a Graduate School of Bioresource Sciences, Nihon University, Fujisawa, Kanagawa 252-0880, Japan.
b Museum of Vertebrate Zoology, University of California, 3101 Valley Life Sciences Building, Berkeley, CA 94720-3160, USA.
Genome. 2018 Mar;61(3):195-200. doi: 10.1139/gen-2017-0139. Epub 2018 Feb 5.
It has been thought that the Japanese house mouse carries the A allele at the agouti locus causing light-colored bellies, but they do not always show this coloration. Thus, the presence of the A allele seems to be doubtful in them. To ascertain whether the A allele is present, a two-pronged approach was used. First, we compared lengths of DNA fragments obtained from three PCRs conducted on them to the known fragment sizes generated from mouse strains exhibiting homozygosities of either a/a, A/A, or A/A. PCR I, PCR II, and PCR III amplify only in the A and A alleles, the a and A alleles, and the a allele, respectively, and we detected amplifications in strains with A/A and A/A by PCR I, in those with a/a and the Japanese house mouse by PCR II, and in those with a/a by PCR III. Second, we sequenced the exon 1A region of the agouti gene and obtained sequences corresponding to the above strains and the Japanese house mouse, but their sequences were similar to those of the a allele. We concluded that their agouti allele is not identical to the A allele and seems to be a novel type similar to the a allele.
人们曾认为日本小家鼠携带引起浅色腹部的 agouti 基因座的 A 等位基因，但它们并不总是表现出这种颜色。因此，A 等位基因在它们身上似乎存在疑问。为了确定 A 等位基因是否存在，采用了双管齐下的方法。首先，我们将从对它们进行的三次 PCR 获得的 DNA 片段长度与来自表现出 a/a、A/A 或 A/A 纯合性的鼠种的已知片段大小进行了比较。PCR I、PCR II 和 PCR III 分别仅在 A 和 A 等位基因、a 和 A 等位基因以及 a 等位基因中扩增，我们通过 PCR I 在具有 A/A 和 A/A 的品系中检测到扩增，通过 PCR II 在具有 a/a 和日本小家鼠的品系中检测到扩增，通过 PCR III 在具有 a/a 的品系中检测到扩增。其次，我们对 agouti 基因的外显子 1A 区域进行了测序，并获得了与上述品系和日本小家鼠相对应的序列，但它们的序列与 a 等位基因的序列相似。我们得出结论，它们的 agouti 等位基因与 A 等位基因不同，似乎是一种类似于 a 等位基因的新型等位基因。
