The cost of males in Daphnia pulex
The cost of males in Daphnia pulex
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水蚤雄性的成本
DOI：
10.1111/j.1600-0706.2008.16760.x
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发表时间：
2008
期刊：
影响因子：
3.4
通讯作者：
C. Lively
中科院分区：
文献类型：
--
作者：
J. Wolinska;C. Lively
性是矛盾的，因为无性动物应该通过避免生育男性的人口成本（以下简称男性成本）来取代有性祖先。尽管有大量的理论和实证工作处理性的悖论，但男性成本假设很少得到检验。在本研究中，我们检验了支大洋水蚤的雄性成本假设。该物种的种群包括周期性孤雌生殖（即有性繁殖）和专性孤雌生殖（即无性繁殖）谱系。此外，一些无性谱系只产生雌性后代，而另一些则产生有功能的雄性，它们可以与有性的雌性交配。在不同的环境条件下，我们比较了有性繁殖、雄性无性繁殖和非雄性无性繁殖的生殖投资。我们还确定了这些生殖模式的成对组合之间竞争的结果。当有性和无性的雌性分开饲养时，雄性的代价是显而易见的：有性繁殖的雌性后代更少。然而，当繁殖模式是成对饲养时，雄性没有成本，因为有性繁殖的动物在与无性繁殖的动物的竞争中获胜。我们的结果直接关系到d.p ulex所经历的野外条件。在繁殖季节开始时，资源竞争较低，雌性可能会承受雄性的成本；但是，当条件恶化，人口接近承载能力时，尽管男性生育，但异性似乎是更好的竞争对手。
Sex is paradoxical, because asexuals should replace their sexual ancestors by avoiding the demographic cost of producing males (hereafter referred to as the cost-of-males). Despite the large body of theoretical and empirical work dealing with the paradox of sex, the cost-of-males assumption has been rarely tested. In the present study, we tested the cost-of-males assumption in the cladoceran Daphnia pulex. Populations of this species consist of both cyclically parthenogenetic (i.e. sexuals) and obligately parthenogenetic (i.e. asexuals) lineages. In addition, some of the asexual lineages produce only female offspring, whereas others produce functional males, which can mate with sexual females. We compared the reproductive investment of sexuals, male-producing asexuals, and non-male-producing asexuals when raised separately under various environmental conditions. We also determined the outcome of competition between pair-wise combinations of these reproductive modes. The cost of males was evident when sexual and asexual females were raised separately: sexuals produced fewer female offspring. However, there was no cost of males when reproductive modes were raised in pairs, as sexuals won the competition with asexuals. Our results directly relate to the field conditions experienced by D. pulex. Sexuals might suffer the cost of males at the beginning of the season, when resource competition is low; but when conditions deteriorate as the population approaches carrying capacity, sexuals seem to be better competitors in spite of male production.
影响因子：
3.1
作者：
KONDRASHOV, AS
通讯作者：
KONDRASHOV, AS