IDENTIFICATION OF 4370 EXPRESSED SEQUENCE TAGS FROM A 3'-END-SPECIFICCDNA LIBRARY OF HUMAN SKELETAL-MUSCLE BY DNA-SEQUENCING AND FILTER HYBRIDIZATION

A systematic study on the mRNA species expressed in the human skeletal muscle is presented in this paper. To carry on this study, a new meth od has been developed for the construction of unbiased cDNA libraries specially designed for the production of ESTs corresponding to the 3'- end portion of the mRNAs. The method has been applied to human skeleta l muscle, where the analysis of the transcription profile is particula rly difficult for the presence of several very abundant transcripts. T o detect and quantify high-level mRNAs, the first 1054 ESTs were obtai ned from randomly selected clones. The 10 most abundant transcripts ac counted For >45% of the clones. Subsequently, these transcripts were i dentified by Filter hybridization, thus making DNA sequencing more pro ductive. Overall, 4370 clones were identified: 3372 by DNA sequencing and 998 by filter hybridization. The number of groups of sequences ide ntifying individual transcripts was relatively low compared with other tissues, resulting in a total of 934 groups out of 4370 ESTs. Of thes e, 719 groups were represented by only one sequence.