Genome Duplication Of Rice (Oryza Sativa)

Genome duplication was a powerful evolutionary force and has been more important in shaping the evolution of biological novelty and complexity. In this paper, we studied (1) the rice (Oryza sativa) genome duplication; (2) the application of maximal sequence length of exact match between members from a gene family during early evolution in plant genome duplication; (3) comparison research on searching for duplicated block of plant genome. The main results follow as:1. The rice (Oryza sativa) genome duplicationWe detected the duplicate regions of rice genome using the 12 pseudomolecules of rice chromosomes by The Institute of Genome Research (TIGR, version 1.0 and 2.0) on the basis of BLASTN reciprocal best-hits between coding sequences of chromosome pairs. First, a large-scale ancient duplication in which most chromosomes involved and a recent duplication between chromosome 11 and 12 were identified based on dot plots of the one-to-one paralogous genes. Second, based on the age distribution of pairs of duplicated genes and using an effective approach to control background noise, another potentially older large-scale duplication event that predates monocot-dicot divergence was detected in the rice genome.2. The application of maximal sequence length of exact match between members from a gene family during early evolution in plant genome duplicationWe investigated the MALE changes of main gene families from four representative species (Arabidopsis thaliana, Oryza sativa, Mus musculus and Homo sapiens) during evolution. Our results indicated that MALEs were related with evolutionary time significantly during early evolution of gene families, and four curve functions between MALE and evolutionary time were created for the four species using data on their gene families, respectively. Based on the four functions, a reference table between MALE and its corresponding evolutionary time was also constructed for the four species. As an important application of our study on genome alignment, an example of study on large-scale duplication events of rice genome was illustrated.