Gene expression patterns during ecdysis will also demonstrate how the genes are regulated during juvenile and adult development. Taking advantage the Daphnia genome linkage map being created in the Mike Lynch's lab, I will be able to map and define the regulatory gene, or genes, responsible for the induction of cuticular melanization in Daphnia . Once I have located this gene in one melanic lineage, I can look for the same gene, or changes in the gene, in other melanic and non-melanic lineages. The results of these experiments should provide strong clues as to how cuticular melanism evolved in the genus Daphnia and how genetic, genomic, and developmental factors interact to produce a novel phenotype. A neighbor-joining phylogenetic analysis of the genus Daphnia with the genus Scapholeberis as the outgroup.
Black dots represent melanic species.