Microsatellite DNA analyses of four Alouatta species (Atelidae, Primates): Evolutionary microsatellite dynamics

We discuss the evolution of nine microsatellite DNA markers in four Alouatta species (howler monkeys; A. palliata, A. seniculus, A. macconnelli, and A. caraya) as well as evolutionary population parameters. There are five main findings from this study: 1. Four microsatellite central moments (mean, variance, skewness, and kurtosis) exhibited different distributions among species, with A. palliata being the most differentiated. This may suggest that central moments provide important phylogenetic signals. 2. The "As is" bayesian method had the best percentage of classification (86.15%) of the assignment analyses. A. seniculus was the most incorrectly classified of all Alouatta species, which may suggest that some of their multigenotypes are original and that this species may be in the origin of other Alouatta species. 3. A. seniculus and A. caraya showed the highest and lowest effective numbers respectively. 4. Only 9% of the detected microsatellite mutations were multi-step and, therefore, the majority of the mutations were of uni-step origin (91%). D5S117 was the unique microsatellite that clearly showed a multi-step mutation model. Different microsatellites frequently had different mutation rates per generation. An average estimate value of 7 x 10^-5 did not support Quaternary refuges as sufficiently important for the molecular evolution of Alouatta. 5. All but two of the microsatellites (D14S51, diversifying selection and D8S165, constrictive selection) behaved neutrally.