Identification of a new mating group and reproductive isolation in the Closterium peracerosum-strigosum-littorale complex
Identification of a new mating group and reproductive isolation in the Closterium peracerosum-strigosum-littorale complex
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新月藻-条纹藻-滨海复合体中新交配群的鉴定和生殖隔离
DOI：
10.1007/s10265-018-1043-8
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
H.
中科院分区：
文献类型：
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作者：
Tsuchikane;Y.;Kobayashi;H.;Kato;M.;Watanabe;J.;Wu;J.-T.;Sekimoto;H.
生殖隔离对物种形成过程至关重要。为了了解物种形成，有必要将一个交配群体与其他系统发育相关但生殖隔离的群体进行比较。TheClosterium peracerosum-strigosum-littorale (C。)复合体是一种单细胞的等配体海藻，被认为与陆生植物有着密切的系统发育关系。在这项研究中，我们确定了一个新的交配组，命名为G组，ofC。阻碍。并将其生理生化特征与与交配组g密切相关的交配组I-E进行了比较。合子孢子通常是在有性繁殖过程中由同一交配组中的交配型正（mt+）和交配型负（mt−）细胞结合而形成的。杂交实验表明，G组和I-E组相互生殖分离，但在I-E组mt+细胞存在的情况下，G组的mt -细胞产生了原生质体。事实上，交配组I-E的性信息素、原生质体释放诱导蛋白诱导了交配组G的mt -细胞释放原生质体。当交配组I-E和G的mt+和mt -细胞共培养（多选择交配）时，交配组G的合子形成受到抑制，而交配组I-E的合子形成没有受到抑制。基于这些结果，我们提出了两个交配群体之间生殖隔离的可能机制，并认为交配组G和交配组I-E之间存在性干扰。
Reproductive isolation is essential for the process of speciation. In order to understand speciation, it is necessary to compare one mating group with other phylogenetically related but reproductively isolated groups. TheClosterium peracerosum–strigosum–littorale(C. psl.) complex is a unicellular isogamous zygnematophycean alga, which is believed to share a close phylogenetic relationship with the land plants. In this study, we identified a new mating group, named group G, ofC. psl. complex and compared its physiological and biochemical characteristics with the mating group I-E, which was closely related to the mating group G. Zygospores are typically formed as a result of conjugation between mating-type plus (mt+) and mating-type minus (mt−) cells in the same mating group during sexual reproduction. Crossing experiments revealed mating groups G and I-E were reproductively isolated from each other, but the release of lone protoplasts from mt−cells of mating group G was induced in the presence of mt+cells of mating group I-E. In fact, the sex pheromone, protoplast-release-inducing protein of mating group I-E induced the release of protoplasts from mt−cells of mating group G. When mt+and mt−cells of both mating groups I-E and G were co-cultured (multiple-choice matings), the zygospore formation of mating group G, but not that of mating group I-E, was inhibited. Based on these results, we propose a possible mechanism of reproductive isolation between the two mating groups and suggest the presence of sexual interference between mating group G and mating group I-E.