Comparative Inference Of Gene Conversion Between Homoeologous Chromosomes In Wheat

The wheat(Triticum aestivum)genome sequence was published in August 2018,which provided important data for wheat genome research.In this project,we used rice and diploid wheat(Aegilops tauschii;Triticum urartu)and wild emmer wheat genome to point at the possible gene conversion of some homoeologous genes in wheat and then comparative genomics analysis was performed on some homoeologous genes between subgenomes in wheat and homologous genes generated from the ancient grass common whole-genome duplication.We used the collinearity of genes existing in the genome and between different genomes,some homologous genes associated with polyploidization and species differentiation in multiple wheat genomes were identified and then the list of collinear genes was generated and constructed phylogenetic trees.The difference in topological structure between the gene tree and the expected tree inferred the possible gene conversion between some homoeologous genes in wheat,and statistically evaluated the identification of possible conversion events.Through the analysis of gene conversion between ancient duplicated genes and recent duplicated genes in wheat,it was found that the ratio of gene conversion in each subgenome is about 1% and the gene conversion ratio between different subgenomes is about 2%.Furthermore,we calculated the distribution of genes on chromosomes where gene conversion occurred,it was found that the frequency of conversion between genes near the end of the chromosome is higher.Finally,GO functional enrichment analysis was carried out on duplicated genes in wheat that had undergone gene conversion and it was found that functional genes such as the extracellular region genes tended to undergo gene conversion while cell part genes showed an evasive trend.We also found that starch synthesis genes were likely to be affected by gene conversion.The research results of the subject can increase the understanding of illegitimate genetic recombination between some homoeologous chromosomes of wheat and help to understand the stability of the genome after polyploidization.Figure 18;Table 7;Reference 51...