Cross-species amplification, non-invasive genotyping, and non-Mendelian inheritance of human STRPs in Savannah baboons

Twenty-mine human microsatellite primer pairs were screened for their utili ty in the cross-species amplification of baboon DNA derived from both blood and feces as part of a larger study to identify paternal half sisters in a population of wild baboons (Papio cynocephalus). Forty-one percent (12/29) of the human primers successfully amplified baboon DNA. Of these 12 primer s, six amplified fragments that were both polymorphic and heterozygous (mea n number of alleles = 6, mean heterozygosity = 87%) and yielded repeatable results. However, only five of these six simple tandem repeat polymorphisms (STRPs) showed patterns of Mendelian inheritance (i.e., mothers and offspr ing shared at least one allele at each locus), and were therefore useful fo r determining relatedness between individuals. Analysis of the sixth primer revealed non-Mendelian inheritance, i.e., three of the six known mother-da ughter pairs had no shared alleles. This failure was probably due to non-sp ecific fragment amplification, and may have resulted from a different STRP locus being amplified in mother and daughter. This finding highlights the i mportance of sampling DNA from known parent-offspring pairs when screening microsatellite primers for genetic studies. Multiple, independent replicati ons of genotypes and Mendelian checks are both particularly important when using cross-species amplification or when using a low-quality source of DNA . (C) 2000 Wiley-Liss, Inc.