不僅僅是運(yùn)輸父源DNA的載體,，過去的研究已證實(shí)成熟精子所攜帶的一些miRNA能夠影響早期胚胎發(fā)育及后代的性狀,。然而,，目前尚不清楚成熟精子中是否還攜帶除miRNA之外其他種類的小RNA,；對各種小RNA的生成及在成熟精子中的富集過程也知之甚少,。
動(dòng)物所段恩奎,、韓春生和周琪三個(gè)實(shí)驗(yàn)室合作,，從小鼠附睪尾分離得到高純度的成熟精子,，通過對其中的小分子RNA (18-40 nt) 深度測序結(jié)果分析，發(fā)現(xiàn)成熟精子中大量存在一類來源于tRNA的小分子RNA,。這類小RNA的長度主要富集于29-34nt,，類似但不同于睪丸中的piRNA；序列分析發(fā)現(xiàn)這類小RNA均來源于成熟tRNA的5’端序列,?；谶@類小RNA在成熟精子中的高富集性及其tRNA來源，將其命名為mse-tsRNAs (mature-sperm-enriched tRNA derived small RNAs),。mse-tsRNAs的含量占小鼠精子小RNA測序reads總量的67.54%,；相比之下，精子中所有miRNA的總和僅占4.61%,。mse-tsRNAs的表達(dá)量是從生精的晚期或離開睪丸（在附睪中）時(shí)開始迅速上升,，提示這一時(shí)期存在特異的蛋白負(fù)責(zé)其剪切及富集。在成熟精子中,，mse-tsRNAs 在精子頭部富集,，說明其能夠在受精時(shí)進(jìn)入卵細(xì)胞。
由于tRNA在進(jìn)化上高度保守,，tRNA來源的mse-tsRNAs 也在脊椎動(dòng)物中呈高度保守,，提示他們可能作為一種古老的父源信息在受精時(shí)傳遞給卵細(xì)胞。研究mse-tsRNA的生成/富集機(jī)制及其生物學(xué)功能將是下一步最為重要的工作,。
該課題得到科技部,、自然科學(xué)基金委和中國科學(xué)院的資助。文章于10月9日在Cell Research 雜志在線發(fā)表,。（生物谷Bioon.com）
doi: 10.1038/cr.2012.141
PMC:
PMID:
A novel class of tRNA-derived small RNAs extremely enriched in mature mouse sperm
Hongying Peng, Junchao Shi, Ying Zhang, He Zhang, Shangying Liao, Wei Li, Li Lei, Chunsheng Han, Lina Ning, Yujing Cao, Qi Zhou, Qi Chen and Enkui Duan
The discovery of sperm-borne RNAs (mRNAs and small non-coding RNAs) has opened the possibility of additional paternal contributions aside from providing the DNA. It has been reported that the incoming sperm can provide information for its host egg cytoplasm, which functionally influences the order of cell division, possibly via delivering RNAs. Indeed, the sperm-borne miRNA and mRNA have been demonstrated as active players in early embryo development and transgenerational epigenetic inheritance. However, given the diversity of small RNA classes (miRNA, endo-siRNA, piRNA, etc.) generated during spermatogenesis, the contents and profiles of the small RNA population carried by mature sperm remain undefined. In the present study, we isolated mature sperm from the cauda epididymis of adult male mice. The purity of sperm was > 99% as evaluated by microscopy and was confirmed by RT-PCR analyses of different biomarkers . The RNA extracted from mature sperm, adult testis, and uterus were processed for small RNA (< 40 nt) deep sequencing
