Population genetics of Aa and Ab immunoglobulin allotypes in wild rabbits of south-eastern Australia. I. Allotype frequencies.

Aa and Ab allotype frequencies have been investigated in wild rabbit populations throughout Victoria and South-east South Australia. The overall mean allele frequencies for thirty-three populations are 0-53:0-12:0-36 for a1:a2:a3 and 0-72:0-22:0-05 for b4:b5:b9. The b6 allele was not found anywhere. The a1 frequency has been found to increase in proportion to increases in mean annual rainfall. While considerable variations exist in allotype and allele frequencies from area to area, the relationships a1 greater than a3 greater than a2 and b4 greater than b5 greater than b9 are almost always observed. The results are discussed in terms of the historical origins of Australian wild rabbits and possible genetic mechanisms to explain the maintenance of allotype 'hierarchies' in large populations breeding at random.