Date of Award

2013

Document Type

Thesis

Degree Name

Bachelors

Department

Natural Sciences

First Advisor

Weber, Diana

Keywords

Conservation Genetics, Major Histocompatibility Complex, Genetic Diversity

Area of Concentration

Conservation Biology

Abstract

The major histocompatibility complex (MHC) is part of the immune system in all vertebrates, potentially providing protection from a wide range of pathogens, and thus increasing individual fitness. The insight into species ability for long-term survival is key for conservation as populations with high diversity in the immune system may have increased survival to novel pathogens and changing environments. Conversely, when diversity is lost, the ability of a species to cope with new diseases and parasites could be reduced resulting in lower survival rates and increased infection. Historically, extreme cold temperatures in polar environments have prevented an influx of pathogens, and thus species in these regions have maintained a low pathogen prevalence and load. Currently, both polar environments are warming and the environment is changing at record levels, a phenomena especially pronounced in the Arctic. To assess potential vulnerability of polar species to disease exposure, I examined genetic variation in the MHC from two polar carnivore species, the arctic fox and the southern elephant seal, and found both had moderate levels of genetic diversity. The arctic fox showed high genotypic diversity, high heterozygosity, and a large number of polymorphic sites for both loci, DRB and DQB. In contrast, the southern elephant seal had low to moderate nucleotide diversity and all loci had lower observed heterozygosity than expected, though the number of alleles was high, especially for DRB. This is notable when compared with its sister taxa, the northern elephant seal, which has almost no genetic variability. As the climate changes, a healthy immune system may increase population viability of these two polar species. It is important to understand the genetic dynamics of a species to infer its possible response to climate change and shifts in the environment, as this will increase the effectiveness of conservation efforts in a changing world.

Rights

The author has granted New College of Florida the nonexclusive right to archive, make accessible, and distribute for educational purposes this work in whole or in part in all forms of media, now or hereafter known. The copyright of this work remains with the author.

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