Submission Date


Document Type

Paper- Restricted to Campus Access




Rebecca Lyczak

Committee Member

Simara Price Telesford

Committee Member

Lisa Grossbauer

Department Chair

Rebecca Lyczak

Project Description

The nematode worm, Caenorhabditis elegans, is a known model organism in developmental biology and genetics. We use this model to understand the events happening in the early embryo. The framework of any organism is the cytoskeleton, which holds together the interior contents of the cell and works with the cell to polarize and set up the body axis. The purpose of understanding the cytoskeleton is to learn about the key factors in the development and what processes and genes are needed to make the embryos viable. The aminopeptidase, PAM-1, is an important regulator of the cytoskeleton, and learning about how it functions in the cytoskeleton is important. An efficient way to learn about the function of genes is to use RNA interference to inactivate the gene and study the resulting phenotype. Two principal genes known to be crucial for the cytoskeleton are pfn-1, and cyk-1. These two genes each function in cytoskeletal regulation and are required for the normal development of the C. elegans. In order to see if PFN-1 and CYK-1 interact with PAM-1 in the early embryo, each gene was inactivated in wild-type and pam-1 mutants and the embryos were imaged for the presence of pseudocleavage, blebbing, and symmetric division - signs of a functional cytoskeleton. The data was compared to that of a wild-type embryo and a pam-1 mutant embryo. When tested, it was seen that both pfn-1(RNAi) and cyk-1(RNAi) have defects in division rate that are suppressed by pam-1 mutations. This shows the importance of these two genes for cytokinesis, but that they are not necessary in the absence of PAM-1. It was also seen that in pfn-1(RNAi), there is an enhanced symmetrical division phenotype seen in pfn-1 (RNAi) pam-1 mutants, showing that PFN-1 and PAM-1 further interact during cytokinesis. We also found that CYK-1 is needed for abnormal blebbing seen in the absence of PAM-1. The results of this study will help us understand the functions of different cytoskeletal genes. These conclusions can then be used to create pathways,, to learn how these developmental genes might interact with other genes in the cell. The developmental functions of genes related to the aminopeptidase in the cytoskeleton of C. elegans can be compared to that of the pam-1 human ortholog.