A report on genetic affinities and relatedness of Agassiz’s desert tortoises (Gopherus agassizii) at opposite ends of the Coachella Valley in California

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Abstract

This report summarizes the results for mtDNA and STR genotyping of 41 desert tortoise (Gopherus agassizii) DNA samples from opposite sides of the Coachella Valley: one sample from the west side at the Mesa wind energy facility in the Whitewater Hills and the other from the mouth of Cottonwood Canyon in Joshua Tree National Park, both within the boundaries of the Coachella Valley Multiple Species Habitat Conservation Plan. Additional samples were collected from tortoises on the northern bajadas of the Orocopia Mountains and from the Santa Rosa Mountains and those results will be presented at a later time in a scientific publication. We tested samples for their mtDNA haplotype and 25 STR loci previously used in other studies. We performed assignment testing to determine the genetic affinity of each individual to the geographic region of collection. Despite apparent isolation, both populations appear to be naturally occurring and do exhibit indications of having experienced increased genetic drift (resulting in increased homozygosity, increased inbreeding or a reduction of genetic diversity). The lack of strong evidence for genetic isolation suggests that long-term maintenance of unfragmented landscapes is an important part of tortoise conservation in the region.

Publication type Report
Publication Subtype Other Report
Title A report on genetic affinities and relatedness of Agassiz’s desert tortoises (Gopherus agassizii) at opposite ends of the Coachella Valley in California
Year Published 2017
Language English
Publisher Coachella Valley Conservation Commission
Contributing office(s) Southwest Biological Science Center
Description 16 p.
Larger Work Type Report
Larger Work Subtype Other Report
Larger Work Title Coachella Valley Multiple Species Habitat Conservation Plan/Natural Community Conservation Plan—2017 Annual Report
First page 131
Last page 146
Country United States
State California
Other Geospatial Coachella Valley
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