孩子遺傳了父母的基因,，但孩子又與父母有所不同,，這是因為父母的基因在遺傳給孩子時會經過重組等變化，一項最新研究顯示,，在這個變化過程中,，父母遺傳物質的作用并不相同。
英國《自然》雜志10月28日刊登研究報告說,，冰島基因研究機構deCODE的研究人員分析了1.5萬個家庭中父母與孩子的基因,，發(fā)現了這一現象。
報告說,，每個人的基因組中都有兩套遺傳物質,，一套來自父親，另一套來自母親,。遺傳重組指的是,，男性或女性體內在形成精子或卵子時，這兩套遺傳物質會分開,，其中一些部分會交叉重組,，形成一套新的遺傳物質，不論精子還是卵子,，都只含有這一套經過重組變化后的遺傳物質,。
當精子和卵子結合時，它們各自攜帶的一套遺傳物質又會連接到一起并進行重組,，從而構成孩子的基因組,。但本次研究發(fā)現,，在這一過程中，父母遺傳物質的作用并不相同,，父親一方的遺傳物質更多地在基因內部發(fā)生變化，產生新的基因,，而母親一方的遺傳物質更多的是基因之間的位置發(fā)生變化,。
領導研究的卡里·斯特凡松告訴新華社記者，父母雙方遺傳物質不僅重組的方式有側重,，重組的程度也不一樣,。卵子中遺傳物質重組的程度高于精子。由于遺傳重組是產生基因差異并隨之導致人類多樣性的重要原因,，從遺傳重組的角度看,，女性在推動人類多樣性方面的貢獻要大于男性。
不過,，導致基因差異和人類多樣性的原因除遺傳重組外,，還有基因突變等，而研究顯示男性精子的基因突變程度要高于女性的卵子,。斯特凡松因此表示：“很難說男性和女性哪一方在人類多樣性上貢獻更大,，但可以看出男性和女性在以不同的方式推動人類多樣性的發(fā)展。”（生物谷Bioon.com）
生物谷推薦英文摘要：
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.
