Faculty Mentor: Marcia O’Connell
Student: Daniel Ferrer
This project’s goal is to determine the function of two genes that are believed to function in the early stages of development of zebrafish embryos. The two genes of interest, hnrnpab and zgc:77052-201, are the two genes that are most homologous to the squid gene in Drosophila melanogaster. In D. melanogaster, squid codes for an RNA-binding protein that localizes the product of another gene to specific areas of the egg. The presence of the localized gene product influences the dorsal/ventral patterning of the egg. The functions of the genes in zebrafish were studied this summer through a series of microinjections. The embryos were injected with morpholinos specific to those genes between the one to two cell stages and the eight cell stage. Morpholinos are small antisense molecules that are designed to block the translation of a specific mRNA. The morpholinos were injected to prevent expression of the two genes under investigation. The embryos were fixed in methanol:DMSO and stained using immunohistochemistry to determine the effects of the injection on the expression of muscle-specific myosin, which is specifically expressed in somites in the embryo. Somites are embryonic structures that, in vertebrates, eventually develop into dermis, skeletal muscle, and vertebrae, and therefore are indicators of correct dorsal patterning of the embryo. The results of the injections suggest that blocking the expression of hnrnpab and zgc:77052-201 disrupts the sharp, chevron patterning of the somites and the somite size. Therefore, these initial results indicate that the genes of interest in zebrafish may be involved in dorsal/ventral patterning and possibly homologous in function, as well as structure, to the gene in D. melanogaster.