Development of microsatellite markers for six Tetranychus species by transfer from Tetranychus urticae genome.

Microsatellite markers are frequently used to explore the population genetic structure of organisms. Spider mites (genus Tetranychus) are important agricultural pests. Several markers have been developed for T. urticae, but for other spider mites, few such markers are available, hampering studies of their population genetics. In this study, we developed and characterized microsatellite markers for six non-model spider mite species (T. truncatus, T. kanzawai, T. ludeni, T. piercei, T. phaselus and T. pueraricola) by cross-species amplification of markers in the T. urticae genome, in order to better understand the population structure of Tetranychus species. Among 228 screened loci, many were polymorphic, including 13 loci in T. urticae, 11 loci in T. truncatus, 15 loci in T. pueraricola, 23 loci in T. kanzawai, 19 loci in T. piercei, 11 loci in T. phaselus and 9 loci in T. ludeni. Sequence analysis determined that the fragment length variations of the transferred microsatellites were mainly due to the variations of the numbers of repeats. These new microsatellite markers should be useful for studying the population genetics of the seven Tetranychus species.