Genomic microsatellites as evolutionary chronometers: a test in wild cats

Area of Science:

• Population Genetics
• Genomics
• Conservation Biology

Background:

• Nuclear microsatellite loci are valuable population genetic markers due to high polymorphism and genomic abundance.
• Previous limitations in microsatellite interpretation stemmed from uncertainties in mutation rates and ascertainment bias.
• Understanding demographic history is crucial for effective conservation of endangered feline species.

Purpose of the Study:

• To assess genomic diversity patterns using microsatellite loci in cheetahs, lions, and pumas.
• To evaluate the utility of microsatellite diversity measures in reflecting historical population bottlenecks and founder effects.
• To develop genomic estimates for time intervals following founder events in these felid populations.

Main Methods:

• Analysis of genomic diversity across ninety feline microsatellite loci.
• Characterization of previously defined populations of cheetahs, lions, and pumas.
• Calculation of microsatellite diversity measures: heterozygosity, allele reconstitution, and allele size variance.

Main Results:

• Microsatellite diversity measures (heterozygosity, allele reconstitution, variance) indicated historical population bottlenecks and founder effects.
• The rate of new allele reconstruction and increase in microsatellite allele size variance correlated with demographic history.
• Genomic estimates placed founder events at approximately 12,000 years ago for cheetahs, 10,000-17,000 years ago for North American pumas, and 1000-4000 years ago for Asiatic lions.

Conclusions:

• Microsatellite markers provide valuable, albeit variable, indicators of past demographic events in feline populations.
• The study successfully estimated time intervals since founder events using microsatellite mutation and variance rates.
• These findings enhance our understanding of feline population genetics and inform conservation strategies.