日本研究人員8月4日?qǐng)?bào)告說(shuō),，他們成功將實(shí)驗(yàn)鼠胚胎干細(xì)胞轉(zhuǎn)化為健康精子,，并最終培育出健康且具生殖能力的小老鼠。這項(xiàng)研究有望為男性不育者帶來(lái)福音,。
日本京都大學(xué)教授齋藤通紀(jì)等人在美國(guó)《細(xì)胞》雜志網(wǎng)絡(luò)版上說(shuō)，他們首先將實(shí)驗(yàn)鼠胚胎干細(xì)胞轉(zhuǎn)化為原始生殖細(xì)胞,，并將其植入不能正常產(chǎn)生精子的實(shí)驗(yàn)鼠體內(nèi),，原始生殖細(xì)胞此后開始產(chǎn)生正常形態(tài)的精子,，這些精子能夠使卵子受精,。
研究人員寫道：“植入受精卵的受體實(shí)驗(yàn)鼠產(chǎn)下的后代很健康，發(fā)育正常,，無(wú)論雌雄，都具有生殖能力,。”
利用干細(xì)胞培養(yǎng)“人造精子”的研究由來(lái)已久。早在2003年,，就有數(shù)個(gè)研究小組聲稱制造出“人造精子”，但讓實(shí)驗(yàn)鼠懷孕的努力以失敗告終,。
2006年，英國(guó)紐卡斯?fàn)柎髮W(xué)一個(gè)研究小組利用胚胎干細(xì)胞制造出“人造精子”,，并培育7只小老鼠，但7只小老鼠均出現(xiàn)健康問題并夭折,。3年后，這個(gè)研究小組又宣布成功利用人類干細(xì)胞培育出成熟精子,，不過(guò)這篇論文很快因兩段內(nèi)容涉嫌剽竊被撤銷,。
一些科學(xué)家對(duì)成功培養(yǎng)“人造精子”的消息感到無(wú)比激動(dòng)，稱之為“巨大突破”,。但也有科學(xué)家說(shuō)，這一技術(shù)應(yīng)用于人類之前,，還需要克服不少技術(shù)和倫理難題。參與研究的齋藤通紀(jì)也表示，要將這一技術(shù)應(yīng)用在人類身上“仍有很長(zhǎng)一段路要走”,。（生物谷 Bioon.com）
doi:10.1016/j.cell.2011.06.052
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Reconstitution of the Mouse Germ Cell Specification Pathway in Culture by Pluripotent Stem Cells
Katsuhiko Hayashi, Hiroshi Ohta, Kazuki Kurimoto, Shinya Aramaki, Mitinori Saitou
The generation of properly functioning gametes in vitro requires reconstitution of the multistepped pathway of germ cell development. We demonstrate here the generation of primordial germ cell-like cells (PGCLCs) in mice with robust capacity for spermatogenesis. PGCLCs were generated from embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) through epiblast-like cells (EpiLCs), a cellular state highly similar to pregastrulating epiblasts but distinct from epiblast stem cells (EpiSCs). Reflecting epiblast development, EpiLC induction from ESCs/iPSCs is a progressive process, and EpiLCs highly competent for the PGC fate are a transient entity. The global transcription profiles, epigenetic reprogramming, and cellular dynamics during PGCLC induction from EpiLCs meticulously capture those associated with PGC specification from the epiblasts. Furthermore, we identify Integrin-β3 and SSEA1 as markers that allow the isolation of PGCLCs with spermatogenic capacity from tumorigenic undifferentiated cells. Our findings provide a paradigm for the first step of in vitro gametogenesis.
