Irradiation-reduced human chromosome 21 hybrids.
Rodent-human somatic cell hybrids have been constructed which contain fragments of human chromosome 21 as their only human material. This was done by irradiating rodent-human somatic cell hybrids containing a complete chromosome 21 to fragment the genome and then rescuing human GAR synthetase and various amounts of flanking chromosome 21 DNA by fusing with GAR synthetase-deficient hamster cells and selecting for growth in purine-free medium. Four irradiation-reduction hybrids were produced by this method and contain the distal, proximal, and central portions of the long arm of human chromosome 21, all centered about GAR synthetase. These irradiation-reduction hybrids were used as a panel to regionally map single-copy and individual copies of repetitive sequences. Using these hybrids along with another independently constructed hybrid, the GAR synthetase gene was mapped distal to SOD-1 and proximal to CP21G1(D21S60). Of special interest is the regional mapping of the gene for the amyloid beta-protein distal to pPW236B(D21S11) and proximal to SOD-1.
Graw
S
S
Massachusetts Institute of Technology, Cambridge 02139.
Davidson
J
J
Gusella
J
J
Watkins
P
P
Tanzi
R
R
Neve
R
R
Patterson
D
D
D000818:Animals; D019731:Carbon-Nitrogen Ligases; D002874:Chromosome Mapping; D002891:Chromosomes, Human, Pair 21; D006224:Cricetinae; D003412:Cricetulus; D004247:DNA / Q000235:genetics; D005819:Genetic Markers; D006801:Humans; D006822:Hybrid Cells / Q000528:radiation effects*; D008025:Ligases / Q000235:genetics; D009693:Nucleic Acid Hybridization
D005819:Genetic Markers; D004247:DNA; D008025:Ligases; D019731:Carbon-Nitrogen Ligases; C022387:phosphoribosylamine-glycine ligase