Ancient conservation of trinucleotide microsatellite loci in polistine wasps

Microsatellites have proven to be very useful genetic markers for studies o f kinship, parentage, and gene mapping. If microsatellites are conserved am ong species, then those developed for one species can be used on related sp ecies, which would save the time and effort of developing new loci. We eval uated conservation of 27 trinucleotide loci that were derived from 2 specie s of Polistes wasps in cross-species applications on 27 species chosen from the major lineages of the Vespidae, which diverged as much as 144 million years ago. We further investigated cross-species polymorphism levels for 18 of the loci. There was a clear relationship between cladistic distance and both conservation of the priming sites and heterozygosity. However the loc i derived from P. bellicosus were much more widely conserved and polymorphi c than were those derived from P. annularis. The disparity in cross-species utility between these sets of loci means that caution should be used in ge neralizing from conservation rates derived from single species. We found no relationship between locus conservation or heterozygosity and GC content o f flanks, repeat motif, repeat length, or heterozygosity in the original sp ecies, which suggests that generalizations from other studies reporting suc h patterns are premature. (C) 1998 Academic Press.