RST Calc: a collection of computer programs for calculating estimates of genetic differentiation from microsatellite data and determining their significance


S. J. Goodman Institute of Cell, Animal and Population Biology, University of Edinburgh, Kings Buildings, West Mains Road, Edinburgh EH9 3JT, UK. Tel: +1-(0)131-650-5515; Fax: +1-(0)131-667-3210. E-mail:


RST, an analogue of FST, provides a convenient approach for estimating levels of genetic differentiation from microsatellite data. This paper examines current approaches for calculating estimates of RST and suggests a weighting scheme based on the transformation of allele sizes at loci across data sets. Combined within an analysis of variance framework this scheme yields an estimator of RST analogous to the θ estimator of FST. Software for the IBM-PC is described which carries out such calculations and assesses the significance of RST or Nm estimates using bootstrap and permutation tests.