The Construction Of Chinese Fir CpG Library And The Whole Genome DNA Methylation Detecion

There is an obvious heterosis in the intraspecific hybridization of Chinese fir, but the molecular mechanism of heterosis in F1 combination is not clear. Studies showed that the DNA methylation the learned as the epigenetic invovled in heterosis.DNA methylation,especially methylation of cytosine(5mC) in eukar-yotic organism, has received considerable attention in recent years,and its plays an essential role in regulating plant development.Approximately 60-90% of all CpG sequneces in the genome are methylated,while un-methylated CpG dinucleotides are mainly clustered in the CpG rich sequence,termed CpG island,of the gene promoter region. CpG island also named HTF(Hpa II tiny fragment) island, Active gene sequences of CpG island make a role in resistance methylation, whereas the GC sequence of inactive genes usually produce methylation to inhibit the gene expression. Thus, the search for CpG islands can provide important clues for the discovery of genes.The main result are as follows:1. Constructing CpG library use the suppression subtractive hybridization:generally, suppression subtractive hybridization be used to build cDNA library,the study,the first time use the technique to build the Chinese fir DNA CpG library,and the results show that the technique si feasible.2. Detection of global DNA methylation of Chinese fir:deceting the lever methylation of the parents and hybrid progeny(the dominant species and the disadvantages kind) by High Liquid Chromatography,in order to compare that whether there are any difference and correlation between the offspring of the dominant species and the disadvantages kind, while comparing with MSAP. The results show that there are synchronization of the level of Chinese fir heterosis studied by High Liquid Chromatography and Methylation-senstive amplified polymorphism,and the overall level of methylation of parental species and disadvantages are higher than the dominant species in Chinese fir,of course we also find that there are negative correlation between heterosis and the level of genomic methylation of Chinese fir...