FISH Identifies Chromosome Differentiation Between Contemporary Genomes of Wild Types and the Ancestral Genome of Unisexual Clones of Dojo Loach, Misgurnus anguillicaudatus
FISH Identifies Chromosome Differentiation Between Contemporary Genomes of Wild Types and the Ancestral Genome of Unisexual Clones of Dojo Loach, Misgurnus anguillicaudatus
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DOI：
10.1159/000515107
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发表时间：
2021-05
影响因子：
1.7
通讯作者：
Masamichi Kuroda;K. Shibata;T. Fujimoto;M. Murakami;E. Yamaha;K. Arai
中科院分区：
文献类型：
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作者：
Masamichi Kuroda;K. Shibata;T. Fujimoto;M. Murakami;E. Yamaha;K. Arai
在道场泥鳅（泥鳅anguillicaudatus），虽然大多数野生型是雌雄异株二倍体的遗传分化成2组，A和B，克隆谱系出现在某些地方。通过一系列遗传学研究，克隆泥鳅被认为是这两个类群之间的杂种起源。本研究利用一种新开发的探针（ManDra-A）进行荧光原位杂交（FISH），从当代野生型A组泥鳅的50条二倍体染色体中鉴定出26条（1对中部着丝粒染色体和12对端部着丝粒染色体）。与此相反，ManDra-A信号没有检测到的中间着丝粒染色体来自祖先组A的克隆泥鳅。FISH结果清楚地表明，祖先和当代A组泥鳅的中部着丝粒染色体存在一定的分化。ManDra-A和B组特异性ManDra（重命名为ManDra-B）探针的双色FISH通过鉴定中期A组和B组的染色体再次证实了克隆的杂交起源。我们的研究结果表明，杂交起源的克隆繁殖鱼类和祖先和当代鱼类之间的染色体分化的可能性，可以影响配子发生。在减数分裂精母细胞的性逆转克隆，ManDra-A，而不是ManDra-B，信号中检测到12的50个二价体。因此，这些结果进一步支持了先前的结论，即克隆配子发生是通过从A组或B组的每个祖先染色体复制的姐妹染色体之间的配对来保证的。本研究加深了对单性脊椎动物克隆性与杂种性关系的认识。
In dojo loach (Misgurnus anguillicaudatus), although most wild types are gonochoristic diploids that are genetically differentiated into 2 groups, A and B, clonal lineages appear in certain localities. Clonal loaches have been considered to have hybrid origins between the 2 groups by a series of genetic studies. In this study, using FISH with a newly developed probe (ManDra-A), we identified 26 (1 pair of metacentric and 12 pairs of telocentric chromosomes) of 50 diploid chromosomes in contemporary wild-type group A loach. In contrast, ManDra-A signals were not detected on metacentric chromosomes derived from the ancestral group A of clonal loach. The FISH results clearly showed the presence of certain differentiations in metacentric chromosomes between ancestral and contemporary group A loach. Two-color FISH with ManDra-A and group B-specific ManDra (renamed ManDra-B) probes reconfirmed the hybrid origin of clones by identifying chromosomes from both groups A and B in metaphases. Our results showed the hybrid origin of clonally reproducing fish and the possibility that chromosomal differentiation between ancestral and contemporary fish can affect gametogenesis. In meiotic spermatocytes of sex-reversed clones, ManDra-A, and not ManDra-B, signals were detected in 12 out of 50 bivalents. Thus, the results further support the previous conclusion that clonal gametogenesis was assured by pairing between sister chromosomes duplicated from each ancestral chromosome from group A or B. Our study deepens the knowledge about the association between clonality and hybridity in unisexual vertebrates.