Optional Endoreplication and Selective Elimination of Parental Genomes during Oogenesis in Diploid and Triploid Hybrid European Water Frogs
Optional Endoreplication and Selective Elimination of Parental Genomes during Oogenesis in Diploid and Triploid Hybrid European Water Frogs
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DOI：
10.1371/journal.pone.0123304
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发表时间：
2015-04-20
期刊：
影响因子：
3.7
通讯作者：
Krasikova, Alla
中科院分区：
文献类型：
--
作者：
Dedukh, Dmitry;Litvinchuk, Spartak;Krasikova, Alla
亲本基因组之间的不相容性降低种间杂种的生存能力;然而，偏离典型的配子发生，如基因组内复制和消除，可以拯救杂种生物。为了评估不同倍性的杂交动物配子发生过程中基因组消除和内复制的频率和规律，我们研究了二倍体和三倍体杂交蛙的卵母细胞的基因组组成。所获得的结果使我们能够表明，在卵子发生过程中的内复制涉及所有的基因组发生之前的选择性基因组消除。我们接受了这样的假设，即在大多数三倍体杂种雌性中，只有一个拷贝的基因组在减数分裂前被消除。与此同时，我们否定了双亲种杂交蛙的基因组在二倍体杂交蛙的卵子发生过程中总是被消除的假设。二倍体杂交蛙在卵子发生上的变异频率比三倍体杂交蛙大。典型的杂交青蛙配子发生的偏差增加了配子的变异性，并提供了一种机制，出现不同形式的杂交种。
Incompatibilities between parental genomes decrease viability of interspecific hybrids; however, deviations from canonical gametogenesis such as genome endoreplication and elimination can rescue hybrid organisms. To evaluate frequency and regularity of genome elimination and endoreplication during gametogenesis in hybrid animals with different ploidy, we examined genome composition in oocytes of di- and triploid hybrid frogs of the Pelophylax esculentus complex. Obtained results allowed us to suggest that during oogenesis the endoreplication involves all genomes occurring before the selective genome elimination. We accepted the hypothesis that only elimination of one copied genome occurs premeiotically in most of triploid hybrid females. At the same time, we rejected the hypothesis stating that the genome of parental species hybrid frogs co-exist with is always eliminated during oogenesis in diploid hybrids. Diploid hybrid frogs demonstrate an enlarged frequency of deviations in oogenesis comparatively to triploid hybrids. Typical for hybrid frogs deviations in gametogenesis increase variability of produced gametes and provide a mechanism for appearance of different forms of hybrids.