Genetic linkage and cell distribution analysis of T cell alloantigens in the rat

The T cell alloantigens A.R.T.-1, A.R.T.-2, Pta, Ag-F and RT-Ly-2 were examined for linkage to albinism and the haemoglobin variant Hbb, and for cell expression similarities in the rat. The A.R.T.-1 alloantigen was not linked to either A.R.T.-2, albinism or Hbb. The A.R.T.-2 alloantigen was demonstrated to be closely associated to albinism and Hbb with a recombination frequency of approximately 3% with albinism and 1% with Hbb. The four recombinants (out of 104 animals examined) were subsequently analysed with alloantisera to Ag-F, Pta and RT-Ly-2. These alloantisera detected an antigenic system(s) which appeared to co-segregate with A.R.T.-2 in the recombinants studied Characterization of the specific T cell populations expressing each alloantigen demonstrated that removal of the cells bearing any one of the alloantigens removed all the cells expressing any of the other alloantigens. These results demonstrate that the four alloantigenic systems A.R.T.-2, Pta, Ag-F and RT-Ly-2 are located in the same genetic region of linkage group I, and appear to be expressed on the same peripheral T cell subpopulation(s) in the rat.