Submission Date


Document Type

Paper- Restricted to Campus Access



Faculty Mentor

Rebecca Lyczak


Presented during the 17th Annual Summer Fellows Symposium, July 24, 2015 at Ursinus College.

Project Description

Cell polarization is responsible for proper cell function, axis formation, and viability. In the single-cell Caenorhabditis elegans, anteroposterior polarity is triggered by the sperm donated centrosome contacting the posterior cortex. This causes a number of changes in the cell including protein localization, cortical flows, and pseudocleavage. While the importance of the centrosome is known, it remains largely unclear how centrosome positioning is achieved. The PAM-1 aminopeptidase is required for centrosome positioning at the cortex and proper axis polarization. Embryos of pam-1 mutants fail to polarize and exhibit high rates of lethality. Through suppressor screening, our lab has identified 5 suppressors (lz1-5) of pam-1 that significantly increase hatch rates. Using DIC microscopy, we have been able to examine each suppressor rescuing the polarity defects associated with pam-1 mutants. My research this summer has focused on mapping the suppressor lz4 through SNP mapping and whole genome sequencing. I have been able to narrow down the location of lz4 to a small portion of chromosome 1 using SNP mapping and I have generated several new mapping lines to validate my research. When whole genome sequencing is completed, the exact chromosomal location and mutated gene will be determined. I am also examining lz4 without the pam-1 mutation to see if it has its own phenotype. Further research on PAM-1 and its suppressors will provide identification of PAM-1 target proteins and other factors involved in centrosome positioning.


Available to Ursinus community only.