DETERMINATION OF THE CHROMOSOMAL LOCATION OF A GLUTAMATE OXALOACETATE TRANSAMINASE STRUCTURAL GENE USING TRITICUM-AGROPYRON TRANSLOCATIONS

Gary E. Hart 1, David E. McMillin 1, and E. R. Sears 2

1 Genetics Section, Department of Plant Sciences, Texas A&M University, College Station, Texas 77843
2 Department of Agronomy, University of Missouri, Columbia, Missouri 65201

The glutamate oxaloacetate transaminase (GOT) zymogram phenotypes of a series of 15 translocation lines, a chromosome addition line and a chromosome substitution line were determined. In each of the translocation lines a segment of the long arm of Triticum aestivum chromosome 3D has been replaced by a portion of an Agropyron elongatum homoeologue. Evidence was obtained that the products of the T. aestivum GOT-3 triplicate structural gene set randomly dimerize with the product of the homoeologous A. elongatum gene. Each translocation chromosome was found to carry either Got-D3 or Got-Ag3. By correlating the zymogram phenotype expressed by each translocation line with the observed frequency of meiotic pairing of each 3D/3Ag translocation chromosome with telocentric-3DL, it was shown that Got-D3 is located in the proximal portion of 3DL, slightly more than 4.3 crossover units from the centromere. The results of this genetic study confirm and extend earlier conclusions derived from cytogenetic studies as to the physical nature of the various 3D/3Ag chromosomes.

Submitted on October 29, 1975