The Isolating Potential of a Post-Insemination Barrier to Fertilization

受精后受精障碍的隔离潜力

• 批准号: 9407229
• 负责人: Daniel Howard
• 金额: $ 26.1万
• 依托单位: New Mexico State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-15 至 1998-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9407229&HistoricalAwards=false
• 关键词: Isolating; Potential; Post; Insemination; Barrier

Howard 9407229 Achieving an understanding of the evolution and the nature of reproductive isolation (lack of successful interbreeding between closely related species) is a fundamental goal of biologists. The goal has been elusive, reflecting the difficulty of identifying and characterizing the trait(s) responsible for the onset of reproductive isolation. Only long term studies focusing on closely related species that have been well characterized ecologically and evolutionarily are likely to provide important new insights. A large amount of previous work on the ground crickets Allonemobius fasciatus and A. socius indicates that these sister species are reproductively isolated by a barrier to fertilization that operates after mating. Although described for the first time only recently, this type of reproductive barrier has begun to attract a great deal of attention from biologists as an increasing number of studies indicate that many closely related terrestrial animals are isolated in such a way. In the work proposed here, the barrier to fertilization between A. fasciatus and A. socius will be further characterized by studying patterns of mating in both species, the strength of the barrier to fertilization, and the genetic basis of the barrier. The results of these studies will be used to construct computer simulation models of the reproductive isolating potential of a post-mating barrier to fertilization. A laboratory test to the isolating potential of the fertilization barrier will provide an important check on the computer simulation results. The work described in this proposal explores a new area in speciation research--the role played by post-mating barriers to fertilization in the reproductive isolation of closely related species. At the same time, the work will have bearing on an old debate in biology, whether reproductive isolation arised through mutations of small effect (micromutations) at many genes, or through mutations with large effects (macromutations) at one or a few genes. The proposed work has important implications in two applied fields--agriculture and conservation biology. The family Gryllidae (crickets) includes some very serious agricultural pests. The proposed research will provide badly needed information on reproductive biology of crickets--information that can be used to help develop biological control programs. In conservation biology, the integrity of rare species is often threatened by hybridization with more common sister species. Hence, achieving an understanding of how reproductive barriers operate is critical for preventing the loss of biological diversity.

了解进化和生殖隔离（近亲物种之间缺乏成功的杂交）的本质是生物学家的一个基本目标。这一目标一直难以实现，这反映了确定和描述导致生殖隔离的特征的困难。只有对密切相关的物种进行长期研究，这些物种在生态学和进化上已经有了很好的特征，才有可能提供重要的新见解。先前对地蟋蟀和社会蟋蟀的大量研究表明，这两个姐妹物种在交配后由于受精障碍而在繁殖上被隔离。尽管最近才首次被描述，但这种类型的生殖屏障已经开始引起生物学家的极大关注，因为越来越多的研究表明，许多密切相关的陆生动物都是以这种方式隔离的。在本文中，我们将通过研究两种昆虫的交配模式、受精障碍的强度和屏障的遗传基础来进一步研究筋膜库蚊和社会库蚊之间的受精障碍。这些研究的结果将用于构建交配后受精屏障的生殖隔离潜力的计算机模拟模型。对施肥屏障隔离电位的实验室测试将为计算机模拟结果提供重要的检验。本提案中描述的工作探索了物种形成研究的一个新领域——交配后受精障碍在近亲物种的生殖隔离中所起的作用。与此同时，这项工作将对生物学中一个古老的争论产生影响，即生殖隔离是由于许多基因上的小影响突变（微突变）引起的，还是由于一个或几个基因上的大影响突变（大突变）引起的。这项工作在农业和保护生物学两个应用领域具有重要意义。蟋蟀科（蟋蟀）包括一些非常严重的农业害虫。这项拟议的研究将提供有关蟋蟀生殖生物学的急需信息，这些信息可用于帮助制定生物控制计划。在保护生物学中，稀有物种的完整性经常受到与更常见的姐妹物种杂交的威胁。因此，了解生殖障碍如何起作用对于防止生物多样性的丧失至关重要。