Apoptosis and phosphatidylserine-mediated recognition during the take-over phase of the colonial life-cycle in the ascidian Botryllus schlosseri
Apoptosis and phosphatidylserine-mediated recognition during the take-over phase of the colonial life-cycle in the ascidian Botryllus schlosseri
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DOI：
10.1007/s00441-003-0738-9
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发表时间：
2003-06-01
影响因子：
3.6
通讯作者：
Ballarin, L
中科院分区：
文献类型：
--
作者：
Cima, F;Basso, G;Ballarin, L
海鞘类 Botryllus schlosseri 的群体经历反复的世代变化，其中成虫逐渐被吸收并被新的胚芽世代所取代。在这些被称为接管阶段的时期，程序性细胞死亡在动物组织中广泛发生，根据形态学分析将其归因于细胞凋亡。在本报告中，我们重新研究接管过程中的细胞死亡。结果证实了弥漫性细胞凋亡的发生，如染色质浓缩、TUNEL 反应阳性以及质膜外叶上磷脂酰丝氨酸的表达所证明。血细胞中也会发生细胞凋亡，衰老的血细胞会被循环中的专业吞噬细胞主动识别和吞噬。磷脂酰丝氨酸和 CD36（血小板反应蛋白受体的一个组成部分）都参与凋亡血细胞的识别，这促进了这样的观点：基本识别机制在整个脊索动物进化过程中都得到了很好的保守。
Colonies of the ascidian Botryllus schlosseri undergo recurrent generation changes in which adult zooids are gradually resorbed and replaced by new blastogenic generations. During these periods, known as take-over phases, programmed cell death, which, on the basis of morphological analysis is ascribed to apoptosis, occurs widely in zooid tissues. In the present report, we re-investigate cell death during the take-over process. Results confirm the occurrence of diffuse apoptosis, as evidenced by chromatin condensation, positivity to the TUNEL reaction and expression of phosphatidylserine on the outer leaflet of the plasma membrane. Apoptosis also occurs among haemocytes, and senescent blood cells are actively recognised and ingested by circulating professional phagocytes. Both phosphatidylserine and CD36, a component of the thrombospondin receptor, are involved in the recognition of apoptotic haemocytes, which fosters the idea that fundamental recognition mechanisms are well conserved throughout chordate evolution.