My research is focused on identifying genes crucial to the development of the zebrafish lens and retina, by the molecular genetic analysis of eye morphological mutants identified by chemical mutagenesis. Our current characterization centers around the zebrafish lens opaque (lop) mutant. The mutant phenotype is characterized by the macroscopic appearance of a lens cataract at 7dpf; earlier developmental time points show no phenotype. Histological and immunohistochemical analysis revealed that lop mutants accumulate proliferating cells in the anterior ocular chamber that impede light passage through the lens. Interestingly, lop mutants also exhibit rod and cone photoreceptor degeneration. Mutation mapping identified the genomic region that harbors the lop mutant gene. A variety of molecular genetic techniques including morpholino mediated knockdown, phenotype rescue experiments, as well as complementation analysis are being used in an attempt to identify the mutant gene responsible for the observed phenotype. Future analysis will include in situ hybridization to localize lop gene transcripts as well as the generation and characterization of an antibody that is specific to the gene product of interest. This traditional forward genetics approach will reveal genes that are critical for proper development of the zebrafish eye.
