Genetic Basis of Fin Diversity
One of the most intriguing questions in biology is the evolutionary mechanism of morphological novelties and diversity in a variety of environments. The mechanisms of evolutionary and developmental constraints also remain elusive. Paired fins show extreme disparity in shape and size, as exemplified by the fins of extinct and extant cartilaginous and bony fish. Among them, skate (Leucoraja erinacea) unique fin is a striking example of novelty. In skates, the pectoral fin develops cranially and fuses with the flattened head, resulting in a body adapted to benthic life. To determine the molecular mechanisms of skate fin morphogenesis, we use a combination of RNA-sequencing, in situ hybridization, and functional genomics. The posterior portion of the skate pectoral fin has a gene expression profile that is composed of a canonical genetic module as noted in tetrapods. In contrast, the anterior portion of the fin extends cranially by a non canonical genetic module. For this research, we work at the Marine Biological Laboratory in Woods Hole, Massachusetts (2014 MBL research awardee), where we manipulate skate eggs, including injections, cell labeling and implantations.
Currently, collaboration with Skate Genome Consortium is in progress to understand the genetic basis of skate unique body development.
Nakamura T et al.
Molecular mechanisms underlying the exceptional adaptations of batoid fins.
Proc Natl Acad Sci U S A. 2015