MULTIPLE, INDEPENDENT RESTRICTION SITE POLYMORPHISMS IN HUMAN DNA DETECTED WITH A CDNA PROBE TO ARGININOSUCCINATE SYNTHETASE (AS)

  • 1 January 1984
    • journal article
    • research article
    • Vol. 36  (4) , 736-749
Abstract
A c[complementary]DNA clone of the human urea cycle enzyme argininosuccinate synthetase (AS) was used to screen for restriction fragment length polymorphisms (RFLP) using a large panel of restriction enzymes. The probe, pAS-1, detects from 15-27 human DNA fragments by Southern gel analysis. In addition to the structural locus on chromosome 9, AS-like sequences are found on at least 10 human chromosomes, including the X and Y. This large number of dispersed pseudogenes accounts for the multiplicity of hybridizing fragments detected with pAS-1. Of 37 restriction enzymes tested, 18 produced excellent digest patterns; of these 18 enzymes, 3 revealed high-frequency, independent RFLP, testing a minimum of 16 individuals with each enzyme. The enzymes producing high-frequency polymorphisms are HindIII (allele frequencies 0.30 and 0.70), HindII (0.13 and 0.87), and BamHI (0.56 and 0.44). Most of the polymorphic alleles are found in Caucasians, American blacks and Orientals. The RFLP detected with HindIII maps to chromosome 9(9q11-q22), although not to the structural locus; the others are autosomal but otherwise unassigned. Two additional 6-base enzymes and a 4-base enzyme, MspI, revealed further individual variation, but these variants were not shown to segregate in families yet. Approximately 0.8% high-frequency RFLPcut site per enzyme or a minimum of 0.05% heterozygosity/nucleotide were observed. pAS-1 should prove useful in assigning high-frequency RFLP to several human chromosomes.