Abstract # 12:

Scheduled for Thursday, June 17, 2010 09:30 AM-09:40 AM: Session 3 (Medallion Ballroom B) Oral Presentation


SIGNATURE OF A GENETIC BOTTLENECK DETECTED IN WILD RING-TAILED LEMURS (LEMUR CATTA) FROM SOUTHWEST MADAGASCAR

J. A. Parga1, F. P. Cuozzo2 and R. R. Lawler3
1University of Toronto at Scarborough, Department of Social Sciences, 1265 Military Trail, Toronto, Ontario M1C 1A4, Canada, 2University of North Dakota, 3James Madison University
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When an animal population experiences a decline in population size that results in a loss of genetic diversity, the genetic signature of the causative bottleneck event can be detected by analyzing allele frequencies for heterozygosity excess (a signal of a genetic bottleneck). We evaluated ring-tailed lemur samples from two sites in southwest Madagascar, Beza Mahafaly and Tsimanampetsotsa, for evidence of a genetic bottleneck. We genotyped a total of 45 individuals at 8 autosomal microsatellite loci, and tested the resultant data for a genetic bottleneck under three different mutation models: the stepwise mutation model (SMM), two-phase model (TPM), and infinite allele model (IAM). Under the highly conservative SMM, neither population showed a bottleneck. However, under the TPM (assuming 80% multistep mutations), Beza Mahafaly showed evidence of a genetic bottleneck [Wilcoxon: n=20, P<0.05], and both populations showed evidence of a bottleneck under the IAM [Wilcoxon: n1=20, n2=25, P<0.05 for both]. Although evidence of a bottleneck was found in both populations, a stronger bottleneck signal was clearly detected for Beza Mahafaly, an area which is approximately one-tenth the size of Tsimanampetsotsa and suffers from greater anthropogenic impact. In addition to signaling a recent decrease in the genetic diversity of wild ring-tailed lemurs, these data show that certain lemur populations in Madagascar are more likely than others to experience negative genetic effects from a population decline.