Kuraku Shigehiro, Meyer Axel
Lehrstuhl fur Zoologie und Evolutionsbiologie, Department of Biology, University of Konstanz, Germany.
Int J Dev Biol. 2009;53(5-6):765-73. doi: 10.1387/ijdb.072533km.
Hox genes are known to specify spatial identities along the anterior-posterior axis during embryogenesis. In vertebrates and most other deuterostomes, they are arranged in sets of uninterrupted clusters on chromosomes, and are in most cases expressed in a "colinear" fashion, in which genes closer to the 3-end of the Hox clusters are expressed earlier and more anteriorly and genes close to the 5-end of the clusters later and more posteriorly. In this review, we summarize the current understanding of how Hox gene clusters have been modified from basal lineages of deuterostomes to diverse taxa of vertebrates. Our parsimony reconstruction of Hox cluster architecture at various stages of vertebrate evolution highlights that the variation in Hox cluster structures among jawed vertebrates is mostly due to secondary lineage-specific gene losses and an additional genome duplication that occurred in the actinopterygian stem lineage, the teleost-specific genome duplication (TSGD).
已知Hox基因在胚胎发育过程中沿前后轴指定空间身份。在脊椎动物和大多数其他后口动物中，它们以不间断的簇集形式排列在染色体上，并且在大多数情况下以“共线性”方式表达，即靠近Hox簇3'端的基因更早且更靠前表达，而靠近簇5'端的基因则更晚且更靠后表达。在这篇综述中，我们总结了目前对Hox基因簇如何从后口动物的基础谱系演变为脊椎动物的不同分类群的理解。我们对脊椎动物进化各个阶段Hox簇结构的简约重建突出表明，有颌脊椎动物中Hox簇结构的变化主要是由于次生谱系特异性基因丢失以及在辐鳍鱼干群谱系中发生的一次额外的基因组复制，即硬骨鱼特异性基因组复制（TSGD）。
