Geographical parthenogenesis in the brown alga Scytosiphon lomentaria (Scytosiphonaceae): Sexuals in warm waters and parthenogens in cold waters
Geographical parthenogenesis in the brown alga Scytosiphon lomentaria (Scytosiphonaceae): Sexuals in warm waters and parthenogens in cold waters
复制标题
DOI：
10.1111/mec.16152
复制
发表时间：
2021-03
影响因子：
4.9
通讯作者：
Masakazu Hoshino;Shimpei F Hiruta;M. Croce;M. Kamiya;Takahiro Jomori;T. Wakimoto;K. Kogame
中科院分区：
文献类型：
--
作者：
Masakazu Hoshino;Shimpei F Hiruta;M. Croce;M. Kamiya;Takahiro Jomori;T. Wakimoto;K. Kogame
地理孤雌生殖是指孤雌生殖动物及其近缘有性生殖动物在不同地理区域内的生殖现象，是进化生物学研究的热点。关于陆地和淡水的地理单性生殖的报道很多，但这种情况很少在海洋中报道。褐藻大多是海洋藻类，被认为包括许多专性孤雌生殖体;然而，很少有人知道孤雌生殖体在这个组中的分布，起源和进化。在这里，我们报告了一种新的模式的地理孤雌生殖的同花受精棕色的Scytosiphon lomentaria。性比调查表明，在日本，有性种群增长在沿海沿着温暖的洋流，而女性占主导地位的孤雌生殖种群主要增长在沿海沿着冷洋流。在两个地方的性和孤雌生殖人口是parapatric，孤雌生殖增长在更多的波暴露领域比性。群体遗传和系统发育分析，包括基于全基因组单核苷酸多态性数据的分析，表明孤雌生殖者最初至少进化了两次，随后孤雌生殖者和有性生殖者之间的杂交产生了多个新的孤雌生殖谱系。最初的孤雌生殖体的起源尚不清楚，但它不会是种间杂交。有趣的是，我们发现吸引雄配子的性信息素的产生在最初的两个孤雌生殖谱系中已经独立地消失了。这种性特征的平行丧失可能代表了单性生殖的直接起源，或者是无性生殖下无用特征的退化进化。
Geographical parthenogenesis, a phenomenon where parthenogens and their close sexual relatives inhabit distinct geographical areas, has been considered an interesting topic in evolutionary biology. Reports of geographical parthenogenesis from land and freshwater are numerous, but this occurrence has been rarely reported from the sea. Brown algae are mostly marine and are thought to include numerous obligate parthenogens; still, little is known about the distribution, origin and evolution of parthenogens in this group. Here we report a novel pattern of geographical parthenogenesis in the isogamous brown alga Scytosiphon lomentaria. Sex ratio investigation demonstrated that, in Japan, sexual populations grew in the coast along warm ocean currents, whereas female‐dominant parthenogenetic populations grew mainly in the coast along a cold ocean current. In the two localities where sexual and parthenogenetic populations were parapatric, parthenogens grew in more wave‐exposed areas than sexuals. Population genetic and phylogenetic analyses, including those based on genome‐wide single nucleotide polymorphism data, indicated that parthenogens have initially evolved at least twice and subsequent hybridizations between the parthenogens and sexuals have generated multiple new parthenogenetic lineages. The origin of the initial parthenogens is not clear, except that it would not be interspecies hybridization. Interestingly, we found that the production of sex pheromones, which attract male gametes, has been independently lost in the initial two parthenogenetic lineages. This parallel loss of the sexual trait may represent the direct origin of parthenogens, or the regressive evolution of a useless trait under asexuality.