Microsatellite development and inheritance in the planarian flatworm Schmidtea polychroa

We developed four polymorphic microsatellite loci for the hermaphroditic pl anarian Schmidtea polychroa and used them to identify differences in recomb ination rate in the male and female germ line. DNA isolation protocols were optimized for tissue from adults and hatchlings. The final PCR protocols a nd profiles yielded repeatable and reliable amplification. Null alleles det ected at one locus could be avoided by redesigning one primer. Routine geno typing was established using fluorescent-labeled primers and an ABI 310 aut omated sequencer. They amplify successfully in a number of populations. The four loci are characterized by extreme within-population polymorphism, wit h 15 to 20 alleles per locus in a standard sample. All four have been submi tted to GenBank. Two loci (SpATT16, SpATT18) appeared to be coupled. From p arent-offspring comparisons, the recombination fraction could be estimated, which was significantly different for the male (c = 0.07) and female (c = 0.23) line. High overall exclusion rates for first (>0.94) and second paren t (>0.98) even with three (unlinked) loci demonstrates the suitability of t hese microsatellites for other applications such as parentage analysis.