Sexagem molecular em aves via PCR- avaliação de três técnicas de extração e DNA

Abstract

Brazil has one of the wealthiest avifauna in the world. It is estimated that a half of the birds don’t have sexual dimorphism, that when occur, is generally subtle and could only be present in sexual maturity. All this reasons illustrate why the avian sex identification is important. This study evaluated not only the time of conservation of the DNA after extraction, but also the bird sex identification molecular analysis method using three different techniques of DNA extraction from feathers and blood. It was utilized the allele-specific primer pair P2/P8, within the CHD gene, located in the bird sexual chromosomes (Z e W), by means of the polymerase chain reaction (PCR) technique. The introns extension method of gene CHD (chromium-helicase-dependent) was chosen. The eletrophoretic result demonstrated two alleles for the females, being, therefore, heterogametics (ZW), while in the males, just one, homogametics (ZZ). Results demonstrated that there is variation between the sizes of the stand pairs (bp) between species: 246 to 396 pb for allele Z and 412 to 254 pb for the W. The three techniques of DNA extraction were efficient to all the 15 species analyzed. However the methodology using DNA extracted from the blood harvested in filter paper got better results taking into consideration the extraction time and conservation of the DNA, as well as the final cost of the technique. The results disclosed the presence of 71 males (49.31%) and 73 females (50.69%), totalizing 144 birds. This situation proposes casual deviations, Test χ2 (p>0.05). The studied variable was presented as dicotomic form part of an sampling universe. These data show that this technique is efficient and safe for the bird sexual determination.