The occurrence of conserved epitopes in the immune system was investig
ated on the leukocytes of cattle, river buffalo, sheep, camel, swine a
nd humans by indirect immunofluorescence and flow cytometry. The distr
ibution of the most conservative epitopes on leukocyte sub-populations
suggests that the expression pattern of the proteins is similar, West
ern blotting experiments indicate that the recognized antigens are str
uctural homologues.