Allelic variation analysis in genes of economic importance among hom(oe)ologous regions of sugarcane (Saccharum spp.) genome

Abstract

Sugarcane plantation bears a high economic importance, due to sugar and ethanol production, and Brazil is world's major producer of sugarcane. Modern sugarcane cultivars are interspecific hybrids (Saccharum officinarum x S. spontaneum), with polyploid and aneuploid genomes, making it difficult to construct genetic maps and to detect QTLs (Quantitative Trait Loci). The knowledge of the variations in the nucleotide sequences of different alleles enables information achievement of inter and intra genotypes variation within a species. An efficient technique to access allelic variation between homologous loci in a species is the sequencing of BAC (Bacterial Artificial Chromosomes) clones bearing specific genic loci of interest. Thereby, this project aims to discover and analyze allelic polymorphisms among sugarcane hom(oe)ologous chromosomic regions and compare their allelic organization, using genes that encode for a DnaJ and a Trehalose-6-phosphate synthase/phosphatase proteins. SNPs (Single Nucleotide Polymorphisms) identified will be used to evaluate the expression of specific haplotypes and can be integrated in genetic maps that are being developed. The analysis of these regions combined with FISH (Fluorescent in Situ Hybridization) technique will allow the physical localization of the genes. In sugarcane the identification of specific allelic expression may explain the expression mechanisms of each allele dose. (AU)