Chromosomal localization of human aspartate aminotransferase genes by in situ hybridization.

The localization of the human genes for cytosolic and mitochondrial aspartate aminotransferase (AspAT) has been determined by chromosomal in situ hybridization with specific human cDNA probes previously characterized in our laboratory. The cytosolic AspAT gene is localized on chromosome 10 at the interface of bands q241-q251. Mitochondrial AspAT is characterized by a multigene family located on chromosomes 12 (p131-p132), 16 (q21), and 1 (p32-p33 and q25-q31). Genomic DNA from ten blood donors was digested by ten restriction enzymes, and Southern blots were hybridized with the two specific probes. Restriction fragment length polymorphism was revealed in only one case for cytosolic AspAT, with PvuII, while no polymorphism for mitochondrial AspAT was found.