Biology ETDs

Publication Date



Gene duplication plays a significant role in the evolution of novel function. Investigations concerning the genomic features of young gene duplicates can enhance our understanding of the nature of gene duplicates at inception and their fates over evolutionary time. Previous analysis of young gene duplicates in Caenorhabditis elegans has revealed genomic features of evolutionarily young gene duplicates with respect to structure, span, location and orientation of paralogous genes. The analysis of young gene duplicate pairs in Caenorhabditis briggsae provides insight into the characteristics of gene duplication in another member of the genus Caenorhabditis. The identification of 376 evolutionarily young gene duplicate pairs with less than 10% sequence divergence at synonymous sites and subsequent exploration of certain genomic, structural, and evolutionary features enhances our understanding of gene duplication in eukaryotic species. The mean duplication span of 3.6 kb in young C. briggsae gene duplicates is large compared to the mean transcript length of 2.7 kb. The relatively large size of a gene duplicate likely contributes to the abundance of structurally complete C. briggsae gene duplicates. The majority of very young duplicates (KS = 0) are in direct orientation on the same chromosome. Though evolutionarily older gene duplicates (0 < KS ≤ 0.10) tend to remain on the same chromosome, they are more likely to be in inverse orientation. Analysis of selective constraints acting on C. briggsae paralogs reveals that the majority of young duplicates are under weak purifying selection regardless of duplication structure. Here I show that, despite its relatively close evolutionary proximity to C. elegans, gene duplicates in C. briggsae exhibit some strikingly unique genomic characteristics.

Project Sponsors

National Science Foundation




Gene Duplication, Caenorhabditis briggsae

Document Type


Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

Bergthorsson, Ulfar

Second Committee Member

Natvig, Don