THE HUMAN TENASCIN GENE

The human tenascin-R gene encodes a multidomain protein belonging to t he tenascin family, until now detected only in the central nervous sys tem, During embryo development, tenascin-R is presumed to play a pivot al role in axonal path finding through its adhesive and repulsive prop erties, Recently, the primary structure of human tenascin-R has been e lucidated (Carnemolla, B., Leprini, A., Borsi, L., Querze, G., Urbini, S., and Zardi, L. (1996) J. Biol. Chem. 271, 8157-8160). As a further step to investigate the role of human tenascin-R we defined the struc ture of its gene, The gene, which spans a region of chromosome 1 appro ximately 85 kilobases in length, consists of 21 exons, ranging in size from 90 to >670 base pairs, The sequence analysis of intron splice do nor and acceptor sites revealed that the position of introns in human tenascin-R are precisely conserved in the other two tenascin family me mbers, tenascin-C and tenascin-X, The determination of intronic sequen ces flanking the exon boundaries will allow investigation of whether m utations may be responsible for altered function of the gene product(s ) leading to central nervous system development defects.