| This research were taking cotton and its reference genome grape,cocoa,Arabidopsis and poplar to do comparitive genomic analysis,in this reasearch,the chromosomes evolution of cotton,the evolution of cotton fiber development related genes and the separation time of cotton during evolution process were measured.Research have shown that because of the whole genome duplication event,the evolution of the cotton genome were asymmetry,with a large number of gene loss,chromosome rearrangement.In diploid cotton,70% of the gene were lost,In tetraploid cotton,50% of the genes were lost,the size of this loss was quite highly,and the loss process was randomly and consistented with the exponential distribution process.The study found that during the process of two diploid cotton formed heterotetraploid cotton,the evolution of cotton genome were unbalanced.Studies also calculate the separation time of the species,which found that the separation time of cotton and cacao was 38 mya ago.The separation time of cotton A and cotton D was 4 mya ago,while in heterotetraploid,the subgenomic group D evolution rate was higher than that of sub genome A,which means unbalanced evolutionary rate.The study also obtained a list of homologous collinearity ratios of cotton,cocoa,grape,Arabidopsis thaliana and poplar.The cotton fiber development-related genes were found in cotton A genome,cotton D genome,cotton AD genome,grape,cocoa,Arabidopsis thaliana,each number was 192,204,658,84,112,128 and 176,which may be derived from the common ancestor of dicotyledonous plants.The evolution of cotton fiber development-related genes was also unbalanced,and this unbalanced phenomenon was more pronounced in the process of two diploid cotton A and D forming heterologous tetraploid cotton AD.The genome of cotton and its outer group was compared by multidisciplinary method,and the comparative genomics database of cotton was improved.The related results were of great significance to the study of cotton genomics. |
PDF Full Text Request