孩子遗传了父母的基因，但孩子又与父母有所不同，这是因为父母的基因在遗传给孩子时会经过重组等变化，一项最新研究显示，在这个变化过程中，父母遗传物质的作用并不相同。
英国《自然》杂志10月28日刊登研究报告说，冰岛基因研究机构deCODE的研究人员分析了1.5万个家庭中父母与孩子的基因，发现了这一现象。
报告说，每个人的基因组中都有两套遗传物质，一套来自父亲，另一套来自母亲。遗传重组指的是，男性或女性体内在形成精子或卵子时，这两套遗传物质会分开，其中一些部分会交叉重组，形成一套新的遗传物质，不论精子还是卵子，都只含有这一套经过重组变化后的遗传物质。
当精子和卵子结合时，它们各自携带的一套遗传物质又会连接到一起并进行重组，从而构成孩子的基因组。但本次研究发现，在这一过程中，父母遗传物质的作用并不相同，父亲一方的遗传物质更多地在基因内部发生变化，产生新的基因，而母亲一方的遗传物质更多的是基因之间的位置发生变化。
领导研究的卡里·斯特凡松告诉新华社记者，父母双方遗传物质不仅重组的方式有侧重，重组的程度也不一样。卵子中遗传物质重组的程度高于精子。由于遗传重组是产生基因差异并随之导致人类多样性的重要原因，从遗传重组的角度看，女性在推动人类多样性方面的贡献要大于男性。
不过，导致基因差异和人类多样性的原因除遗传重组外，还有基因突变等，而研究显示男性精子的基因突变程度要高于女性的卵子。斯特凡松因此表示：“很难说男性和女性哪一方在人类多样性上贡献更大，但可以看出男性和女性在以不同的方式推动人类多样性的发展。”（生物谷Bioon.com）
生物谷推荐英文摘要：
Nature doi:10.1038/nature09525
Fine-scale recombination rate differences between sexes, populations and individuals
Augustine Kong, Gudmar Thorleifsson, Daniel F. Gudbjartsson, Gisli Masson, Asgeir Sigurdsson, Aslaug Jonasdottir, G. Bragi Walters, Adalbjorg Jonasdottir, Arnaldur Gylfason, Kari Th. Kristinsson, Sigurjon A. Gudjonsson, Michael L. Frigge, Agnar Helgason, Unnur Thorsteinsdottir & Kari Stefansson
Meiotic recombinations contribute to genetic diversity by yielding new combinations of alleles. Recently, high-resolution recombination maps were inferred from high-density single-nucleotide polymorphism (SNP) data using linkage disequilibrium (LD) patterns that capture historical recombination events1, 2. The use of these maps has been demonstrated by the identification of recombination hotspots2 and associated motifs3, and the discovery that the PRDM9 gene affects the proportion of recombinations occurring at hotspots4, 5, 6. However, these maps provide no information about individual or sex differences. Moreover, locus-specific demographic factors like natural selection7 can bias LD-based estimates of recombination rate. Existing genetic maps based on family data avoid these shortcomings8, but their resolution is limited by relatively few meioses and a low density of markers. Here we used genome-wide SNP data from 15,257 parent–offspring pairs to construct the first recombination maps based on directly observed recombinations with a resolution that is effective down to 10 kilobases (kb). Comparing male and female maps reveals that about 15% of hotspots in one sex are specific to that sex. Although male recombinations result in more shuffling of exons within genes, female recombinations generate more new combinations of nearby genes. We discover novel associations between recombination characteristics of individuals and variants in the PRDM9 gene and we identify new recombination hotspots. Comparisons of our maps with two LD-based maps inferred from data of HapMap populations of Utah residents with ancestry from northern and western Europe (CEU) and Yoruba in Ibadan, Nigeria (YRI) reveal population differences previously masked by noise and map differences at regions previously described as targets of natural selection.
