Year of Publication

2016

Degree Name

Master of Science (MS)

Document Type

Master's Thesis

College

Arts and Sciences

Department

Biology

First Advisor

Dr. Jeramiah Smith

Abstract

The sea lamprey (Petromyzon marinus) undergoes programmed genome rearrangements (PGRs) during early development that facilitate the elimination of ~20% of the genome from the somatic cell lineage, resulting in distinct somatic and germline genomes. To improve our understanding of the evolutionary/developmental logic of PGR, we generated computational predictions to identify candidate germline-specific genes within a transcriptomic dataset derived from adult germline and the embryonic stages encompassing PGR. Validation studies identified 44 germline-specific genes and characterized patterns of transcription and DNA loss during early embryogenesis. Expression analyses reveal that several of these genes are differentially expressed during early embryogenesis and presumably function in early development of the germline. Ontology analyses indicate that many of these genes play known roles in germline development, pluripotency, and oncogenesis (when misexpressed). These studies provide support for the theory that PGR serves to segregate molecular functions related to germline development/pluripotency in order to prevent their potential misexpression in somatic cells. This larger set of eliminated genes also allows us to extend the evolutionary/developmental breadth of this theory, as some deleted genes (or their gnathostome homologs) appear to be associated with the early development of somatic lineages, perhaps through the evolution of novel functions within gnathostome lineages.

Digital Object Identifier (DOI)

http://dx.doi.org/10.13023/ETD.2016.265

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