Wedekind C, Füri S
Abteilung Verhaltensökologie, Universität Bern, Hinterkappelen, Switzerland.
Proc Biol Sci. 1997 Oct 22;264(1387):1471-9. doi: 10.1098/rspb.1997.0204.
The major histocompatibility complex (MHC) is an immunologically important group of genes that appears to be under natural as well as sexual selection. Several hypotheses suggest that certain MHC-allele combinations (usually heterozygous ones) are superior under selective pressure by pathogens. This could influence mate choice in a way that preferences function to create MHC-heterozygous offspring, or that they function to create specific allele combinations that are beneficial under the current environmental conditions through their complementary or epistatic effects. To test these hypotheses, we asked 121 men and women to score the odours of six T-shirts, worn by two women and four men. Their scorings of pleasantness correlated negatively with the degree of MHC similarity between smeller and T-shirt-wearer in men and women who were not using the contraceptive pill (but not in Pill-users). Depending on the T-shirt-wearer, the amount of variance in the scorings of odour pleasantness that was explained by the degree of MHC similarity (r2) varied between nearly 0 and 23%. There was no apparent effect of gender in this correlation: the highest r2 was actually reached with one of the male odours sniffed by male smellers. Men and women who were reminded of their own mate/ex-mate when sniffing a T-shirt had significantly fewer MHC-alleles in common with this T-shirt-wearer than expected by chance. This suggests that the MHC or linked genes influence human mate choice. We found no significant effect when we tested for an influence of the MHC on odour preferences after the degree of similarity between T-shirt-wearer and smeller was statistically controlled for. This suggests that in our study populations the MHC influences body odour preferences mainly, if not exclusively, by the degree of similarity or dissimilarity. The observed preferences would increase heterozygosity in the progeny. They do not seem to aim for more specific MHC combinations.
主要组织相容性复合体（MHC）是一组在免疫学上很重要的基因，似乎受到自然选择和性选择的影响。有几种假说认为，某些MHC等位基因组合（通常是杂合子）在病原体的选择压力下具有优势。这可能会以某种方式影响配偶选择，即偏好的作用是产生MHC杂合子后代，或者偏好的作用是通过互补或上位效应产生在当前环境条件下有益的特定等位基因组合。为了检验这些假说，我们让121名男性和女性对两件女性和四名男性所穿的六件T恤的气味进行评分。在未服用避孕药的男性和女性中（服用避孕药的人则不然），他们对气味愉悦度的评分与闻气味者和T恤穿着者之间的MHC相似程度呈负相关。根据T恤穿着者的不同，由MHC相似程度所解释的气味愉悦度评分的方差量（r2）在近0到23%之间变化。在这种相关性中没有明显的性别效应：实际上，男性闻男性气味之一时r2最高。在闻T恤时想起自己配偶/前配偶的男性和女性与该T恤穿着者共有的MHC等位基因明显少于随机预期。这表明MHC或相关基因会影响人类的配偶选择。在对T恤穿着者和闻气味者之间的相似程度进行统计控制后，我们测试MHC对气味偏好的影响时没有发现显著影响。这表明在我们的研究人群中，MHC主要（如果不是唯一的话）通过相似或不相似程度来影响体味偏好。观察到的偏好会增加后代的杂合性。它们似乎并不是为了形成更特定的MHC组合。
