57º Congresso Brasileiro de Genética Resumos do 57º Congresso Brasileiro de Genética • 30 de agosto a 2 de setembro de 2011 Centro de Convenções do Hotel Monte Real Resort • Águas de Lindóia • SP • Brasil www.sbg.org.br - ISBN 978-85-89109-06-2 163 Analysis of genetic population structure of the blue shark, Prionace glauca (Chondrichthyes, Carcharhinidae) in Brazilian coast using microsatellite markers Ussami, LHF1; Mendonça, FF1; Pereira, LHG1; Teixeira, AF1; Oliveira, C1; Gadig, OBF2; Foresti, F1 Laboratorio de Biologia e Genética de peixes, Instituto de Biociências de Botucatu, Departamento de Morfologia UNESP. 2Laboratório de Pesquisa em Elasmobrânquios, Campus Experimental do Litoral Paulista - UNESP. [email protected] 1 Keywords: Conservation, Clasmobranches, Microsatellite, Genetic structure, Prionace glauca With global distribution, the blue shark occurs in the oceanic-epipelagic area of the Brazilian coast, being an important economic resource ﬁsheries, since it represents about 60% of sharks caught by ﬂeets that operate industrial longline. However, knowledge about its population status remains unknown, primarily from a genetic standpoint. For the ﬁsheries segment the identiﬁcation and management of different stocks are essential for the direct relation to the total productivity and sustainable use of resources. In this respect, microsatellite markers have been widely used in the studies of ﬁsh populations, with inferences about conservation and species management, migration patterns, differentiation of natural and cultured stocks, reproductive systems and fragmentation habitats effects. Aiming to analyze the genetic populations structure of the blue shark found off in the Brazilian coast, samples caught in Rio Grande do Sul (n = 33), São Paulo (n = 33) and Rio Grande do Norte (n = 30) were analyzed using 8 polymorphic microsatellite loci. The tests were conducted via PCR and the fragments visualized on 6% polyacrylamide gel, and genotyping performed using Kodak Digital Science 1D program. The number of alleles per locus, expected and observed heterozygosities, Hardy-Weinberg equilibrium (HWE) and inbreeding coefﬁcient (Fis) were obtained with the program POPGENE v.1.32 and to the populations structure analysis, the Arlequin3.11 was used. The observed heterozygosity showed an average of 0.4341 and 0.5659 to the expected heterozygosity, as well as, being 29.50 the average number of alleles observed. The average number of effective alleles was 15.74 with coefﬁcient of inbreeding (Fis) presenting a variation of 0.1855 to 0.6450. The FST índex found was 0.0506 (P<0,00001), indicating a moderate population structure in comparisons between regions (Rio Grande do Norte, São Paulo and Rio Grande do Sul). The index of genetic structure found in the samples studied may suggest the existence of two populations of the species in South America. However, to determine the boundaries of these populations, and its application in ﬁshery management plans, more comprehensive sampling are being performed. Financial supports: FAPESP; CNPq e CAPES.