Israel Oceanographic and Limnological Research, National Institute of Oceanography, Tel-Shikmona, PO Box 8030, Haifa 31080, Israel.
J Exp Biol. 2010 Feb 15;213(4):535-40. doi: 10.1242/jeb.039529.
Studies on allorecognition in the phylum Cnidaria have disclosed complex arrays of effector mechanisms, specificity and competency to distinguish precisely between self and non-self attributes, and have revealed the existence of allogeneic maturity. Here we studied allo-responses between young Stylophora pistillata colonies by following 517 allogeneic interactions between naturally settled kin aggregates and by establishing 417 forced allogeneic and autogeneic assays made of solitarily settled spat that were cut into two similar size subclones, of which one had been challenged allogeneically. Fused assays were exposed to a second allorecognition challenge, made of three allogeneic types. Whereas about half of the kin allogeneic interactions led to tissue fusions and chimera formations, none of the 83 non-sibling pair combinations were histocompatible. In contrast to previous results we recorded rejections between siblings at the age of less than two months. More challenging, we documented cases of fusions between interacting siblings at ages older than one-year-old partners, all differing from a previous study made on the same coral population more than a decade ago. Similar erratic histoincompatible responses were recorded in other pocilloporid species. We suggest that these results reflect reduced genetic heterogeneity caused by chronic anthropogenic impacts on shallow water coral populations where planulae originating from the same mother colony or from different mother colonies that are genetically related share increasing parts of their genomes. Offspring born to related parents may also reveal an increase in genomic homozygosity, and altogether impose erratic alloimmunity.
腔肠动物门中的同种异体识别研究揭示了复杂的效应机制、特异性和能力，可以精确区分自我和非自我属性，并发现了同种异体成熟的存在。在这里，我们通过跟踪自然定居的亲缘聚集物之间的 517 次同种异体相互作用，并建立了 417 次由单独定居的幼体切割而成的同种异体和自体测定来研究年轻的鹿角杯形珊瑚殖民地之间的同种异体反应，这些幼体被切割成两个相似大小的亚克隆，其中一个被同种异体挑战。融合测定物暴露于第二次同种异体识别挑战中，由三种同种异体类型组成。虽然大约一半的亲缘同种异体相互作用导致组织融合和嵌合体形成，但 83 个非兄弟姐妹对组合中没有一个是组织相容的。与之前的结果相反，我们记录了不到两个月大的兄弟姐妹之间的排斥反应。更具挑战性的是，我们记录了年龄超过一年的相互作用兄弟姐妹之间融合的案例，所有这些都与十多年前对同一珊瑚种群进行的先前研究不同。在其他滨珊瑚物种中也记录到了类似的不稳定同种异体不相容反应。我们认为，这些结果反映了由人为对浅海水域珊瑚种群的慢性影响引起的遗传异质性降低，在这些种群中，来自同一母珊瑚或遗传上相关的不同母珊瑚的浮游幼虫共享其基因组的越来越多的部分。相关父母所生的后代可能也会表现出基因组纯合度的增加，并且总体上会导致不稳定的同种异体免疫。
