Abstract：Abstract：To investigate the gene expression and to separate clones which are important genes related to fiber development,a cDNA library of Ramie（Boehmeria nivea(L.)Gaud）bark was constructed. Some quality analysis,such as the titer and insert cDNA length of cDNA library,indicated that the library was eligible.The sequencing of cDNA clones and the analysis of expressed sequence tags(EST) were reported,274 valid ESTs were generated from 384 cDNA clones.Result showed that EST sequences assembled out 217 TUTs and endued 20.8% redundancy. 91 ESTs with known or putative function and 126 novel ESTs were identified by Blast searches against the NCBI non-redundant databases.These ESTs were classified into 9 different categories,the cell wall related ESTs were 5.5%.The expression levels in different development, different tissues of different genotype was detected by semi-quantitativeRT-PCR with 18S rRNA as internal control. The results indicated the expression of ADF and Tubulin beta genes could be found in these tissues,.The hightest expression level were appeared in bark of cover-line stage. The expression level of ADF and Tubulin beta genes is particular to tissues and development stages.
