Letts V A, Schork N J, Copp A J, Bernfield M, Frankel W N
Jackson Laboratory, Bar Harbor, Maine 04609, USA.
Genomics. 1995 Oct 10;29(3):719-24. doi: 10.1006/geno.1995.9946.
The major gene for neural tube defects, ct, in the curly-tail (CT) mouse strain was mapped previously to mouse chromosome 4 by combining linkage data from several backcrosses. The penetrance of the neural tube trait, already incomplete in the CT strain, was further reduced in several of these backcrosses, suggesting the existence of recessive modifiers or strain-specific susceptibility alleles. Here we describe the mapping of a curly-tail modifier locus, mct1, to chromosome 17 in moderate and low penetrance crosses of CT with BALB/cByJ and Mus spretus. No effect of mct1 was seen in a higher penetrance cross with the BXD-8/Ty strain, confirming that ct is the major gene in the model. Homozygosity at both ct and mct1 loci was sufficient to account for all of the affected individuals in the BALB/cByJ cross and most of the affected individuals in the M. spretus cross and was the preferred model overall. No evidence was found for epistatic interaction between ct and mct1.
神经管缺陷的主要基因ct，存在于卷尾（CT）小鼠品系中，先前通过合并来自多个回交的连锁数据，将其定位到小鼠4号染色体上。神经管性状的外显率在CT品系中本就不完全，在其中几个回交中进一步降低，这表明存在隐性修饰基因或品系特异性易感等位基因。在此，我们描述了在CT与BALB/cByJ和西班牙小家鼠的中度和低度外显率杂交中，一个卷尾修饰基因座mct1被定位到17号染色体上。在与BXD - 8/Ty品系的高外显率杂交中未观察到mct1的效应，证实ct是该模型中的主要基因。在BALB/cByJ杂交中，ct和mct1两个基因座的纯合性足以解释所有受影响个体，在西班牙小家鼠杂交中足以解释大多数受影响个体，并且总体上是首选模型。未发现ct和mct1之间存在上位性相互作用的证据。
