ABSTRACT
Genetic variability is one of the important criteria for species conservation decisions. This study aimed to analyze the genetic diversity and the population differentiation of two natural populations of Arapaima gigas, a species with a long history of being commercially exploited. We collected 87 samples of A. gigas from Grande Curuai Lake and Paru Lake, located in the Lower Amazon region of Amazônia, Brazil, and genotyped these samples using a multiplex panel of microsatellite markers. Our results showed that the populations of A. gigas analyzed had high levels of genetic variability, which were similar to those described in previous studies. These two populations had a significant population differentiation supported by the estimates of FST and RST (0.06), by Bayesian analysis (K = 2), and by population assignment tests, which revealed a moderate genetic distance.
Subject(s)
Fishes/genetics , Genetic Variation , Microsatellite Repeats , Animals , Bayes Theorem , Brazil , Evolution, Molecular , Fishes/classification , Genetics, PopulationABSTRACT
The tambaqui, Colossoma macropomum, native to Brazil, is widely used in aquaculture systems. We developed a multiplex PCR panel for this species, comprising 12 microsatellite loci. This panel was used to genotype 73 specimens collected from Juruti, a city in the Brazilian Amazon. The mean number of alleles per locus was 8.8, the mean observed heterozygosity was 0.76, and the combined power of discrimination and the combined power of exclusion were 0.99999999999999993 and 0.999991762, respectively. We observed no significant deviation from Hardy-Weinberg equilibrium in this population. All amplified alleles were clearly typed, and easily interpretable results were obtained. This method will be useful for paternity analysis, population genetics and conservation studies, as well as for selective breeding programs for C. macropomum.
Subject(s)
Characidae/genetics , Microsatellite Repeats/genetics , Multiplex Polymerase Chain Reaction/methods , Alleles , Animals , Aquaculture , Gene Frequency , Genetic Variation , Genetics, Population , GenotypeABSTRACT
The aim of the present study was the development of a multiplex genotyping panel of eight microsatellite markers of Arapaima gigas, previously described. Specific primer pairs were developed, each one of them marked with either FAM-6, HEX or NED. The amplification conditions using the new primers were standardized for a single reaction. The results obtained demonstrate high heterozygosity (average of 0.69) in a Lower Amazon population. The multiplex system described can thus be considered a fast, efficient and inexpensive method for the investigation of genetic variability in Arapaima populations.
Subject(s)
Fishes/genetics , Genetic Variation , Microsatellite Repeats/genetics , Polymerase Chain Reaction/economics , Polymerase Chain Reaction/methods , Alleles , Animals , Brazil , DNA Primers/chemistry , Genetic Markers , Genotype , Heterozygote , Polymorphism, Genetic , Reproducibility of Results , Time FactorsABSTRACT
The aim of the present study was the development of a multiplex genotyping panel of eight microsatellite markers of Arapaima gigas, previously described. Specific primer pairs were developed, each one of them marked with either FAM-6, HEX or NED. The amplification conditions using the new primers were standardized for a single reaction. The results obtained demonstrate high heterozygosity (average of 0.69) in a Lower Amazon population. The multiplex system described can thus be considered a fast, efficient and inexpensive method for the investigation of genetic variability in Arapaima populations.