Analysis of the genetic diversity of Bacillus thuringiensis by fAFLP

Abstract

Bacillus thuringiensis isolates obtained from seven states of Brazil were analyzed by the technique fAFLP (Fluorescent Amplified Fragment Length Polymorphism) with the objective of determining the degree of variability and the existing similarity with the genotype of ancestral strains. The genomic DNA from each isolate was double digested with the enzymes EcoRI and MseI and the resulting fragments were ligated to special adapters. Pre-selective and selective amplifications were carried out using a set of primers and the amplified fragments were taken to be electrophoretically separated in an ABI377 DNA sequencer machine. The resulting patterns were analyzed by the softwares GeneScan and Genotyper. The banding patterns yielded a number of polymorphic bands which were grouped producing a dendrogram exhibiting great similarities among the bacterial isolates and the control strains that were included in the analysis. Additional key-words: DNA fingerprinting, PCR, restriction enzymes, DNA electrophoresis