Rinkevich B, Weissman I L, De Tomaso A W
National Institute of Oceanography, Haifa, Israel.
Biol Bull. 1998 Oct;195(2):98-106. doi: 10.2307/1542816.
The colonial urochordate Botryllus schlosseri undergoes a genetically defined, natural transplantation reaction that is controlled by a single Mendelian locus (called the Fu/HC). This Fu/HC-based allorecognition system is initiated when peripheral elements of the vasculature interact on the edges of two asexually expanding colonies. To better understand the spatial organization of the cellular elements responsible for Fu/HC-based allorecognition, we bypassed the normal site of interaction (the ampullae) and experimentally transplanted zooids between Fu/HC-noncompatible Botryllus schlosseri pairs. The results show that (1) instead of the expected rejections (tissue necroses) that develop after natural contacts between peripheral blood vessels, the transplanted organs are morphologically eliminated within a few days in conjunction with the normal blastogenic cycle; and (2) donor-recipient chimerism is established after complete morphological elimination of transplanted tissues. These results suggest that Fu/HC-based allorecognition responses in Botryllus schlosseri occur exclusively at the ampullae and that once cells have crossed this barrier, they are able to survive and proliferate in the new host colony.
群体海鞘Botryllus schlosseri会经历一种由基因决定的自然移植反应，该反应由单个孟德尔位点（称为Fu/HC）控制。当脉管系统的外周成分在两个无性扩张群体的边缘相互作用时，基于Fu/HC的同种异体识别系统就会启动。为了更好地理解负责基于Fu/HC的同种异体识别的细胞成分的空间组织，我们绕过了正常的相互作用位点（壶腹），并在Fu/HC不兼容的Botryllus schlosseri配对之间进行了实验性的游动孢子移植。结果表明：（1）与外周血管自然接触后预期出现的排斥反应（组织坏死）不同，移植器官在几天内随着正常的芽殖周期在形态上被清除；（2）在移植组织完全形态清除后建立了供体-受体嵌合体。这些结果表明，Botryllus schlosseri中基于Fu/HC的同种异体识别反应仅发生在壶腹处，并且一旦细胞越过这一屏障，它们就能在新的宿主群体中存活并增殖。
