SUPPRESSION OF egl-13 SOX DOMAIN MUTANTS REVEALS A NOVEL FUNCTION FOR SOME MEIOTIC GENES
Open Access
- Author:
- Nelms, Brian Lewis
- Graduate Program:
- Biochemistry, Microbiology, and Molecular Biology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- June 01, 2006
- Committee Members:
- Wendy Hanna Rose, Committee Chair/Co-Chair
Zhi Chun Lai, Committee Member
Pamela J Mitchell, Committee Member
David Scott Gilmour, Committee Member
Richard W Ordway, Committee Member - Keywords:
- C. elegans
egl-13
him-8
uterine
development - Abstract:
- The gene egl-13 is needed for the proper development of the C. elegans uterine seam cell, an essential component of the egg-laying apparatus. In order to determine what other genes may be required for uterine seam cell development, a suppressor screen was performed, and two suppressors, him-8 and ku376 were discovered. I have characterized the genetic behavior of these two suppressors to gain insight into the molecular mechanism of their action. Only mutations within the C2H2 zinc fingers of him-8 are able to suppress the egg-laying and connection-of-gonad defects of egl-13 non-null mutants. I have found that wild-type HIM-8 acts in a semi-dominant fashion either upstream of or parallel to egl-13 in an antagonistic manner. The genetic behaviors of him-8 in suppression are different than its previously characterized genetic behavior in meiosis. I have shown that him-8 functions outside of the germ line and independently of its role in meiosis, revealing a novel function for him-8. Also, egl-13 may not be the only target of the him-8 suppressive function, as I have shown that some pop-1 defects can also be suppressed. ku376 also suppresses the defects of non-null egl-13 mutants, acting in a semi-dominant fashion. Whereas him-8 mutants also have a high-incidence-of-males phenotype, ku376 has no phenotype on its own. I have mapped the ku376 locus to the far left end of the fourth chromosome and have identified two candidate genes, but the molecular identity of ku376 remains unknown. While we do not know if ku376 plays any role in meiosis, I have shown that suppression of egl-13 defects can be effected by mutations in other meiotic genes beside him-8, suggested a broader role for meiotic C2H2 zinc finger proteins outside of meiosis.