Chinese Scientists Complete the Precise Sequencing of Chromosome 4 of Rice Genome (CAS)

The sequencing of Chromosome No. 1 and 4 of rice genome has reached the finishing line. __The British Magazine Nature of November 21, 2002 issue made a front-paged report on the accomplishment of Chinese and Japanese scientists to complete the sequencing of Chromosome No. 1 and 4 of rice genome in detail. Nature editors regard the two papers as milestone within the International Rice Genome Project since the completion of rice genome draft.

This is so far the largest sequencing work undertaken and fulfilled by Chinese scientists, symbolizing the strong capability of China's genome complete draft sequencing. China has become one of the genomics power countries.

Dr. Bin HAN the leader of Sequencing Experts Group, researcher at the National Genome Research Center, CAS, noted, they concluded the precise sequencing of the full length Chromosome 4 of the Oryza sativa Rice Genome through cloning, all together 35 million base pairs, with a precision rate of 99.99% and covering 98% of the full length sequence of the chromosome (only leaving seven small gaps). This achievement has reached the international standard for the complete draft sequencing of genome.

In addition, Chinese scientists have also done structural and functional analysis on the Chromosome 4 of the Rice Genome. 4,658 genes have been identified at their precise locations on the Chromosome, paving a way for the further work on identifying their functions. They also finished the full length sequencing of the centromere of Chromosome 4, so marked the first time of sequencing the centromere of the chromosome of advanced life, provided necessary structural basis for the investigation on the functions of centromere, the stability and replication of chromosomes, and also laid a base for the development of transferable "artificial rice or plant chromosomes". They have found out the distribution rules and inter-gene location relationships of some replicate sequences, identified the distribution of gene clusters on Chromosome 4 and predicted the potential interrelationship between genes.-1