Publication Date

2014

Document Type

Honors Thesis

Department

Biological Sciences

Keywords

Genetic transformation, Bacteria, Animals, Metazoa, Antibody diversity, Sequestration (Chemistry), Lateral gene transfer, Horizontal gene transfer, Germ line, Sequestration

Abstract

Lateral Gene Transfer (LGT) has long been known to be a major contributor to genome innovation and evolution in bacteria, but remains understudied in animals. Typically, it's suggested that the evolution of a sequestered germ line in metazoa creates a nigh insurmountable obstacle to LGT, but this assumption is yet to be tested. Though studies discovering evidence of LGT in certain animal genomes are beginning to emerge, none have studied LGT rates in early-diverging animals lacking a sequestered germline nor have any attempted to describe the patterns of LGT across the metazoan clade. Here, we show that analyses of single-gene phylogenies built from publically available sequences from over 1239 taxa across all three domains enable estimation of lateral gene transfer events in animal evolutionary history. The results of these analyses show a three-fold difference between the number of genes laterally transferred into bilaterian animals and the number of genes transferred into early-diverging animals without a sequestered germline, providing supportive evidence that a sequestered germline does indeed influence the rate of LGT.

Language

English

Comments

100 pages : color illustrations. Honors Project-Smith College, 2014. Includes bibliographical references (pages 26-29)

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