12月3日,，中科院生物物理所張宏研究組以Residual body removal during spermatogenesis in C. elegans requires genes that mediate cell corpse clearance為題，在最新一期 Development 上發(fā)表了最新研究成果,。文中報道了線蟲精子發(fā)育過程中殘余體的清除與線蟲中凋亡細胞的清除有相似的分子機制。
在哺乳動物精子發(fā)育過程中,，大部分細胞質(zhì)被分離形成殘余體,，殘余體脫離精子進而被降解。然而對于降解殘余體的具體分子細胞機制還有許多未知,。在這篇文章中,，我們發(fā)現(xiàn)秀麗線蟲精子發(fā)育過程中產(chǎn)生的殘余體被性腺鞘細胞吞入并降解，參與凋亡細胞降解的一系列基因同時參與其中,。清除凋亡細胞的兩條冗余信號通路通過識別殘體表面的”eat me”信號磷脂酰絲氨酸,，也參與了殘余體的吞噬。包裹殘余體的吞噬小體通過動態(tài)包被PtdIns(3)P,，招募RAB小GTP水解酶等一系列過程完成成熟,。雌雄同體線蟲殘余體的清除與凋亡細胞的清除有相似過程，但雄性線蟲殘余體的清除所需吞噬基因又有所不同,。殘余體的高效清除保證了精子的數(shù)目和交配過程中精子的有效輸出,。我們的研究表明秀麗線蟲精子發(fā)育過程中產(chǎn)生的殘余體通過與凋亡細胞相同的吞噬通路被清除。該研究提供了除凋亡細胞外,，探索吞噬通路分子機制的一個新的遺傳模型,。
張宏實驗室與北大醫(yī)學(xué)部聯(lián)合培養(yǎng)的博士生黃潔與北京生命科學(xué)研究所王曉晨實驗室的博士生王海彬為本文共同第一作者，張宏博士和王曉晨博士為本文共同通訊作者,。該項研究由國家基礎(chǔ)研究基金973資助,，張宏博士和王曉晨博士的研究獲得HHMI國際青年科學(xué)家獎支持，在中科院生物物理所和北京生命科學(xué)研究所完成,。（生物谷Bioon.com）
doi:10.1242/dev.086769
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Residual body removal during spermatogenesis in C. elegans requires genes that mediate cell corpse clearance
Jie Huang, Haibin Wang, Yingyu Chen, Xiaochen Wang, and Hong Zhang
Generation of spermatozoa involves segregation of most of the cytoplasm into residual bodies, which are detached from spermatids and eliminated in mammals. However, the molecular and cellular mechanism underlying the removal of residual bodies remains largely unknown. Here, we demonstrate that during C. elegans spermatogenesis residual bodies are engulfed and degraded by gonadal sheath cells, a process that uses the same set of genes underlying apoptotic cell removal. The two partially redundant engulfment pathways that clear cell corpses also mediate phagocytosis of residual bodies, possibly by recognizing the ‘eat me’ signal phosphatidylserine exposed on the surface. The residual body-containing phagosome undergoes a maturation process involving sequential steps including dynamic coating with PtdIns(3)P and association of RAB small GTPases. The genetic hierarchy of residual body removal in hermaphrodites is similar to that of cell corpse clearance, but male residual body removal involves a distinct hierarchy, with differential use of the engulfment genes. Efficient removal of residual bodies regulates the number of spermatids and effective transfer of spermatids during male matings. Our results indicate that a similar molecular mechanism is employed for the removal of residual bodies and apoptotic cell corpses in C. elegans.
