Origin and radiation of the house mouse: Clues from nuclear genes
Origin and radiation of the house mouse: Clues from nuclear genes
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DOI：
10.1046/j.1420-9101.1996.9050519.x
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发表时间：
1996-09-01
影响因子：
2.1
通讯作者：
Bonhomme, F
中科院分区：
文献类型：
--
作者：
Din, W;Anand, R;Bonhomme, F
虽然对分布区外围的多型种小家鼠的遗传结构有很多了解，但该物种的起源和扩散中心仍然未知。为了调查发生在其范围的中心部分的遗传细分的量，我们分析了来自伊朗，巴基斯坦，北方和印度南部的四个新的小鼠样本的遗传变异，使用35个常染色体蛋白位点和限制性片段长度多态性的免疫系统的V β基因复合物的三个基因。然后比较的变化，发现在亚种占据的物种范围的周边地区。来自印度次大陆北方部分的两个样品显示出比来自任何其他地区的样品更杂合。它们还包含了存在于物种范围边缘的分化亚种中的大多数等位基因。Nei的遗传距离和析因分析的对应关系的等位基因组成的每个样本的邻居加入分析都把巴基斯坦和印度的人口在一个遗传学和遗传中心的位置相比，周边亚种。这些结果表明，在这个地理中心区域的人口保留了大部分的祖先多态性，这反过来又表明，印度次大陆可能是该物种的摇篮。还讨论了在整个物种范围内的各种群体之间的遗传关系的性质和它们形成初期环种的可能性。我们的研究结果与经典的地理分化模型一致，在异地遗传分化被认为是亚种形成的主要原因，最终可能导致部分生殖隔离的二次接触。
Although quite a lot is known about the genetic structure of the polytypic species Mus musculus at the periphery of its range, the centre of origin and dispersion of the species remains unknown. To investigate the amount of genetic subdivision that occurs in the central parts of its range, we analysed the genetic variation in four new samples of mice coming from Iran, Pakistan, northern and southern India using 35 autosomal protein loci and restriction fragment length polymorphisms of three genes of the V beta gene complex of the immune system. The variation was then compared with that found in the subspecies occupying the peripheral regions of the species range. The two samples from the northern part of the Indian subcontinent were shown to be more heterozygous than the samples from any of the other regions. They also contain the majority of the alleles that exist in the differentiated subspecies at the periphery of the species range. A neighbour-joining analysis on Nei's genetic distances and a factorial analysis of correspondences on the allelic composition of each sample both place the Pakistani and Indian populations in a phylogenetically and genetically central position compared to the peripheral subspecies. These results suggest that the populations in this geographically central area have retained most of the ancestral polymorphisms, which in turn indicates that the Indian subcontinent is probably the cradle of the species. The nature of the genetic relationships between the various populations throughout the species range and the possibility that they form an incipient ring species are also discussed. Our results are in agreement with the classical model of geographic differentiation where genetic divergence in allopatry is considered to be the prime cause of subspecies formation that may eventually lead to partial reproductive isolation on secondary contact.