H-2 antigen frequencies among wild mice from Chile.

Thirty-five wild mice (Mus musculus L.) were captured at four different localities in Chile. The mice were typed for the presence of 15 K-, 11 D-, 14 A-, and two E-region H-2 antigens, using the complement-antibody microcytotoxicity assay. The mice from the sample representing the largest locality had a characteristic antigenic profile distinguishing them from other mouse populations thus far studied. With respect to class I H-2 antigens, the profile was characterized by the presence of antigens H-2K.16, 31, 103, 19, 108, 21, 33, 26, 115, and H-2D.4, 106, 30, 32, 111, 114, and 18 (in order of decreasing antigen frequency), and by the absence of antigens H-2K.15, 17, 20, 113, 116 and H-2D.2, 9, 110, and 112. The profile was, furthermore, characterized by the relatively high frequency of antigens H-2K.16, 31, and H-2D.4 and 106. The profile of class II antigens was also unique to the Chilean population but less conspicuously so than that of the class I antigens. Analysis of antigenic associations suggested that among the 34% blank H-2K alleles there were at least two coding for relatively frequent but as yet unidentified K antigens. Similarly, among the 57% blanks at the H-2D locus there were at least two frequent alleles encoding unidentified D antigens. Analysis of genetic distances suggested similarity between South American mice and mice from coastal regions of Europe.