In my Anolis work I am investigating a dewlap colour-pattern polymorphism in a Panamanian anole lizard (Anolis apletophallus) in relation to population divergence and speciation. My project aims to describe population divergence in the trait, identify the genetic architecture of dewlap traits and the loci underpinning the colour-pattern polymorphism, quantify reproductive barriers between populations and characterise patterns of genomic divergence and/or introgression between populations.
The colour-pattern polymorphism that exists across populations of Anolis apletophallus provides a useful study system to investigate trait divergence and speciation. The polymorphism in dewlap colour-pattern is discrete; male lizards have either a solid orange dewlap or a white dewlap with a basal orange spot and there are no intermediate forms. Across the species range there are populations containing only a single dewlap morph and populations containing both morphs in sympatry. There is no evidence of restricted gene flow between dewlap morphs based on microsatellite data.
Breeding experiments in the lab have revealed that dewlap colour-pattern is inherited as a mendelian dominant trait; orange is dominant to white. Crosses between lizards with different dewlap colours produces F1 offspring that are viable, but that have lower fertility when crossed with other F1 offspring or backcrossed to the parental types. Reduced fertility and variation in female preferences between populations could be reducing geneflow between the populations and contributing to the maintenance of this polymorphism.
To investigate patterns of genomic divergence and identify the loci underpinning the dewlap-colour pattern I have constructed RAD-tag libraries and sequenced theses on an Illumina Hi-Seq machine. Using this data I will characterize the patterns of genomic divergence between populations and perform a Genome-Wide Association Scan (GWAS) to identify regions of the genome associated with dewlap colour-pattern. This data analysis is in progress.
This project is funded by Marie Curie Actions
Stapley J, Wordley C, and Slate J. (2011) No evidence of genetic differentiation between Anoles with different dewlap color patterns, Journal of Heredity 102:118-124
Wordley CR, Slate J and Stapley J. (2010) Mining online genomic resources in Anolis carolinensis facilitates rapid and inexpensive development of cross-species microsatellite markers for the Anolis lizard genus. Molecular Ecology Resources 11:126-133
More pictures from Panama