Stet René J M, Kruiswijk Corine P, Dixon Brian
Cell Biology and Immunology Group, Wageningen Institute of Animal Sciences, Wageningen University, Wageningen, The Netherlands.
Crit Rev Immunol. 2003;23(5-6):441-71. doi: 10.1615/critrevimmunol.v23.i56.50.
It has become increasingly clear over the course of the past decade that the immune system genes of teleosts and tetrapods are plainly derived from common ancestral genes. The last 5 years, however, have also made it abundantly clear that in the teleost genome some of these genes are organized in a manner very different from that seen in mammals. These differences are probably the result of differences in life history traits, such as fecundancy, within each group of species when faced with an evolutionary fork in the road shortly after their divergence from each other. One group, the tetrapods, including mammals, chose a highly organized linked major histocompatibility complex, while in teleosts the major histocompatibility genes remained unlinked. In this review we will discuss the structural and functional implications of this different organization, particularly for major histocompatibility genes, but drawing on the current knowledge of some other genes for further support for the hypothesis that each group took a different road, one more traveled and one less taken.
在过去十年中，越来越明显的是，硬骨鱼和四足动物的免疫系统基因显然源自共同的祖先基因。然而，在过去五年中也非常清楚地表明，在硬骨鱼基因组中，其中一些基因的组织方式与哺乳动物中所见的方式非常不同。这些差异可能是由于每组物种在彼此分化后不久面临进化岔路口时，其生活史特征（如繁殖力）不同所致。其中一组，包括哺乳动物在内的四足动物，选择了高度组织化的连锁主要组织相容性复合体，而在硬骨鱼中，主要组织相容性基因仍然未连锁。在这篇综述中，我们将讨论这种不同组织方式的结构和功能影响，特别是对于主要组织相容性基因，但也借鉴一些其他基因的现有知识，以进一步支持这一假设，即每组走了不同的道路，一条走得多些，一条走得少些。
