THE PRELIMINARY TRANSCRIPT MAP OF A HUMAN SKELETAL-MUSCLE

By sequencing 11405 individual expressed sequence tags (ESTs) from a c DNA library of a human skeletal muscle, we identified 1945 individual transcripts, 725 of which showed no correspondence with known human ge nes, We report here the chromosomal localization of 267 of these, obta ined by radiation hybrid (RH) mapping, The map position of additional 242 ESTs from the same library, corresponding to known human genes, is also reported, The resulting information provides a preliminary genom ic transcriptional profile of a human muscle, Several genes occur in c lusters on different chromosomes, Moreover, chromosomes 17, 19, 21 and X appear to be significantly rich in muscle ESTs, By analysing severa l collections of ESTs from different tissues, we observed significant deviations in the distribution of ESTs by chromosome in fetal heart, a dult brain and adult retina, supporting the hypothesis that a non-rand om localization of genes expressed in specific tissues might not be un common, The selective concentration of expressed genes in some chromos omes and in specific chromosomal subregions in a given tissue might re flect the existence of batteries of genes under the same control mecha nisms, regulating tissue-specific gene expression.