A Genetic Map for the Only Self-Fertilizing Vertebrate.
A Genetic Map for the Only Self-Fertilizing Vertebrate.
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DOI：
10.1534/g3.115.022699
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发表时间：
2016-04-07
期刊：
影响因子：
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通讯作者：
Sakakura Y
中科院分区：
文献类型：
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作者：
Kanamori A;Sugita Y;Yuasa Y;Suzuki T;Kawamura K;Uno Y;Kamimura K;Matsuda Y;Wilson CA;Amores A;Postlethwait JH;Suga K;Sakakura Y
红树林鳉鱼Kryptolebias marmoratus和它的近亲Kryptolebias hermaphroditus是已知的唯一通过自花受精繁殖的脊椎动物物种，这是由于功能性的卵睾丸发育。为了加深我们对它们基因组的了解，我们构建了一个基因图谱。首先，采用人工受精的方法，在K. marmoratus和K.雌雄同体株。然后通过F1鱼的自花受精获得F2后代。我们使用RAD-seq查询来自两个亲本菌株，F1个体和49个F2后代的基因组DNA。结果确定了9904多态性的RAD标签（DNA标记），映射到24个连锁群，对应于这些物种的单倍体染色体数目。该图谱的总长度为1248 cM，表明在每次减数分裂中，24对同源染色体中的每对都发生了约一次重组。标记并不是沿着染色体均匀分布的：在所有染色体中，许多标记（>每条染色体总标记的8%）映射到染色体尖端。着丝粒抑制重组，这种不均匀的分布可能是由于物种的近端着丝粒染色体。将绘制的标记序列与青鳉和小鳞鱼的基因组序列进行比较，青鳉和小鳞鱼是与基因图谱锚定的测序基因组最接近的物种。结果表明，每个红树林鳉染色体对应于一个单一的染色体，这表明染色体在1亿年的进化中具有很强的保守性。我们的遗传图谱为K. marmoratus/花斑隐翅虫K.雌雄同体的基因组序列和了解两性畸形生物学的重要资源。
The mangrove killifish Kryptolebias marmoratus, and its close relative Kryptolebias hermaphroditus, are the only vertebrate species known to reproduce by self-fertilization due to functional ovotestis development. To improve our understanding of their genomes, we constructed a genetic map. First, a single F1 fish was made by artificial fertilization between K. marmoratus and K. hermaphroditus strains. F2 progeny were then obtained by self-fertilization of the F1 fish. We used RAD-seq to query genomic DNAs from the two parental strains, the F1 individual and 49 F2 progeny. Results identified 9904 polymorphic RAD-tags (DNA markers) that mapped to 24 linkage groups, corresponding to the haploid chromosome number of these species. The total length of the map was 1248 cM, indicating that about one recombination occurred for each of the 24 homologous chromosome pairs in each meiosis. Markers were not evenly distributed along the chromosomes: in all chromosomes, many markers (> 8% of the total markers for each chromosome) mapped to chromosome tips. Centromeres suppress recombination, and this uneven distribution is probably due to the species’ acrocentric chromosomes. Mapped marker sequences were compared to genomic sequences of medaka and platyfish, the next most closely related species with sequenced genomes that are anchored to genetic maps. Results showed that each mangrove killifish chromosome corresponds to a single chromosome of both platyfish and medaka, suggesting strong conservation of chromosomes over 100 million years of evolution. Our genetic map provides a framework for the K. marmoratus/K. hermaphroditus genome sequence and an important resource for understanding the biology of hermaphroditism.