Kewalo Marine Laboratory, University of Hawaii, Honolulu, HI 96813, USA.
Integr Comp Biol. 2012 Dec;52(6):835-41. doi: 10.1093/icb/ics098. Epub 2012 Jul 4.
The key developmental role of the Hox cluster of genes was established prior to the last common ancestor of protostomes and deuterostomes and the subsequent evolution of this cluster has played a major role in the morphological diversity exhibited in extant bilaterians. Despite 20 years of research into cnidarian Hox genes, the nature of the cnidarian-bilaterian ancestral Hox cluster remains unclear. In an attempt to further elucidate this critical phylogenetic node, we have characterized the Hox cluster of the recently sequenced Acropora digitifera genome. The A. digitifera genome contains two anterior Hox genes (PG1 and PG2) linked to an Eve homeobox gene and an Anthox1A gene, which is thought to be either a posterior or posterior/central Hox gene. These data show that the Hox cluster of the cnidarian-bilaterian ancestor was more extensive than previously thought. The results are congruent with the existence of an ancient set of constraints on the Hox cluster and reinforce the importance of incorporating a wide range of animal species to reconstruct critical ancestral nodes.
Hox 基因簇在原口动物和后口动物的最后共同祖先之前就发挥了关键的发育作用，此后该基因簇的进化在现存的两侧对称动物的形态多样性中发挥了重要作用。尽管对刺胞动物 Hox 基因进行了 20 年的研究，但刺胞动物-两侧对称动物祖先 Hox 基因簇的性质仍不清楚。为了进一步阐明这一关键的系统发育节点，我们对最近测序的 Acropora digitifera 基因组中的 Hox 基因簇进行了特征描述。Acropora digitifera 基因组包含两个前 Hox 基因（PG1 和 PG2），与 Eve 同源盒基因和 Anthox1A 基因相连，后者被认为是后 Hox 基因或后/中央 Hox 基因。这些数据表明，刺胞动物-两侧对称动物祖先的 Hox 基因簇比以前想象的要广泛。这些结果与 Hox 基因簇存在一组古老的约束条件一致，并强调了纳入广泛的动物物种来重建关键祖先节点的重要性。
