Construction Of A Methylation Filtration Library And Bioinformatics Analysis Of Hevea Brasiliensis

The rubber tree (Hevea brasiliensis) is an economic woody crop in family euphorbiaceae. And natural rubber is an important irreplaceable strategic matter to development of our country. With the rapid development of economy and society in China, there has been a tremendous increase in natural rubber. The supply of natural rubber falls short of demand in recent years. Compared to wheat, rice and other crops, Molecular biology of rubber tree is relatively backward. It will be focusing on how to obtain a large number of genomic information efficiently, screening the gene of shorten the period of breeding, high quality, highyield,strong resistance efficiently and the progress in the functional genomes research.The genomic DNA library is the basic tool for the genome research. It is important for the genome physical mapping, genome sequencing and map-based gene cloning. The rubber tree possesses a complex genome structure,repetitive sequence content of up to 52%. A conventional genomic library construction method (such as shotgun) will increase the sequencing costs and increase the error rate and reduce the splicing efficiency of selected genes. As with tissue specificity and temporal and spatial gene expression of the need to build more than c DNA library to cover the whole genome information.In order to enrich gene encoding region of Hevea brasiliensis, the methylation filtration library was constructed by using E.coli McrBC restriction-modification system. After sequencing and bioinformatics analyses,the following main results are obtained:The titers of the non-amplified library and the amplified library were 2.6×106pfu/ml and 9.0×109 respectively.22 randomly selected clones were identified colony PCR. The length of DNA sequence ranged from 1 kb to 2.5kb,and the rate of positive clones was 86.4%. The library needs for large-scale sequencing.It is a rubber tree to carry out functional genomics studies of valuable resources.This experiment randomly selected from the library of white clones were sequenced, to remove low quality sequences,4819 sequences were obtained effectively. Splicing of these sequences to obtain 913 contigs and 1748 singlets, total of 2661 unique genes (Unigene), of which the longest sequence length of stitching 17954bp.The count showed that GC base pair sequence derived from the average content of 35.86%, lower than the AT base content(64.14%).The 2661 unigenes were blasted against the non-redundant nucleotide and protein and EST database of NCBI.The results showed that 54.31% sequence of NCBI public database of biological functions such as gene sequences and EST sequences highly homologous gene coding sequence, repeat sequences reduced to 7.4%, plastid DNA accounted for 6.05%, unknown new sequence, accounting for 32.10%. It showed that the library contains a lot of energy metabolism, protein synthesis and degradation, transcription and signal transduction, disease resistance and defense related genes by Gene function annotation. Construction of a methylation filtration library in Hevea brasiliensis has been approved feasible.