中法英MHC研究进展登《PloS Genetics 》

　　

人生的路上，选择一路同行的伴侣是我们一生中最重大的抉择。选择伴侣的标准因人而异，不外乎根据一些社会因素来选择，比如说，外貌、社会地位等。每个人都不能逃脱基因对我们的控制，伴侣选择看似与基因无关，其实，科学家掌握的证据告诉我们，选择伴侣与遗传因素也有关。最近，来自中国、法国、英国三个国家的科学家联手研究人类选择伴侣的遗传机制。相关的研究文章发表在最新的《PloS Genetics》上，科学家的研究证实，免疫特征会影响部分人类对伴侣的选择。

 

科学家发现，主要组织相容复合物（MHC）编码组织相性的基因群可影响人类伴侣的选择，MHC主要通过人体的气味来影响伴侣选择。先前的一些研究证实，人们在选择伴侣时，首选是MHC与自己不同的人，这一选择机制来源于杂交优势，下一代的MHC得到多样性的发展，可提高下一代的免疫能力。但是，其他的一些研究结果的理论与这一研究理论相左。

 

Raphaëlle Chaix, Chen Cao（中国科学院－马普学会计算生物学伙伴研究所，中科院与德国马普学会共建的研究院，隶属于中科院上海生命科学研究院） 和Peter Donnelly的研究把争论推上了高潮。三位科学家通过基因组扫描对非洲和欧洲的夫妇的人类白细胞抗原（HLA）进行分析。科学家们检验这些夫妻的MHC配型的相似程度，观察整个基因组上MHC在伴侣选择过程中所起的作用。研究小组将夫妻与随机配对的人群相比，检验他们的MHC是否相似性高，或是低。

 

结果发现，与随机配对的人群相比，非洲的夫妻MHC相似性不高也不低，这表明，可能在选择伴侣的过程中还受社会因素的影响。而另一方面，在美国，欧洲裔的大部分美国夫妻MHC相似度相当低，尤其是从整个基因组来考量，差异更明显，这就表明，在有些人群中，伴侣选择受MHC的影响。研究者下一步还将探索生物学特征在伴侣选择过程中的作用。

 

主要组织相容性复合体(major histocompatibility complex，MHC)系编码主要组织相性抗原的基因群。其基因产物不但参与移植排斥反应和 T 细胞的分化发育，而且在免疫应答的启动和免疫调节中发挥重要作用。

 

原文摘要：Is Mate Choice in Humans MHC-Dependent?

doi:10.1371/journal.pgen.1000184

 

【Abstract】

In several species, including rodents and fish, it has been shown that the Major Histocompatibility Complex (MHC) influences mating preferences and, in some cases, that this may be mediated by preferences based on body odour. In humans, the picture has been less clear. Several studies have reported a tendency for humans to prefer MHC-dissimilar mates, a sexual selection that would favour the production of MHC-heterozygous offspring, who would be more resistant to pathogens, but these results are unsupported by other studies. Here, we report analyses of genome-wide genotype data (from the HapMap II dataset) and HLA types in African and European American couples to test whether humans tend to choose MHC-dissimilar mates. In order to distinguish MHC-specific effects from genome-wide effects, the pattern of similarity in the MHC region is compared to the pattern in the rest of the genome. African spouses show no significant pattern of similarity/dissimilarity across the MHC region (relatedness coefficient, R = 0.015, p = 0.23), whereas across the genome, they are more similar than random pairs of individuals (genome-wide R = 0.00185, p<10⁻³). We discuss several explanations for these observations, including demographic effects. On the other hand, the sampled European American couples are significantly more MHC-dissimilar than random pairs of individuals (R = −0.043, p = 0.015), and this pattern of dissimilarity is extreme when compared to the rest of the genome, both globally (genome-wide R = −0.00016, p = 0.739) and when broken into windows having the same length and recombination rate as the MHC (only nine genomic regions exhibit a higher level of genetic dissimilarity between spouses than does the MHC). This study thus supports the hypothesis that the MHC influences mate choice in some human populations.

 

（生物通 张欢）