CHROMOSOMAL ASSIGNMENT OF 311 SEQUENCES TRANSCRIBED IN HUMAN ADULT TESTIS

A total of 311 expressed sequence tags (ESTs) derived from human adult testis have been assigned to human chromosomes by Southern analysis o f a monochromosome somatic cell hybrid panel. Over 70% of the ESTs sho w conservation to hamster and mouse DNA, and the overall distribution of transcripts correlates well with physical chromosome size and to a greater extent with male meiotic chromosome length. The notable except ion is the X chromosome, for which the number of testis-derived ESTs i s greatly underrepresented. This finding may reflect inactivation of t he X chromosome during the meiotic phase of spermatogenesis and a cons equent selection against large numbers of X-linked germ cell transcrip ts. Further analysis of the distribution of testis ESTs showed that th e EST density remains significantly correlated with the recombination density of each autosome. Analysis of a comparable number (320) of bra in EST autosome assignments showed no similar correlation. These data suggest a specific association between transcription in testis tissue and male meiotic recombination. (C) 1997 Academic Press.