Microbial Phylogeography, Department of Microbiology, Environmental Research Institute, University College Cork, Cork, Ireland.
Heredity (Edinb). 2012 Apr;108(4):403-9. doi: 10.1038/hdy.2011.87. Epub 2011 Sep 21.
Major histocompatibility complex (MHC) class I-linked microsatellite data and parental assignment data for a group of wild brown trout (Salmo trutta L.) provide evidence of closer spatial aggregation among fry sharing greater numbers of MHC class I alleles under natural conditions. This result confirms predictions from laboratory experiments demonstrating a hierarchical preference for association of fry sharing MHC alleles. Full-siblings emerge from the same nest (redd), and a passive kin association pattern arising from limited dispersal from the nest (redd effect) would predict that all such pairs would have a similar distribution. However, this study demonstrates a strong, significant trend for reduced distance between pairs of full-sibling fry sharing more MHC class I alleles reflecting their closer aggregation (no alleles shared, 311.5 ± (s.e.)21.03 m; one allele shared, 222.2 ± 14.49 m; two alleles shared, 124.9 ± 23.88 m; P<0.0001). A significant trend for closer aggregation among fry sharing more MHC class I alleles was also observed in fry pairs, which were known to have different mothers and were otherwise unrelated (ML-r = 0) (no alleles: 457.6 ± 3.58 m; one allele (422.4 ± 3.86 m); two alleles (381.7 ± 10.72 m); P<0.0001). These pairs are expected to have emerged from different redds and a passive association would then be unlikely. These data suggest that sharing MHC class I alleles has a role in maintaining kin association among full-siblings after emergence. This study demonstrates a pattern consistent with MHC-mediated kin association in the wild for the first time.
主要组织相容性复合体 (MHC) 类 I 连锁微卫星数据和一组野生棕色鳟鱼 (Salmo trutta L.) 的父母分配数据提供了证据，表明在自然条件下，共享更多 MHC 类 I 等位基因的幼鱼之间存在更紧密的空间聚集。这一结果证实了实验室实验的预测，即具有 MHC 等位基因的幼鱼之间存在层次偏好的关联。全同胞来自同一个巢 (redd)，而由于从巢中有限的扩散而产生的被动亲缘关系模式 (redd 效应) 预测所有这些对都将具有相似的分布。然而，这项研究表明，具有更多 MHC 类 I 等位基因的全同胞幼鱼之间的距离明显减小，这反映了它们更紧密的聚集 (无等位基因共享，311.5 ± (s.e.)21.03 m；一个等位基因共享，222.2 ± 14.49 m；两个等位基因共享，124.9 ± 23.88 m；P<0.0001)。在具有不同母亲且彼此无关 (ML-r = 0) 的幼鱼对中，也观察到了共享更多 MHC 类 I 等位基因的幼鱼之间更紧密聚集的显著趋势 (无等位基因：457.6 ± 3.58 m；一个等位基因 (422.4 ± 3.86 m)；两个等位基因 (381.7 ± 10.72 m)；P<0.0001)。这些对预计来自不同的巢，因此不太可能存在被动关联。这些数据表明，在幼鱼出现后，共享 MHC 类 I 等位基因在全同胞之间的亲缘关系中发挥了作用。这项研究首次证明了在野外存在 MHC 介导的亲缘关系的模式。
