Cino-Japanese cooperative research on surveying genetic variants in Chinese wild mice and developing their inbred strains

我们称它们为肌肉亚种。在这些区域，经常观察到p-单倍型血红蛋白（Hbb）。在中国长江以南地区和东南亚如菲律宾、台湾和印度尼西亚，有castaneus亚种，其中包括至少两种castaneus小家鼠。在这些区域，d-单倍型Hbb占主导地位。根据分子遗传学分析，这两个亚种群之间的遗传差异估计大约有100万年（Yonekawa et al, 1981）。最近我们发现了一种新的Hbb单倍型w1，它分布在中国西北地区，频率较高（kawashima et al, 1991）。本研究分析了w1单倍型b1-w1和b2-w1两个血红蛋白基因cdna的核苷酸序列，并与w1单倍型b1-d和b2-d以及p单倍型b1-p和b2-p的核苷酸序列进行了比较。b1-d和b1-p序列非常相似，b2-w1和b2-p序列也非常相似。另一方面，在b1-d和b1-w1之间以及b2-d和b2-w1之间检测到几个核苷酸替换。这些发现提示，在小家鼠亚种分化后，d-单倍型和w1-单倍型Hbb染色体之间可能发生了重组，产生了带有b1-d和b2-w1基因的p-单倍型。因此，p-单倍型可能是一种亚种间重组。本项目携带家鼠亚种的进一步地理调查表明，Hbb在俄罗斯东部即中国北方北部地区存在d单倍型，提示除中国南方地区外，该地区可能还存在castaneus亚种群。可以假设两种可能性：(1)在古代，野生小鼠的castaneus亚种群曾从东南亚向俄罗斯东部扩散分布。后来，肌肉亚种群从西亚入侵到麻蝇分布的中部地区。(2)近期由东南亚货船运至俄罗斯东部的鼠属castaneus亚种群。为了得到更可信的结论，对亚洲小鼠dna的精确分析是必要的。少

In east Asia including mainland China north of Yangtze River, Korea and Japan, a house mouse subspecies, Mus musculis musculus, and some other genetically close ones inhabit. We call them musculus subspecies group. In those regions, p-haplotyoe beta-hemoglobin (Hbb) is frequently observed. In China south of Yangtze River and southeast Asia such as the Philippines, Taiwan and Indonesia, castaneus subspecies group of mice which includes as least two types of Mus musculus castaneus inhabit. In these regions, d-haplotype Hbb is predominant. Genetic divergence between those two subspecies groups has been estimated roughly one million yeare based on molecular genetic analyzes (Yonekawa et al, 1981). Recently we have found a novel Hbb haplotype w1 which is distributed in northwestern region of China with the higher frequency (kawashima et al, 1991). In this study nucleotide siquences of cDNAs in the two hamoglobin genes, b1-w1 and b2-w1, of w1 haplotype were analyzed and compared with those o … More f d haplotype, b1-d and b2-d, and those of p-haplotype, b1-p and b2-p. The sequences of b1-d and b1-p were quite similar, and those of b2-w1 and b2-p as well. On the other hand, several nucleotide substitutions were detected between b1-d and b1-w1 and also between b2-d and b2-w1. These findings suggest a possibility that after differentiation of Mus musculus subspecies, a recombination occurred between d-haplotype and w1-haplotype Hbb chromosomes, which produced p-haplotype with b1-d and b2-w1 genes. Thus, p-haplotype coule be an inter-subspecies recombinant.Further geographical survey of house mouse subspecies carried in the oresent project demonstarated the oresence of d-haplotype of Hbb in east Russia, that is, north of northern China, which suggests possible distribution of castaneus subspecies group in that region in addition to southern China. Twopossibilities could be assumed : (1) In ancient time, castaneus subspecies group of wild mice had once spread their distribution from southeast Asia up to east Russia. Later, musculus subspecies group invaded into the central region of castaneus distribution from west Asia. (2) To east Russia, castaneus subspecies group of mice were recently transported by cargo boats from southeast Asia. Precise analysis of in Asian mouse DNAs is necessary to obtain the more plausible conclusion. Less