Nietlisbach Pirmin, Camenisch Glauco, Bucher Thomas, Slate Jon, Keller Lukas F, Postma Erik
Institute of Evolutionary Biology and Environmental Studies, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.
Department of Animal & Plant Sciences, University of Sheffield, Sheffield, S10 2TN, UK.
Mol Ecol Resour. 2015 Nov;15(6):1486-96. doi: 10.1111/1755-0998.12414. Epub 2015 May 1.
Although linkage maps are important tools in evolutionary biology, their availability for wild populations is limited. The population of song sparrows (Melospiza melodia) on Mandarte Island, Canada, is among the more intensively studied wild animal populations. Its long-term pedigree data, together with extensive genetic sampling, have allowed the study of a range of questions in evolutionary biology and ecology. However, the availability of genetic markers has been limited. We here describe 191 new microsatellite loci, including 160 high-quality polymorphic autosomal, 7 Z-linked and 1 W-linked markers. We used these markers to construct a linkage map for song sparrows with a total sex-averaged map length of 1731 cM and covering 35 linkage groups, and hence, these markers cover most of the 38-40 chromosomes. Female and male map lengths did not differ significantly. We then bioinformatically mapped these loci to the zebra finch (Taeniopygia guttata) genome and found that linkage groups were conserved between song sparrows and zebra finches. Compared to the zebra finch, marker order within small linkage groups was well conserved, whereas the larger linkage groups showed some intrachromosomal rearrangements. Finally, we show that as expected, recombination frequency between linked loci explained the majority of variation in gametic phase disequilibrium. Yet, there was substantial overlap in gametic phase disequilibrium between pairs of linked and unlinked loci. Given that the microsatellites described here lie on 35 of the 38-40 chromosomes, these markers will be useful for studies in this species, as well as for comparative genomics studies with other species.
尽管连锁图谱是进化生物学中的重要工具，但野生种群可用的连锁图谱却很有限。加拿大曼达特岛上的歌带鹀（Melospiza melodia）种群是研究较为深入的野生动物种群之一。其长期的系谱数据以及广泛的基因采样，使得人们能够研究进化生物学和生态学中的一系列问题。然而，遗传标记的可用性一直有限。我们在此描述了191个新的微卫星位点，包括160个高质量的多态性常染色体、7个Z连锁和1个W连锁标记。我们使用这些标记构建了歌带鹀的连锁图谱，总性别平均图谱长度为1731厘摩，覆盖35个连锁群，因此，这些标记覆盖了38 - 40条染色体中的大部分。雌性和雄性的图谱长度没有显著差异。然后，我们通过生物信息学方法将这些位点映射到斑胸草雀（Taeniopygia guttata）基因组上，发现歌带鹀和斑胸草雀之间的连锁群是保守的。与斑胸草雀相比，小连锁群内的标记顺序保守性良好，而较大的连锁群则显示出一些染色体内重排。最后，我们表明，正如预期的那样，连锁位点之间的重组频率解释了配子相位不平衡中的大部分变异。然而，连锁和非连锁位点对之间的配子相位不平衡存在大量重叠。鉴于这里描述的微卫星位于38 - 40条染色体中的35条上，这些标记将有助于该物种的研究，以及与其他物种的比较基因组学研究。
