The molecular basis of morphological change; antennal variation in crustaceans

描述(由申请人提供)：确定形态差异是如何产生的是进化生物学中一个非常重要的课题，但一直很难通过实验解决。然而，随着最近进化和发育生物学(EVO-DEVO)领域的出现，现在将新的和有趣的物种带入实验室询问分子和遗传学问题变得可行。大多数EVO-DEVO研究要么关注宏观进化(大规模)，要么关注微观进化(小规模)。微进化研究在发现引起形态变化的遗传变化方面非常有价值，因为所讨论的种群之间的时间差相对较短。一个仍然存在的问题是，微进化的路径是否在较短的时间尺度上代表了较大时间尺度上的变化路径。为了真正理解物种形成中形态变化的进化，我们需要解决一个看似不可能的目标，即观察被巨大时差隔开的物种的形态进化的遗传学。弥合短时间尺度的进化和长时间尺度的进化之间的差距的一种方法是观察一种在物种内和物种之间都显示出巨大多样性的形态。我们建议在三个不同的时间尺度上从分子和遗传学上研究触角的发育：昆虫和甲壳类动物之间，不同甲壳类物种之间，以及具有种内触角变异的甲壳类物种内。我们将使用候选基因方法，分析具有不同触角形态的甲壳类物种中与触角发育有关的已知基因的基因表达。我们还将在夏威夷甲壳类动物中寻找其中一些基因，这是一种可以进行分子分析的物种。使用候选遗传方法，我们将检查具有洞穴和地表栖息地种群的物种的种内触角变异。从医学的角度来看，研究表型变化背后的遗传和分子基础是非常重要的；人类遗传学的主要目标之一是找出哪些基因变化是导致疾病和其他疾病的原因。了解物种表型变化的遗传和分子基础(在实验室进行实验是可能的)将使人们能够深入了解进化过程：哪些类型的基因受到影响，这些基因中有哪些类型的突变，以及特定特征中有多少变异是由遗传和环境编码的。这些信息将产生对进化变化的更多了解，这将有助于对人类基因组的分析。

DESCRIPTION (provided by applicant): Determining how morphological differences arise is a subject of great importance in evolutionary biology but one that has been very difficult to address experimentally. However, with the recent advent of the field of evolutionary and developmental biology (evo-devo), it is now becoming feasible to bring new and interesting species into the lab to ask molecular and genetic questions. Most evo-devo studies either focus on macroevolution (large-scale) or microevolution (small-scale). Microevolutionary studies have been very valuable in discovering genetic changes causing morphological change because the time difference separating the populations in question is relatively short. One question that still remains is whether the path of microevolutionary change represents on a shorter time scale the path of changes on a larger time scale. To really understand the evolution of morphological change in speciation, we need to address the seemingly impossible goal of looking at the genetics of morphological evolution in species separated by great time differences. One way of bridging the gap between evolution on a short time scale and evolution on a longer time scale is to look at a morphology that shows great diversity both within species and between species. We propose to study antennal development molecularly and genetically across three different time scales: between insects and crustaceans, between different crustacean species, and within a crustacean species that has intraspecific antennal variation. We will be using a candidate gene approach, assaying gene expression of genes known to be involved in antennal development in insects in crustacean species with differing antennal morphologies. We will also functionally pursue some of these genes in the crustacean Parhyale hawaiensis, a species amenable to molecular analyses. Using a candidate genetic approach, we will examine intraspecific antennal variation in a species that has cave and surface dwelling populations. Studying the genetic and molecular basis behind phenotypic change is very important from a medical standpoint; one of the major goals in human genetics is to figure out what genetic changes are responsible for diseases and other conditions. Understanding the genetic and molecular basis of phenotypic change in species in which laboratory experiments are possible will allow insight into the process of evolution: what types of genes are affected, what types of mutations are in these genes, and how much of the variation in a particular trait is encoded genetically and environmentally. This information will yield a greater understanding of evolutionary change which will be helpful in the analysis of the human genome.