2018-07-062018-07-062006OKAMOTO, H. T. S.; SOARES, C. M. A.; PEREIRA, M. Comparative analyses of the structure of the 1,3-Beta glucan synthase gene in Paracoccidioides brasiliensis isolates. Genetics and Molecular Research, Ribeirão Preto, v. 5, n. 2, p. 407-418, 2006.1676-5680http://repositorio.bc.ufg.br/handle/ri/15354The evolutionary origin and significance of spliceosomal introns have been the subject of many investigations. Two theories, “in- trons-early” theory and “introns-late” theory, have been proposed to explain the evolution of introns in eukaryotic genes. Intron position is generally conserved in paralogue and orthologue genes. Some introns occur at similar but not necessarily identical positions in homologous genes, which were separated by great evolutionary distances. This event can be explained by insertion, loss or movement of the intron over short distances. Intron loss and gain events are unique in evolution and can be useful as markers for phylogenetic analyses. The insertion of introns at an identical position suggests a common ancestor gene. Here we ana- lyzed, using PCR and RT-PCR, the structure of the 1,3-β-glucan syn- thase gene (FKS) in several clinical isolates of Paracoccidioides bra- siliensis (Pb): isolates Pb 01, Pb 4940, Pb 8515, Pb 8311, Pb 8334, Pb 4268, Pb 1668, and Pb E. Our results showed that seven of the isolates examined showed identical structures concerning the position of introns in PbFKS1. PbFKS4940 showed the intron described at the 3’ end and had lost that one at the 5’ end. The presence of the PbFKS4940 tran- script suggests that it could be a functional gene. These data suggest a divergent evolution for introns with regard to the 1,3-β-glucan synthase gene in P. brasiliensis isolates.engAcesso AbertoParacoccidioides brasiliensisGene structureIntron evolution1,3-β-glucan synthaseComparative analyses of the structure of the 1,3-Beta glucan synthase gene in Paracoccidioides brasiliensis isolatesArtigo