Molecular and genetic analysis of spermatogenesis in Caenorhabditis elegans.

Persistent Link:
http://hdl.handle.net/10150/186978
Title:
Molecular and genetic analysis of spermatogenesis in Caenorhabditis elegans.
Author:
Nogueras de Minniti, Alicia Susana.
Issue Date:
1994
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
For cells to function in a complex organism, they must differentiate and acquire their specific morphology. To study how cells achieve this I have chosen the spermatozoon of the nematode Caenorhabditis elegans. Genes involved in virtually every step of sperm development have been identified by mutations in C. elegans and these mutations dissect the process of differentiation. During spermiogenesis spherical non-motile spermatids differentiate into bipolar amoeboid spermatozoa. Chapters II and III describe the characterization of two genes that affect this differentiation. For both genes, spe-27 and spe-12, mutant hermaphrodites are sterile whereas mutant males are fertile, and spermatids only activate in response to a subset of in vivo and in vitro activators. I present a detailed genetic, phenotypic and molecular analysis of spe-27 mutants. Spe-27 maps to chromosome IV between two previously cloned genes, so I could isolate and sequence a genomic clone containing spe-27 by transformation rescue with clones from the physical map. The protein sequence predicted from the genomic and cDNA sequences shows no significant similarity with currently known proteins. Three mutant alleles were found to be two splicing defects and a missense mutation. Differential northern analysis and in situ hybridizations indicate that spe-27 is expressed in spermatocytes. I propose a model for spermatid activation in which the spe-27 gene product is a member of a signaling pathway necessary for hermaphrodite sperm activation, and present but redundant in the males. I hypothesize that the spe-12 gene product is another member of the signaling pathway necessary for hermaphrodite spermiogenesis. I isolated six new spe-12 alleles. Chapter IV describes collaborative research to characterize the spe-6 gene, which is involved in the localization of sperm-specific proteins to specialized organelles at the spermatocyte stage. The spe-6 gene shows second site non-complementation with an unlinked deficiency, which suggests the presence of interacting gene(s) over that deficiency. I also collaborated on research on the spe-26 gene, but that work is not included in this dissertation.
Type:
text; Dissertation-Reproduction (electronic)
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Molecular and Cellular Biology; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Ward, Samuel

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleMolecular and genetic analysis of spermatogenesis in Caenorhabditis elegans.en_US
dc.creatorNogueras de Minniti, Alicia Susana.en_US
dc.contributor.authorNogueras de Minniti, Alicia Susana.en_US
dc.date.issued1994en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractFor cells to function in a complex organism, they must differentiate and acquire their specific morphology. To study how cells achieve this I have chosen the spermatozoon of the nematode Caenorhabditis elegans. Genes involved in virtually every step of sperm development have been identified by mutations in C. elegans and these mutations dissect the process of differentiation. During spermiogenesis spherical non-motile spermatids differentiate into bipolar amoeboid spermatozoa. Chapters II and III describe the characterization of two genes that affect this differentiation. For both genes, spe-27 and spe-12, mutant hermaphrodites are sterile whereas mutant males are fertile, and spermatids only activate in response to a subset of in vivo and in vitro activators. I present a detailed genetic, phenotypic and molecular analysis of spe-27 mutants. Spe-27 maps to chromosome IV between two previously cloned genes, so I could isolate and sequence a genomic clone containing spe-27 by transformation rescue with clones from the physical map. The protein sequence predicted from the genomic and cDNA sequences shows no significant similarity with currently known proteins. Three mutant alleles were found to be two splicing defects and a missense mutation. Differential northern analysis and in situ hybridizations indicate that spe-27 is expressed in spermatocytes. I propose a model for spermatid activation in which the spe-27 gene product is a member of a signaling pathway necessary for hermaphrodite sperm activation, and present but redundant in the males. I hypothesize that the spe-12 gene product is another member of the signaling pathway necessary for hermaphrodite spermiogenesis. I isolated six new spe-12 alleles. Chapter IV describes collaborative research to characterize the spe-6 gene, which is involved in the localization of sperm-specific proteins to specialized organelles at the spermatocyte stage. The spe-6 gene shows second site non-complementation with an unlinked deficiency, which suggests the presence of interacting gene(s) over that deficiency. I also collaborated on research on the spe-26 gene, but that work is not included in this dissertation.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineMolecular and Cellular Biologyen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairWard, Samuelen_US
dc.identifier.proquest9517588en_US
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