Submission Date


Document Type

Paper- Restricted to Campus Access


Biochemistry & Molecular Biology

Faculty Mentor

Rebecca Lyczak


Presented during the 18th Annual Summer Fellows Symposium, July 22, 2016 at Ursinus College.

Supported by a National Institutes of Health Academic Research Enhancement Award (AREA) grant (1 R15 GM110614-01).

Project Description

Polarity establishment is an essential process in C. elegans embryonic development, and occurs prior to the first cell division. This process is initiated when the sperm-donated centrosome makes contact and triggers changes in the posterior cortex and results in an asymmetric first division. Past research in this lab has concluded that the PAM-1 aminopeptidase plays an important role in centrosome positioning. In mutants lacking functional PAM-1, cell polarity fails and a symmetric first division occurs, resulting in high embryonic mortality. Several suppressor mutations in these pam-1 mutants have been identified which rescue embryonic lethality. Each suppressor exhibits successful polarity establishment and lacks the defects seen in pam-1 mutant embryos. One such mutation is the lz5 suppressor, which has been found to raise the hatch rate of embryos in one pam-1 mutant from 2% to 36%. Identification and characterization of this suppressor could yield new information about PAM-1’s role in polarity establishment and the other proteins it interacts with. In past years, the lz5 suppressor mutation was located using single nucleotide polymorphism (SNP) mapping and whole genome sequencing was used to identify 14 candidate genes that could be lz5. This summer, RNA interference was used to identify which candidate gene is the lz5 suppressor. Furthermore, digital interference contrast (DIC) microscopy was used to observe the phenotype of wild type, pam-1 mutant, and lz5 suppressor worm strains. Preliminary results suggest that wee1.3, a dual-specificity protein kinase, is the lz5 suppressor. From this finding, we hope to further characterize the mechanism of suppression of wee1.3 and its interaction with pam-1.


Available to Ursinus community only.