Meiotic hybridogenesis in triploid Misgurnus loach derived from a clonal lineage
Meiotic hybridogenesis in triploid Misgurnus loach derived from a clonal lineage
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DOI：
10.1038/hdy.2008.17
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发表时间：
2008-06
期刊：
影响因子：
3.8
通讯作者：
K. Morishima;K. Morishima;Hiroyuki Yoshikawa;K. Arai
中科院分区：
文献类型：
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作者：
K. Morishima;K. Morishima;Hiroyuki Yoshikawa;K. Arai
三倍体泥鳅（Misgurnus anguillicaudatus）是由一个无性克隆谱系产生的未还原的二倍体配子衍生而来，该谱系通常经历雌性生殖。在这里，我们研究了两种类型的三倍体的生殖系统：第一类携带来自同一群体的母系遗传的克隆二倍体基因组和父系遗传的单倍体基因组；第二种类型具有相同的克隆二倍体基因组，但单倍体基因组来自另一个遗传上不同的群体。三倍体雌性（3n= 75）卵母细胞的生发囊泡仅含有25个二价体，即50条染色体。流式细胞术显示，三倍体雌性与正常单倍体精子受精后产生的后代大部分为二倍体。这表明三倍体雌性主要产生单倍体卵。对三倍体雌性二倍体后代的微卫星分析表明，该克隆基因型的一个等位基因没有传递给单倍体卵。此外，消除等位基因的身份在两种三倍体之间存在差异。我们的研究结果表明，在单倍体卵子形成过程中，同源染色体优先配对，不匹配染色体的消除，即减数分裂杂交发生。克隆中两个不同的基因组表明它的杂交起源。
Triploid loaches Misgurnus anguillicaudatus are derived from unreduced diploid gametes produced by an asexual clonal lineage that normally undergoes gynogenetic reproduction. Here, we have investigated the reproductive system of two types of triploids: the first type carried maternally inherited clonal diploid genomes and a paternally inherited haploid genome from the same population; the second type had the same clonal diploid genomes but a haploid genome from another, genetically divergent population. The germinal vesicles of oocytes from triploid females (3n= 75) contained only 25 bivalents, that is, 50 chromosomes. Flow cytometry revealed that the majority of the progeny resulting from fertilization of eggs from triploid females with normal haploid sperm were diploid. This indicates that triploid females mainly produced haploid eggs. Microsatellite analyses of the diploid progeny of triploid females showed that one allele of the clonal genotype was not transmitted to haploid eggs. Moreover, the identity of the eliminated allele differed between the two types of triploids. Our results demonstrate that there is preferential pairing of homologous chromosomes as well as the elimination of unmatched chromosomes in the course of haploid egg formation, that is, meiotic hybridogenesis. Two distinct genomes in the clone suggest its hybrid origin.