Format

Send to

Choose Destination

Environmental adaptations as windows on molecular evolution.

Author information

1
Department of Biology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada, N2L 3G1. pschulte@sciborg.uwaterloo.ca

Abstract

Changes in gene regulation may play an important role in adaptive evolution, particularly during adaptation to a changing environment. However, little is known about the molecular mechanisms underlying adaptively significant variation in gene regulation. To address this question, we are using environmental adaptations in populations of a fish, Fundulus heteroclitus as a window into the molecular evolution of gene regulation. F. heteroclitus are found along the East Coast of North America, with populations distributed along a steep thermal gradient. At the extremes of the species range, populations have undergone local adaptation to their habitat temperatures. A variety of genes differ in their regulation between these populations. We have determined the mechanism responsible for changes in lactate dehydrogenase-B (Ldh-B) gene regulation. A limited number of mutations in the regulatory sequence of this gene result in changes in its expression. Both the phenotypic (increased LDH activity) and genotypic (changes in Ldh-B regulatory sequences) differences between populations have been shown to be affected by natural selection, rather than genetic drift. Therefore, even a small number of mutations within important regulatory sequences can provide evolutionarily significant variation and have an impact on environmental adaptation.

PMID:
11250554
DOI:
10.1016/s1096-4959(00)00357-2
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center