Pgm Locus Research Articles

The distribution of red cell enzyme and serum protein groups in a population of Dani (Pit River, West Irian).

Blood samples from a series of Dani speaking persons from Pit River, West Irian have been studied for genetic variants in 14 red cell enzyme and 5 serum protein systems. Four of the red cell enzyme systems were polymorphic: acid phosphatase, 6 phosphogluconate dehydrogenase, adenosine deaminase and phosphoglucomutase (locus 1). Two of the serum protein systems, haptoglobin and transferrin, were polymorphic. In the other systems three MDH “New Guinea-1” variants were detected and two persons with variants, one MS and one SS, in the protease inhibitor system were detected also. An unusual variant in the PGM (locus 2) system has not yet been adequately identified. All other systems were monomorphic.

Isolation and characterization of HL-A variants in cultured human lymphoid cells.

We have developed a procedure for immune selection in an established human lymphoid cell line based on HL-A, the major human histocompatibility locus. After a single brief exposure to selective conditions, HL-A2 variant clones were isolated from an HL-A2/HL-A3 heterozygous line. The variant clones occurred at a frequency of about 1 x 10(-6). The variant phenotype was stable during prolonged growth in the absence of antiserum after isolation. The variant sublines bound [unk] 1/1000 the HL-A2 antibody per cell as the parent line. Variation was specific in that expression of antigens not selected against was unimpaired. Loss of the chromosome bearing HL-A2 was excluded as the cause of variation because the variants, like the parent line, were heterozygous for phosphoglucomutase (EC 2.7.5.1) determined by structural locus PGM(3), which is linked to HL-A.

Gene loss in human teratomas.

If benign cystic teratomas (dermoid cysts) of the ovary arise from a germ cell that has undergone meiosis, they should be missing genes which are present in the person. Three independently segregating allelic isozymes in 11 benign cystic teratomas of the human female ovary were compared with normal tissue of the same case. Dermoid cysts from persons heterozygous for these isozymes are frequently homozygous for that particular gene product. One of two dermoid cysts is homozygous for glucose-6-phosphate dehydrogenase, two of four tumors are homozygous for phosphoglucomutase at the PGM(1) locus, and two (or more) of eight tumors are homozygous for phosphoglucomutase at the PGM(3) locus in women heterozygous for these allelic isozymes. These findings are consistent with the hypothesis that these tumors arise from a germ cell which has undergone meiosis with varying degrees of crossing-over.