Submission Date


Document Type

Paper- Restricted to Campus Access


Biochemistry & Molecular Biology

Faculty Mentor

Rebecca Lyczak


Presented during the 24th Annual Summer Fellows Symposium, July 22, 2022 at Ursinus College.

This research was funded by a grant from the National Institute of Health.

Project Description

Puromycin-sensitive aminopeptidases (PSAs) are M1 family metalloproteases that regulate the cell cycle, fertility, and embryogenesis in many organisms. The PSA homolog found in the nematode Caenorhabditis elegans is known as PAM-1, and it cleaves the N-terminus of unknown target proteins. Mutations in pam-1 diminish embryonic hatch rates, indicating that the PAM-1 protein is necessary for embryogenesis. PAM-1 also plays roles in meiotic cell cycle progression and polarization of the anteroposterior (AP) body axis, as pam-1 mutants have been shown to experience delays in meiotic exit timing and defects in polarity establishment. Suppressor mutations in C. elegans pam-1 mutants have been shown to partially restore embryonic survival and polarity phenotypes. One novel suppressor of pam-1, spam-3(lz6), is of further interest because it has been shown to increase embryonic viability from 7.1% in pam-1(or347) mutant worms to 78.53% in pam-1(or347) mutants with the lz6 suppressor. In this study, pam-1 mutants demonstrate defects in early embryo polarity phenotypes necessary for AP axis formation that are significantly rescued in the presence of the lz6 suppressor mutation. A new strain, pam-1(or403); lz6; NMY-2::GFP was also isolated for future studies of polarity in mitosis. Though no significant differences in average meiotic exit timing were found between wildtype, pam-1(or403), and pam-1(or403);lz6, trends in increased average meiotic exit timing from wildtype to pam-1(or403);lz6 to pam-1(or403), respectively, may be observed.


Available to Ursinus community only.