The isolation of a Distal-less gene fragment from two molluscs.

The transcription factor, Distal-less, and its orthologues (e.g. DLL/Dlx) are best known for their roles in proximo-distal and nervous system patterning as well as for their use in inferring the evolution of limbs and other proximo-distal structures. However, evolutionary applications to non-model taxa have primarily employed a polyclonal antibody, and sequence data are generally lacking. We have designed a degenerate PCR primer set specific to the recovery of a Distal-less gene fragment, and present sequence data for two bivalve molluscs, Crassostrea gigas and Nutricola sp. These sequences represent the first Distal-less homologs isolated from lophotrochozoan taxa.