Document Type

Honors Project

Publication Date



The aims of this investigation are to characterize and compare the expression pattern of several genes in two different strains of the nematode Caenorhabditis elegans and to determine whether their pattern of gene expression is dependent on the transcription factor encoded by the daf-19 gene. The design consists of creating a plasmid in which a reporter gene is ligated to the putative control region of one of several select genes from C. elegans, and injecting this purified plasmid DNA into the gonad of the hermaphrodite nematode. The progeny of the injected worms will be used in several genetic crosses to create the two transgenic strains for each reporter gene: one in which the daf-19 gene is wild type and another in which the daf-19 gene contains a mutation resulting in complete loss-of-function, a null mutation. The neural expression patterns of the reporter genes are compared in worms from the two genetic backgrounds to determine whether their expression is dependent on daf-19. Expression patterns of three genes, Y73F8A.11, C06G3.6, and K07C11.7, have been analyzed. C06G3.6 transgenic wild-type worms show expression in several neurons around the anterior bulb of the pharynx as well as in each of the vulval muscles cells and some body wall muscle. A slight decrease was noted in intensity of expression between the daf-19 null mutant and wild-type worms carrying the C06G3.6 reporter gene. K07C11.7 transgenic wild-type worms show a punctate neuronal GFP expression pattern in the ventral nerve cord as well as in nerve cell commisures along the body and in the head as well as in some nerve cell bodies around the posterior bulb of the pharynx. Also, a higher level of gfp expression in body wall muscle cells has been noted in daf-19 mutants compared to wild type worms during analysis of K07C11.7 transgenic worms, while a slightly lower level is observed in the nerve cord cell bodies. Y73F8A.11 GFP expression is observed in one motor or two (one motor and one interneuron) cell bodies in the head depending on the sex of the animal. These expression patterns are all novel and promising for further research into DAF-19 regulation.

Level of Honors

summa cum laude




Elizabeth De Stasio