Dissertation Research: Fine Scale Evolutionary Adaptation to Temperature: A Comparative Approach Using Porcelain Crabs(genus Petrolisthes)

索梅罗9700701 石蟹属的海洋瓷蟹分布在很广的地理范围--从极热的热带环境到寒冷的北温带和南温带地区--以及潮间带和潮下带的不同高度。因此，同类岩蟹遇到了很大的差异，平均温度和温度范围内，使这些螃蟹一个很好的研究系统，研究进化适应温度在一个相对狭窄的分类组。PI的两个同源物，P. eriomerus和P. cinctipes的初步研究，分别从低和高潮间带，表明普遍适应温度和浮现压力。拟议的研究以这项工作为基础，并针对其他几种同系物开展以下研究：（1）确定致死温度上限;（2）检查乳酸脱氢酶的结构和动力学特性对温度的敏感性;（3）确定腿部膜结构在气体交换中的功能;以及（4）利用大亚基核糖体RNA基因的序列开发分子系统发生。后面的实验将使得能够在系统发生背景下分析生理-生化-分子性状的种间差异，从而使假定的“适应性”差异能够与不是由于对温度的进化反应而引起的变化区分开来。 .

Somero 9700701 Marine porcelain crabs of the genus Petrolisthes occur over a wide geographical range--from extremely hot tropical environments to cold north- and south temperate regions--and at widely different heights in the intertidal and subtidal zones. Thus, congeners of Petrolisthes encounter substantial differences in mean temperature and temperature range, making these crabs an excellent study system for examining evolutionary adaptation to temperature within a relatively narrow taxonomic group. The PI's initial studies of two congeners, P. eriomerus and P. cinctipes from low- and high intertidal zones, respectively, indicate pervasive adaptations to temperature and emersion stress. The proposed studies build on this work, and include, for several additional congeners: (1) determination of upper lethal temperature limits; (2) examination of the temperature sensitivity of structural and kinetic properties of lactate dehydrogenase; (3) determination of the function of leg membrane structures in gas exchange; and (4) development of a molecular phylogeny, using the sequence of the large subunit ribosomal RNA gene The latter experiments will enable analysis of the interspecific differences in physiological-biochemical-molecular traits to be analyzed in a phylogenetic context, thus enabling putative "adaptive" differences to be distinguished from changes not due to evolutionary responses to temperatures. .