Dvorák J, Luo M C, Yang Z L
Department of Agronomy and Range Science, University of California, Davis 95616, USA.
Genetics. 1998 Jan;148(1):423-34. doi: 10.1093/genetics/148.1.423.
RFLP was investigated at 52 single-copy gene loci among six species of Aegilops, including both cross-fertilizing and self-fertilizing species. Average gene diversity (H) was found to correlate with the level of outcrossing. No relationship was found between H and the phylogenetic status of a species. In all six species, the level of RFLP at a locus was a function of the position of the locus on the chromosome and the recombination rate in the neighborhood of the locus. Loci in the proximal chromosome regions, which show greatly reduced recombination rates relative to the distal regions, were significantly less variable than loci in the distal chromosome regions in all six species. Variation in recombination rates was also reflected in the haplotype divergence between closely related species; loci in the chromosome regions with low recombination rates were found to be diverged less than those in the chromosome regions with high recombination rates. This relationship was not found among the more distantly related species.
在包括异花授粉和自花授粉物种在内的六种山羊草属物种中的52个单拷贝基因座处研究了限制性片段长度多态性（RFLP）。发现平均基因多样性（H）与异交水平相关。未发现H与物种的系统发育地位之间存在关系。在所有六个物种中，一个基因座处的RFLP水平是该基因座在染色体上的位置以及该基因座附近重组率的函数。相对于远端区域，近端染色体区域中的基因座显示出大大降低的重组率，在所有六个物种中，这些基因座的变异性明显低于远端染色体区域中的基因座。重组率的变化也反映在近缘物种之间的单倍型差异中；发现重组率低的染色体区域中的基因座比重组率高的染色体区域中的基因座分歧更小。在亲缘关系较远的物种中未发现这种关系。
