Close linkage between the C blood group locus and the locus controlling amino acid transport in sheep erythrocytes

Abstract

Data from 838 Finnish Landrace or Finnish Landrace crossbred sheep showed a highly significant correlation between phenotypes of the C blood group system and erythrocyte amino acid transport variants. Erythrocytes with normal amino acid transport properties (GSH high, Ly-type) were Cb-positive or Cb-negative.Erythrocytes with the amino acid transport lesion (GSH low, Ly + ) were never Cb-negative. Sheep erythrocytes homozygous for Cb showed stronger lysis reactions with anti-Cb than heterozygous cells. Lv + sheep were nearly always homozygous for C*, whereas most Ly-sheep were heterozygous or Cb-negative. Inheritance studies provided strong evidence that this association is due to close genetic linkage. Glutathione concentrationsThese were determined on whole blood samples using DTNB (5,5'-dithiobis-2nitrobenzoic acid) as chromogen (Beutler, Duron & Kelly, 1963). Erythrocytes with less than 50 mg GSWlOO ml were classified as low GSH type and those with concentrations above 60 mg/100 ml were classified as high GSH type (Tucker & Kilgour, 1970). ResultsErythrocytes from 838 sheep comprising 5 different flocks were tested with blood grouping reagents in the R, A, B, C and M systems. They were also tested for 120