Dissertation/Thesis Abstract

Evolution of the SEPALLATA genes, leafy hull STERILE1 and Oryza sativa MADS5 and their roles in regulating grass floral development
by Christensen, Ashley Rae, M.S., California State University, Long Beach, 2009, 106; 1472286
Abstract (Summary)

SEPALLATA (SEP) genes are key transcriptional regulators which act as cofactors with other floral organ identity genes during inflorescence development. Duplication events within developmental gene lineages followed by functional partitioning or diversification have likely contributed to the diversification of floral morphologies. To investigate the developmental and evolutionary roles of the SEP genes, LEAFY HULL STERILE1 (LHS1)-like and Oryza sativa MADS5 (OsMADS5), I used phylogenetic, comparative RNA expression and molecular evolutionary analyses. These results demonstrate the LHS1/OsMADS5 gene duplication event occurred at the base of grasses and the gene paralogs LHS1 and OsMADS5 have subsequently been partially subfunctionalized among grass species. Expression data of LHS1-like genes suggest the outer floral whorls of non-grass monocots and the grass palea and lemma, and bracts 6-8 of Streptochaeta are homologous. Additionally these results suggest tubercles evolved in the rice genus and are correlated to a novel insertion in the LHS1 protein sequence.

Indexing (document details)
Advisor: Malcomber, Simon
Commitee:
School: California State University, Long Beach
School Location: United States -- California
Source: MAI 48/02M, Masters Abstracts International
Source Type: DISSERTATION
Subjects: Molecular biology, Genetics
Keywords:
Publication Number: 1472286
ISBN: 9781109472264
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