Hale M C, Jensen H, Birkhead T R, Burke T, Slate J
Department of Animal and Plant Sciences, University of Sheffield, Western Bank, Sheffield, UK.
Cytogenet Genome Res. 2008;121(2):120-9. doi: 10.1159/000125837. Epub 2008 Jun 9.
Wild populations of passerine birds have frequently been used in studies of ecology and evolution. However, the majority of species lack genetic linkage maps. The completion of a model avian genome sequence (the jungle fowl, Gallus gallus) has created an opportunity to advance genetic knowledge of other birds. Here we constructed genetic linkage maps of the homologue of chicken chromosome 7 for two passerine species, the zebra finch (Taeniopygia guttata) and the house sparrow (Passer domesticus). Linkage groups were constructed with a combination of SNP and microsatellite markers that were developed both in silico based on similarity to the chicken genome sequence, and de novo in the laboratory. Synteny was well conserved throughout the chromosome; however there were some gene rearrangements between chickens and passerines. This suggests that the transfer of map information from chicken to passerine and between different passerine species should not assume conserved gene order. The length of linkage maps of chromosome 7 were on average 60% that of chicken, consistent with the idea that passerines have a reduced recombination rate relative to chicken. Some evidence of heterochiasmy, i.e. a difference in the recombination rate between the sexes, was observed.
雀形目鸟类的野生种群经常被用于生态学和进化研究。然而，大多数物种缺乏遗传连锁图谱。模式鸟类基因组序列（原鸡，家鸡）的完成创造了一个推进其他鸟类遗传知识的机会。在这里，我们构建了两种雀形目物种——斑胸草雀（Taeniopygia guttata）和家麻雀（Passer domesticus）——的鸡7号染色体同源物的遗传连锁图谱。连锁群是通过单核苷酸多态性（SNP）和微卫星标记的组合构建而成的，这些标记既有基于与鸡基因组序列相似性在计算机上开发的，也有在实验室中从头开发的。整个染色体上的同线性保存良好；然而，鸡和雀形目之间存在一些基因重排。这表明，从鸡到雀形目以及不同雀形目物种之间的图谱信息转移不应假定基因顺序是保守的。7号染色体的连锁图谱长度平均为鸡的60%，这与雀形目相对于鸡的重组率降低的观点一致。观察到了一些异配现象的证据，即两性之间重组率的差异。
