Genomic structure of a copy of the human TPTE gene which encompasses 87 khon the short arm of chromosome 21

The testis-expressed human TPTE is a putative transmembrane tyrosine phosph atase, probably involved in signal transduction pathways of the endocrine a nd/or the spermatogenetic function of the testis. TPTE was mapped to the pe ricentromeric region of human chromosomes 21 and 13, and to chromosomes 15, 22, and Y. It is unknown which of the TPTE copies are transcribed, contain intronic sequences, and/or have open reading frames. Here, in silico analy sis of the genomic sequence of human chromosome 21 allowed the determinatio n of the genomic structure of a copy of the TPTE gene. This copy consists o f 24 exons and spans approximately 87 kb. The mapping position of this copy of TPTE on the short arm of chromosome 21 was confirmed by FISH using the BAC 15L0C0 clone as a probe that contains almost the entire TPTE gene. This is the first description of the genomic sequence of a non-RNR gene on the short arm of human acrocentric chromosomes.