Studies on the mechanism of allorecognition in botryllid ascidians

1.在几种海鞘类中，它们的同种识别方式略有不同。这种异体识别方式的多样性是由于参与同种异体排斥反应的血细胞类型不同，同种血细胞的功能不同，以及菌落中分布的同种异体识别部位不同所致。2.通过对一种复合柱状海鞘和几种海鞘海鞘的同种异体排斥反应的比较研究，明确了桑囊细胞主要参与的同种异体排斥反应是海鞘海鞘的mpst原始性反应。此外，从rDNA分析获得的蝶形目昆虫的系统发育与从同种异体识别方式推测的系统发育几乎相同。对同种异体排斥反应时血细胞中特异性或特异性增加的mRNAs进行了研究，获得了23个cDNAs。其中有6个基因与哺乳动物免疫相关基因相似。此外，其中3个与哺乳动物MHCIII连锁的热休克蛋白70(HSP70)有很高的相似性。这三个蛋白中有两个与已知的志贺杆菌HSP70.1和HSP70.2蛋白相同，但最后一个蛋白是一个新的热休克蛋白，其基因全长约3kb。该基因全长900个碱基，与哺乳动物MHCIII连锁的HSP70序列有77%的相似性。该蛋白的氨基酸序列与哺乳动物MHCIII连锁的HSP70有很高的相似性(83%)。现在，我们正在研究该蛋白在同种异体排斥反应中的作用以及在同种异体排斥反应中在克隆中的分布。

1. Among several species of botryllid ascidians, the manners of allorecognition of those species are slightly different from each other. This variety of the allorecognition manners is caused by the difference of blood cell types participating in allorejection, and the difference of function in the same type blood cells, as well as allorecognition sites distributed in the colony. 2.From the comparative study of allorejection reaction among a compound styelid ascidian and some botryllid ascidians, it was cleared that the allorejection in which morula cells mainly participate is the mpst primitive reaction in botryllids. Furthermore, the phylogeny of botryllids obtained from rDNA analysis is almost the same as that speculated from the variety of allorecognition manners.3. The specific or specifically increasing mRNAs in the blood cells at the allorejection reaction were investigated, and 23 cDNA were gained from this experiment. Six of them were similar to the genes related with immunity of mammals. Furthermore, three of them showed high similarity to the heat shock protein 70 (HSP 70) linked with MHCIII of mammals. Two of these three were the same as the already known proteins in B.schlosseri, HSP 70.1 and HSP 70.2, respectively, but the last one was a new heat shock protein of which gene is about 3 kb in length. The sequence of 900 bases of this gene has been cleared, and that sequence shows 77%similarity to that of HSP 70 linked with MHCIII of mammals. The amino acid sequence of this protein also shows high similarity (83 %) to that of HSP 70 linked with MHCIII of mammals. Now, we are investigating on the role of this protein in the allorejection and distribution in the colony during allorejection.