Mortlock D P, Post L C, Innis J W
Department of Human Genetics, University of Michigan Medical School, Ann Arbor 48109-0618, USA.
Nat Genet. 1996 Jul;13(3):284-9. doi: 10.1038/ng0796-284.
Hypodactyly (Hd) is a semidominant mutation in mice that maps in a genetic interval overlapping the Hoxa cluster. The profound deficiency of digital arch structures in Hd/Hd mice is consistent with a defect in a gene activated late in limb morphogenesis. We have determined the structure of the Hoxa13 gene and describe a 50-base pair deletion in the first exon of the Hd allele that probably arose from unequal recombination or misalignment between triplet repeats. It is predicted that no Hoxa13 protein is made from Hd mRNA. The hypodactyly limb phenotype is similar to that of Hoxd13-deficient mice in sharing defects along multiple axes and alterations in cartilage maturation; however, the overall effects on digital arch formation are more severe in Hd/Hd mice. Our results confirm the critical role of AbdB-like Hox genes in the development of the autopod, and add to the spectrum of mutations involving triplet repeats.
少趾畸形（Hd）是小鼠中的一种半显性突变，其定位在与Hoxa基因簇重叠的遗传区间内。Hd/Hd小鼠中趾弓结构的严重缺陷与肢体形态发生后期激活的基因缺陷一致。我们已经确定了Hoxa13基因的结构，并描述了Hd等位基因第一个外显子中的一个50个碱基对的缺失，该缺失可能源于三联体重复序列之间的不等位重组或错配。据预测，Hd mRNA不会产生Hoxa13蛋白。少趾畸形的肢体表型与Hoxd13缺陷小鼠的表型相似，在多个轴向上都存在缺陷，软骨成熟也发生改变；然而，Hd/Hd小鼠对趾弓形成的总体影响更为严重。我们的结果证实了AbdB样Hox基因在 autopod发育中的关键作用，并增加了涉及三联体重复序列的突变谱。
