Cross-species amplification of microsatellite loci for nine-spined stickleback Pungitius pungitius

Abstract

Microsatellite loci of nine-spined stickleback (Pungitius pungitius) were optimized using primers originally designed for the three-spined stickleback (Gasterosteus aculeatus). Of the 57 three-spined stickleback loci tested, only 18 loci (32%) amplified a specific PCR product in the nine-spined stickleback. Further analysis for two Fennoscandian populations revealed 11 polymorphic and six monomorphic loci. The eleven polymorphic markers were optimized into two ready-to-go genotyping panels to facilitate genotyping applications, and these markers should prove useful for population genetic studies in the nine-spined stickleback. Comparison of polymorphism in the 11 loci between three- and nine-spined sticklebacks collected from the same two (lake or sea) localities revealed significantly lower polymorphism in the nine- than in the three-spined sticklebacks, and in the lake than in the sea populations of both species. Moreover, loss of polymorphism in the lake population was especially pronounced for the nine-spined stickleback (target species) as compared to the three-spined stickleback (source species). This suggests that the success of cross-species amplification may, in addition to well-known effects of e.g. species evolutionary divergence, depend on population history. © Finnish Zoological and Botanical Publishing Board 2007.