Estudo genético de duas populações de Odontesthes bonariensis através de marcadores microssatélites.

Abstract

Divergency and genetic variability of two populations (Brazil and Argentina) were identified through polymorphism of six microsatellite markers. Eighty Five animals from the two populations were studied, 40 animals collected from Chascomus lake in Buenos Aires, Argentina and 45 from Chasqueiro Dam in Arroio Grande, Rio Grande do Sul, Brazil. The collected material was muscle and caudal fin fragments, stored in 95% ethanol and kept at -20 ºC. Three different protocols for DNA extraction were tested: 1) Phenol Chloroform; 2) Sodium chloride 3) Ammonia acetate (modified Sodium chloride). Six microsatellite loci were analyzed by allelic frequency, observed heterozygosis, expected genetic diversity according to Hardy-Weinberg equilibrium, number of alleles per locus, percentage of polymorphic loci and Wright fixation. The results showed that the microsatellites analyzed presented high polymorphism. The number of alleles varied from 4 to 15. A total of 49 alleles were obtained from all the samples. Fst value between the two populations was 0.1303, that is, the populations presented moderate genetic differentiation (P<0.05). It was concluded that due to the high polymorphism analyzed in the six microsatellite loci, they can be an efficient tool for genetic variation studies of O. bonariensis and the significant genetic differentiation in the populations analyzed can provide basis for further genetic improvement programs.