ISOLATION AND LOCALIZATION OF TRANSCRIBED SEQUENCES ON HUMAN-CHROMOSOME-22

Recently, we reported the generation of a heteronuclear (hn) cDNA libr ary from a human x rodent somatic cell hybrid retaining human chromoso me 22. Here, we report the characterization and localization of 12 cDN A derived clones from this library. Human-specific cDNA sequences have been selectively amplified by inter-Alu PCR. To exclude Alu transcrip ts, only clones with inserts larger than 500 bp were analyzed. Ten of the 12 clones were localized by PCR on chromosome 22, with four clones mapping on additional chromosomes. One PCR-localized clone and two ad ditional clones were mapped on chromosome 22 by in situ hybridization. Transcripts in human cells were identified for seven of the eight clo nes analyzed by RT-PCR. None of the clones showed significant sequence similarities within the GenBank and EMBL databases, indicating that t hese clones represent previously unknown genes. This is the first repo rt on the isolation of chromosome 22-specific transcripts from a human x rodent somatic cell hybrid.