Bioen Sugarcane BAC Sequencing Project

Marie-Anne Van Sluys, Departamento de Botanica IB-USP

Polyploid genomics is an active field of research with relevance to both plant biology and evolution. Massive genomic sequencing has shown that gene structure and gene order is highly conserved among plants. Orthology is a powerful concept that has enabled the identification of the common ancestral origin of chromosomal regions from different species. The mechanisms involved in rearrangements within and among chromosomes are largely unknown. Differences between the maize and sorghum genomes are largely due to differential expansion of transposable elements. Given that the genome size of the R570 hybrid is estimated to be 10 Gb, the 300 BAC sequences released represent about 0.3 % (roughly 30 Mb) of the polyploid genome, or 1.3% of the monoploid complement. Analysis of the repetitive component of these sequences determined that approximately 52% of the total sequence is repeats, 51% TEs and 0.6% satellite repeats. The most frequent repeats identified were LTR retrotransposons followed by DNA transposons and non-LTR retrotransposons. As expected, 20-25nt small RNAs mapped to most of the repetitive sequences, but with 3-fold more 23-25 nt small RNAs in comparison with 20-22 nt small RNA sequences. In terms of gene content 1400 putative coding regions were identified, which corresponds to a gene density of six coding regions in each 100 Kbp. Predicted genes match to approximately 4.64 % of the unigenes described in the publicly available sugarcane transcriptome database. The current work provides valuable information regarding gene, TE content and genomic information of this economically relevant crop. 

Title: Bioen Sugarcane BAC Sequencing Project

mavsluys@usp.br

First author

Presenting Author:

Marie-Anne Van Sluys

mavsluys@usp.br