The 14 species of Darwin finches display impressive variation in beak morphology associated with the exploitation of a variety of ecological niches. Dr. Abzhanov et al. found that the level and timing of expression of Bone morphogenic factor 4 (Bmp4) in the distal mesenchyme of the upper beaks strongly correlated with broader and deeper beaks, characteristic of the seed-eating Ground Finches. I am now cloning and analyzing BMP4 from several key species of Darwin’s Finches to detect species specific changes and patterns that could be related to beak morphology. I also study cis-regulation of Bmp4 during craniofacial development in the chicken model system using a reporter vector electroporated into neural crest cells and focusing on area upstream of Bmp4 that remained highly conserved among higher vertebrates.
African seedcrackers, just as Darwin’s finches do, display different morphs of beak in relation to their feeding behavior. I am trying to characterize the genetic loci responsible for bill size in African seedcrackers, in collaboration with Tom Smith (UCLA).