导读：美国哈佛大学研究员却提出新理论，年轻女性卵巢内存在少量能够分化形成卵细胞的“干细胞”。蒂利的新发现有望为不孕症治疗带来新可能。不过，业内学者态度谨慎。堪萨斯大学生殖学中心主任戴维•阿尔贝蒂尼则认为，即便卵巢“干细胞”成功分化形成卵细胞，它们能否可以受精发育仍旧未解。
研究发现女性卵细胞或可“再造”
据新华社消息，多年来学界观点一直认为，女性一生所能生成的卵细胞数量自出生时已经确定。然而，美国哈佛大学研究员却提出新理论，年轻女性卵巢内存在少量能够分化形成卵细胞的“干细胞”。
哈佛医学院下属马萨诸塞综合医院研究员乔纳森•蒂利在26日出版的英国《自然－医学》杂志中撰文说，他所领导的研究小组与日本崎玉医科大学合作，以２０多岁女子经变性手术切除的冷冻健康卵巢为研究对象。
研究人员把卵巢移植到老鼠皮肤下，以获取血液营养。然后，通过卵巢“干细胞”所特有的表层蛋白质，研究小组锁定目标，继而“插入”呈绿色的识别基因，观察分化过程。
蒂利说，两周时间内，发现携带绿色基因的卵细胞形成。
蒂利的新发现有望为不孕症治疗带来新可能。不过，业内学者态度谨慎。堪萨斯大学生殖学中心主任戴维•阿尔贝蒂尼则认为，即便卵巢“干细胞”成功分化形成卵细胞，它们能否可以受精发育仍旧未解。
Oocyte formation by mitotically active germ cells purified from ovaries of reproductive-age women
Yvonne A R White, Dori C Woods, Yasushi Takai, Osamu Ishihara, Hiroyuki Seki & Jonathan L Tilly
Germline stem cells that produce oocytes in vitro and fertilization-competent eggs in vivo have been identified in and isolated from adult mouse ovaries. Here we describe and validate a fluorescence-activated cell sorting-based protocol that can be used with adult mouse ovaries and human ovarian cortical tissue to purify rare mitotically active cells that have a gene expression profile that is consistent with primitive germ cells. Once established in vitro, these cells can be expanded for months and can spontaneously generate 35- to 50-μm oocytes, as determined by morphology, gene expression and haploid (1n) status. Injection of the human germline cells, engineered to stably express GFP, into human ovarian cortical biopsies leads to formation of follicles containing GFP-positive oocytes 1–2 weeks after xenotransplantation into immunodeficient female mice. Thus, ovaries of reproductive-age women, similar to adult mice, possess rare mitotically active germ cells that can be propagated in vitro as well as generate oocytes in vitro and in vivo.
文献链接：https://www.nature.com/nm/journal/vaop/ncurrent/full/nm.2669.html
