Microsatellite-centromere mapping in common carp through half-tetrad analysis in diploid meiogynogenetic families
Microsatellite-centromere mapping in common carp through half-tetrad analysis in diploid meiogynogenetic families
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DOI：
10.1007/s00412-014-0485-6
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发表时间：
2015-03-01
期刊：
影响因子：
1.6
通讯作者：
Tong, Jingou
中科院分区：
文献类型：
--
作者：
Feng, Xiu;Wang, Xinhua;Tong, Jingou
基因-着丝粒（G-C）图谱为了解脊椎动物基因组的组成、结构和进化提供了见解。鲤鱼（Cyprinus carpio）是一种重要的水产养殖鱼类，已被提议进行四倍化。在本研究中，我们选择了214个微卫星标记的50个连锁群的一个共同的鲤鱼遗传图谱进行基因-着丝粒定位使用半四分体分析。在3个雌核发育家系中至少有一个家系中，共分离出199个微卫星，并用于G-C距离估计。G-C重组频率（y）在0 ~ 0.99之间，平均为0.43，雌核发育一代后的固定指数（F）为0.57。某些位点的y值较大，G-C距离与遗传连锁图距离呈显著相关，表明鲤鱼存在较高的遗传干扰。在完全干扰的假设下，将50个着丝粒定位到鲤鱼相应的连锁群上，每个连锁群的着丝粒连锁标记的G-C距离为0 ~ 10.3cM，平均为2.9cM。根据着丝粒位置信息，提出鲤鱼染色体公式为2n = 100 = 58 m/sm + 42 t/st，具有158条染色体臂，这与细胞遗传学方法观察到的结果相似。沿着沿着10个LG的交叉分布的检查显示，在雌核发育后代中，交叉染色单体的比例总体上高于非交叉染色单体的比例，表明在大多数LG中的高重组水平。比较基因组学分析表明，鲤鱼的染色体在基因组复制后发生了广泛的重排。本研究对阐明鲤鱼基因组进化机制、整合物理图谱和遗传图谱具有重要意义。
Gene-centromere (G-C) mapping provides insights into the understanding of the composition, structure, and evolution of vertebrate genomes. Common carp (Cyprinus carpio) is an important aquaculture fish and has been proposed to undertake tetraploidization. In this study, we selected 214 informative microsatellite markers across 50 linkage groups of a common carp genetic map to perform gene-centromere mapping using half-tetrad analysis. A total of 199 microsatellites were segregated under the Mendelian expectations in at least one of the three gynogenetic families and were used for G-C distance estimation. The G-C recombination frequency (y) ranged from 0 to 0.99 (0.43 on average), corresponding to a fixation index (F) of 0.57 after one generation of gynogenesis. Large y values for some loci together with significant correlation between G-C distances and genetic linkage map distances suggested the presence of high interference in common carp. Under the assumption of complete interference, 50 centromeres were localized onto corresponding linkage groups (LGs) of common carp, with G-C distances of centromere-linked markers per LG ranging from 0 to 10.3 cM (2.9 cM on average). Based on the information for centromere positions, we proposed a chromosome formula of 2n = 100 = 58 m/sm + 42 t/st with 158 chromosome arms for common carp, which was similar to a study observed by cytogenetic method. The examination of crossover distributions along 10 LGs revealed that the proportion of crossover chromatids was overall higher than that of non-crossover chromatids in gynogenetic progenies, indicating high recombination levels across most LGs. Comparative genomics analyses suggested that the chromosomes of common carp have undergone extensive rearrangement after genome duplication. This study would be valuable to elucidate the mechanism of genome evolution and integrate physical and genetic maps in common carp.