genetic variation in two polymorphic
systems in marine snail, Littorina
The previous PhD project focused on genetic variation in populations of Littorina
saxatilis living in heterogeneous environment. The main goal of the study was the effect of ecological barriers on neutral and adaptive genetic variation. Two systems of polymorphism associated with specific habitats at very small spatial scale are found in this snail. One is exposed and sheltered morphs from rocky and boulder shores and another is Aat (aspartate aminotransferase) allele cline between low and high levels of exposed rocky shore. The species lacks larvae in life cycle and adult snails do not migrate for long distance. Since this same ecomorphs are found in remote populations of this species we probably deal with the case of parallel evolution.
Genetic structure of population was studied by estimation of gene flow based on neutral markers (microsatellites) and mollusc migration. In case of Aat polymorphism we were also interested in its adaptive role and maintaining mechanisms. So, we planed to look at the selection in artificial populations, the functional difference between allozymes and DNA sequencing of the gene from geographically remote populations.
This project was funded by Swedish Science Research Council.
my personal homepage