Chai C K
J Hered. 1981 Jul-Aug;72(4):234-7. doi: 10.1093/oxfordjournals.jhered.a109486.
Dactylaplasia, characterized by the absence of phalangeal bones in the middle digits of each foot, resulted from a mutation that occurred in the SM7B/SM inbred strain of mice. Breeding tests revealed the mutant gene is an autosomal dominant that is homozygous lethal. Further investigation by outcrossing with a number of inbred strains showed that the manifestation of the mutant gene is controlled by another locus. At this locus are found two alleles: one, a dominant inhibiting dactylaplasia gene expression; the other, a recessive allowing the expression of the mutant gene. In each of the tested inbred strains, one or the other allele is present at this locus. We propose Dac as a symbol for the mutant gene, and mdac for the locus controlling the Dac expression. Mouse dactylaphasia closely resembles split hand/foot in man and in monkeys in gross morphology and mode of inheritance. The significance of the present findings explainable by a two-locus model is discussed relative to irregular mode of inheritance of certain other congenital defects, and also relative to the maintenance of genetic loads in populations.
并指畸形表现为每只脚中间趾骨缺失，是由小鼠SM7B/SM近交系中发生的一种突变引起的。育种试验表明，突变基因是常染色体显性基因，纯合致死。通过与多个近交系杂交进行的进一步研究表明，突变基因的表现受另一个基因座控制。在这个基因座上发现了两个等位基因：一个是显性抑制并指畸形基因表达的；另一个是隐性允许突变基因表达的。在每个测试的近交系中，这个基因座上存在其中一个或另一个等位基因。我们提议用Dac作为突变基因的符号，用mdac作为控制Dac表达的基因座的符号。小鼠并指畸形在总体形态和遗传方式上与人类和猴子的裂手/裂足非常相似。本文讨论了用双基因座模型解释的当前研究结果的意义，涉及某些其他先天性缺陷的不规则遗传方式，以及种群中遗传负荷的维持。
