C. Elegans OMA-1 and OMA-2 are Transcriptional and Translational Repressors of Germline Fate
type: CreativeWork
description: The germline is a very specialized cell lineage for the proper transmission of genetic material through many generations, to ensure flawless perpetuation of the species and life cycles. The germline lineage is set aside as early as embryogenesis and kept quiescent until germ cells are needed for adult reproduction. During C. elegans germline development global transcription is repressed in specialized, mature diakinetic oocytes of the adult animal and transcription is reactivated as zygotic transcription in the 4-cell stage embryo but only in somatic blastomeres. Global transcription is kept repressed by PIE-1 in germline precursors beginning with 4-cell stage to protect germ lineage from inappropriate somatic differentiation pathways. During my graduate studies, I investigated the redundant roles for two CCCH type RNA binding zinc finger proteins OMA-1 and OMA-2 during C. elegans germline development and early embryogenesis. Previously, OMA proteins were shown to be required for oocyte maturation but they were not assigned any molecular functions. My thesis demonstrates transcriptional repression function of OMA proteins in newly fertilized embryos and translational repression functions during oogenesis. I showed that OMA-1/2 are redundantly required for global transcriptional repression before the onset of zygotic transcription in the 1-cell and 2-cell stages of C. elegans embryos by interacting with and sequestering in the cytoplasm TAF-4, a highly conserved essential basal transcription factor. Nuclear enrichment of TAF-4 requires interaction with another transcription factor TAF-12. OMA-1 competes with TAF-12 to interact with and change subcellular localization of TAF-4, in order to displace TAF-4 away from nuclei and prevent transcriptional initiation. I showed that interaction of OMA-1 and TAF-4 is regulated by MBK-2 phosphorylation at oocyte to embryo transition. My data suggest a model in which MBK-2 phosphorylated embryonic OMA-1 can change TAF-4 subcellul…
abstract: The germline is a very specialized cell lineage for the proper transmission of genetic material through many generations, to ensure flawless perpetuation of the species and life cycles. The germline lineage is set aside as early as embryogenesis and kept quiescent until germ cells are needed for adult reproduction. During C. elegans germline development global transcription is repressed in specialized, mature diakinetic oocytes of the adult animal and transcription is reactivated as zygotic transcription in the 4-cell stage embryo but only in somatic blastomeres. Global transcription is kept repressed by PIE-1 in germline precursors beginning with 4-cell stage to protect germ lineage from inappropriate somatic differentiation pathways. During my graduate studies, I investigated the redundant roles for two CCCH type RNA binding zinc finger proteins OMA-1 and OMA-2 during C. elegans germline development and early embryogenesis. Previously, OMA proteins were shown to be required for oocyte maturation but they were not assigned any molecular functions. My thesis demonstrates transcriptional repression function of OMA proteins in newly fertilized embryos and translational repression functions during oogenesis. I showed that OMA-1/2 are redundantly required for global transcriptional repression before the onset of zygotic transcription in the 1-cell and 2-cell stages of C. elegans embryos by interacting with and sequestering in the cytoplasm TAF-4, a highly conserved essential basal transcription factor. Nuclear enrichment of TAF-4 requires interaction with another transcription factor TAF-12. OMA-1 competes with TAF-12 to interact with and change subcellular localization of TAF-4, in order to displace TAF-4 away from nuclei and prevent transcriptional initiation. I showed that interaction of OMA-1 and TAF-4 is regulated by MBK-2 phosphorylation at oocyte to embryo transition. My data suggest a model in which MBK-2 phosphorylated embryonic OMA-1 can change TAF-4 subcellul…
author: Ozkan, Tugba Guven
language: en
keywords: Micronucleus, Germline, Caenorhabditis elegans Proteins, Carrier Proteins
date published: 2010-07-12T17:49:33Z
date modified: 2026-07-24T05:52:15Z
provider: University of Texas Southwestern Medical Center
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Texas Southwestern Medical Center

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property ID: Handle
value: https://hdl.handle.net/2152.5/378