Murray State University
Screening Out the SPAM: Using Suppressor Genetics to Identify Novel Effectors of Fertility
Institution
Murray State University
Faculty Advisor/ Mentor
Chris Trzepacz
Abstract
The biology and genetics of the nematode C. elegans makes it an attractive model organism for elucidating complex biological systems. For example, in many organisms the production of oocytes and sperm depends upon interactions between germline and somatic gonadal tissues. PAM-1, the C. elegans paralog of the human puromycin sensitive aminopeptidase, mediates a signaling pathway that participates in stimulating oocyte maturation. Mutations in pam-1 result in a reduced brood size and a dramatic increase in embryonic lethality. PAM-1 and its paralogs are conserved throughout eukaryota and participate in numerous signaling pathways. However, identification of the other components of these pathways has remained elusive. We have initiated a genetic suppressor screen to isolate and identify novel components of the PAM-1 signaling pathway. In several separate experiments, we have mutagenized over 90,000 nematode genomes and have screened the F2 generation of the mutagenized animals for alleles that suppress the pam-1 phenotype and result in a healthier and more fecund worm. From these screens we have isolated several suppressor alleles. Using classical genetic mapping techniques we have mapped one of these alleles, spam-1(akr1), to the right terminus of chromosome IV. We predict that these suppressor alleles represent novel genes in the pam-1 signaling pathway, and that identification of these suppressor alleles will provide some insight into the mechanisms that govern fertility in both C. elegans and humans.
Screening Out the SPAM: Using Suppressor Genetics to Identify Novel Effectors of Fertility
The biology and genetics of the nematode C. elegans makes it an attractive model organism for elucidating complex biological systems. For example, in many organisms the production of oocytes and sperm depends upon interactions between germline and somatic gonadal tissues. PAM-1, the C. elegans paralog of the human puromycin sensitive aminopeptidase, mediates a signaling pathway that participates in stimulating oocyte maturation. Mutations in pam-1 result in a reduced brood size and a dramatic increase in embryonic lethality. PAM-1 and its paralogs are conserved throughout eukaryota and participate in numerous signaling pathways. However, identification of the other components of these pathways has remained elusive. We have initiated a genetic suppressor screen to isolate and identify novel components of the PAM-1 signaling pathway. In several separate experiments, we have mutagenized over 90,000 nematode genomes and have screened the F2 generation of the mutagenized animals for alleles that suppress the pam-1 phenotype and result in a healthier and more fecund worm. From these screens we have isolated several suppressor alleles. Using classical genetic mapping techniques we have mapped one of these alleles, spam-1(akr1), to the right terminus of chromosome IV. We predict that these suppressor alleles represent novel genes in the pam-1 signaling pathway, and that identification of these suppressor alleles will provide some insight into the mechanisms that govern fertility in both C. elegans and humans.