National Research Center Frontiers in Genetics, Department of Zoology and Animal Biology, University of Geneva, Sciences III, 1211 Geneva 4, Switzerland.
Nature. 2010 Mar 4;464(7285):99-103. doi: 10.1038/nature08789.
Hox genes are central to the specification of structures along the anterior-posterior body axis, and modifications in their expression have paralleled the emergence of diversity in vertebrate body plans. Here we describe the genomic organization of Hox clusters in different reptiles and show that squamates have accumulated unusually large numbers of transposable elements at these loci, reflecting extensive genomic rearrangements of coding and non-coding regulatory regions. Comparative expression analyses between two species showing different axial skeletons, the corn snake and the whiptail lizard, revealed major alterations in Hox13 and Hox10 expression features during snake somitogenesis, in line with the expansion of both caudal and thoracic regions. Variations in both protein sequences and regulatory modalities of posterior Hox genes suggest how this genetic system has dealt with its intrinsic collinear constraint to accompany the substantial morphological radiation observed in this group.
Hox 基因对于沿身体前后轴的结构的特化至关重要，它们的表达的改变与脊椎动物身体模式的多样性的出现相平行。在这里，我们描述了不同爬行动物的 Hox 簇的基因组组织，并表明蜥蜴类在这些位置积累了异常多的转座元件，反映了编码和非编码调控区域的广泛基因组重排。对具有不同轴骨的两个物种（玉米蛇和鞭尾蜥蜴）进行的比较表达分析表明，在蛇体节发生过程中，Hox13 和 Hox10 的表达特征发生了重大改变，与尾部和胸部区域的扩张一致。后 Hox 基因的蛋白质序列和调控方式的变化表明，这种遗传系统如何应对其内在的共线性约束，以伴随该组中观察到的大量形态辐射。
