The Maintenance of Unisexuality: Behavior, Hormones, and Genetic Diversity in a Unisexual-Bisexual Mating Complex

单性恋的维持：单性恋-双性恋交配复合体中的行为、激素和遗传多样性

• 批准号: 1021873
• 负责人: Caitlin Gabor
• 金额: $ 35万
• 依托单位: Texas State University - San Marcos
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1021873&HistoricalAwards=false
• 关键词: Maintenance; Unisexuality; Behavior; Hormones; Genetic

Unisexual species consist of only females (there are no males), and their persistence is an evolutionary paradox because they do not benefit from the increase in genetic variation that results from sexual reproduction. Gynogenesis is a type of unisexual reproduction that occurs when an all-female species must mate with males of closely related species (hosts) to stimulate the development of their eggs, but a male's sperm does not fertilize the eggs. Gynogenetic species face two major challenges. Because they produce only female offspring, they reproduce at a higher rate than sexual species, which can cause extinction of the sexual host via competitive exclusion (followed afterward by extinction of the gynogens). Furthermore, males of the host species should evolve to avoid mating with unisexuals because they do not pass on their genes when mating with gynogens. Solving this paradox can shed light on costs and benefits of sexual and unisexual reproduction. This research addresses hypotheses about maintenance of unisexuals in a mating system consisting of the gynogenetic fish, the Amazon molly, and its hosts, the sailfin molly and the Atlantic molly. This project investigates how hormone levels of the male hosts and the relative abundance of Amazon mollies affect the propensity of males to mis-mate with Amazon mollies, and will determine whether extinction and colonization of inter-connected populations can explain the maintenance of Amazons mollies, even though they should outcompete their host in a local population. The project will provide information about how complex interactions between species influence the evolution of reproductive strategies. The interesting nature of this system makes it appealing for K-12 and college students. This work will include participation by students and the investigators will give talks and conduct outreach activities related to these studies. Finally, this project will involve underrepresented groups in biology.

单性物种只由雌性组成（没有雄性），它们的持续存在是一个进化悖论，因为它们没有从有性繁殖带来的遗传变异的增加中受益。雌性生殖是一种单性生殖，当一个全雌性物种必须与近亲物种（宿主）的雄性交配以刺激其卵子的发育时，雄性的精子不会使卵子受精。雌核发生物种面临两个主要挑战。因为它们只产生雌性后代，它们的繁殖率比有性物种高，这可能会通过竞争排斥导致有性宿主的灭绝（随后是雌核原的灭绝）。此外，寄主物种的雄性应该进化到避免与单性动物交配，因为它们在与雌性交配时不会传递自己的基因。解决这一悖论可以揭示有性生殖和单性生殖的成本和收益。这项研究提出了在一个由亚马孙莫利及其宿主帆船莫利和大西洋莫利组成的交配系统中维持雌雄同体的假设。该项目调查了雄性宿主的激素水平和亚马逊molis的相对丰度如何影响雄性与亚马逊molis错配的倾向，并将确定相互关联的种群的灭绝和殖民化是否可以解释亚马逊molis的维持，即使它们在当地种群中应该比宿主更有竞争力。该项目将提供有关物种之间复杂的相互作用如何影响生殖策略进化的信息。这个系统的有趣性质使它对K-12和大学生很有吸引力。这项工作将包括学生的参与，研究者将进行与这些研究相关的演讲和外展活动。最后，这个项目将涉及生物学中代表性不足的群体。