Ecology and genetics of hybrid animals

杂交越来越被认为是动物进化中的一种多样化力量。高杂交适应性在新的、边缘的或动态的栖息地中更常见。然而，更高的混合健身的原因，只有部分已知。我的研究项目采用了一种综合方法，涉及实地和实验研究，再加上遗传特征，以研究新的遗传组合如何在动态生态环境中提供更高的适应性。我利用底杂交复合体，其中两种鱼类（底heteroclitus和F。在不同的盐度下，典型的白腹透翅目（diaphanus）已经杂交产生有性生殖和雌核发育的杂种。后者包括全雌性克隆，需要来自底属雄性的精子来触发卵子发育。进行生态调查，以建立在栖息地的中间和/或可变的盐度，如河口，潮汐急流，沿海湖泊和泻湖的父母和混合形式的相对分布。与此同时，初步估计的混合频率，渐渗水平和克隆多样性细化全基因组的遗传特征与AFLP标记。生态学和遗传学知识通过检查与健康相关的特征，如离子调节能力，野外（移植实验）和实验室（普通花园实验）中的生存和生长来结合。在这里，固定的克隆基因型的可用性是特别合适的解开遗传，母体，环境来源的表型变异影响健身组件。鉴于其恒定的遗传背景，克隆也可用于检查杂交体中等位基因的表达。这种对天然雌核发育的综合分析将为检验关于克隆生态宽度的竞争假说提供机会。这项研究也将与功能和环境生理学和基因组学领域有关，这些领域使用F。heteroclitus作为模式生物。这项拟议中的研究将涉及一名博士，三M。Sc.，和五个B。理科学生。这些学生将接受从整体角度记录和解释生态，表型和遗传变异的培训。

Hybridization is increasingly recognized as a diversifying force in animal evolution. High hybrid fitness is more frequent in novel, marginal, or dynamic habitats. Causes of higher hybrid fitness, however, are only partly known. My research program employs an integrative approach involving field and experimental studies coupled with genetic characterization to investigate how new genetic combinations can provide higher fitness in dynamic ecological settings. I take advantage of the Fundulus hybrid complex where two fish species (Fundulus heteroclitus and F. diaphanus) typically found at different salinities have hybridized to produce sexually reproducing and gynogenetic hybrids. The latter comprises all-female clones that need sperm from Fundulus males to trigger egg development. Ecological surveys are conducted to establish the relative distribution of parental and hybrid forms in habitats of intermediate and/or variable salinity such as estuaries, tidal rapids, coastal lakes and lagoons. In parallel, preliminary estimates of hybrid frequency, introgression levels and clonal diversity are refined by genome-wide genetic characterization with AFLP markers. Ecological and genetic knowledge are coupled by examining fitness-related traits such as ionoregulation ability, survival and growth in the field (transplant experiments) and in the lab (common garden experiments). Here, the availability of fixed clonal genotypes is particularly appropriate to disentangle the genetic, maternal, environmental sources of phenotypic variation impacting on fitness components. Given their constant genetic background, clones are also useful to examine allelic gene expression in hybrids. This integrated analysis of natural gynogens will offer opportunities to test competing hypothesis on the ecological breadth of clones. This research will also be relevant to the fields of functional and environmental physiology and genomics, which use F. heteroclitus as a model organism. The proposed research will involve one Ph. D., three M. Sc., and five B. Sc students. These students will be trained in documenting and interpreting ecological, phenotypic and genetic variation from a holistic point of view.