ASSIGNMENT OF THE HUMAN FOLATE TRANSPORTER GENE TO CHROMOSOME 21Q22.3BY SOMATIC-CELL HYBRID ANALYSIS AND IN-SITU HYBRIDIZATION

We have used the human folate transporter cDNA and a human genomic clo ne hybridizing to the cDNA to perform chromosomal mapping of the folat e transporter gene. Human-rodent somatic cell hybrid analysis using th e cDNA as the probe revealed perfect segregation with human chromosome 21. In situ hybridization of the cDNA probe to human metaphase chromo some spreads mapped the folate transporter gene to the distal long arm of chromosome 21, band q22.3. This chromosomal location was confirmed by fluorescence in sine hybridization using the genomic clone. (C) 19 95 Academic Press, Inc.