Abstract:
Despite decades of research, surprisingly little is known about the mechanism(s) by which an individual\'s genotype is encoded in odour. Many studies have focused on the role of the major histocompatibility complex (MHC) owing to its importance for survival and mate choice. However, the salience of MHC-mediated odours compared to chemicals influenced by the rest of the genome remains unclear, especially in wild populations where it is challenging to quantify and control for the effects of the genomic background. We addressed this issue in Antarctic fur seals by analysing skin swabs together with full-length MHC DQB II exon 2 sequences and data from 41 genome-wide distributed microsatellites. We did not find any effects of MHC relatedness on chemical similarity and there was also no relationship between MHC heterozygosity and chemical diversity. However, multilocus heterozygosity showed a significant positive association with chemical diversity, even after controlling for MHC heterozygosity. Our results appear to rule out a dominant role of the MHC in the chemical encoding of genetic information in a wild vertebrate population and highlight the need for genome-wide approaches to elucidate the mechanism(s) and specific genes underlying genotype-odour associations.
摘要:
尽管经过几十年的研究,令人惊讶的是,人们对个体基因型在气味中编码的机制知之甚少。由于主要组织相容性复合体(MHC)对生存和配偶选择的重要性,许多研究都集中在其作用上。然而,与受基因组其余部分影响的化学物质相比,MHC介导的气味的显著性尚不清楚,尤其是在野生种群中,量化和控制基因组背景的影响具有挑战性。我们通过分析皮肤拭子以及全长MHCDQBII外显子2序列和来自41个全基因组分布式微卫星的数据,解决了南极海豹的这个问题。我们没有发现MHC相关性对化学相似性的任何影响,并且MHC杂合性与化学多样性之间也没有关系。然而,多位点杂合性与化学多样性呈显著正相关,即使在控制MHC杂合性之后。我们的结果似乎排除了MHC在野生脊椎动物种群遗传信息的化学编码中的主导作用,并强调了需要全基因组方法来阐明基因型-气味关联的机制和特定基因。