A and b allotypy in Oryctolagus and Lepus species.

It had been previously shown by the description in wild rabbits Oryctolagus cuniculus of unknown allotypic specificities belonging to the a series and the b series, that the genetic polymorphism found in domestic rabbits was only a part of the genetic polymorphism of the species O. cuniculus. To the known a1, a2 and a3 allotypic specificities have been added in the last years a100 and a101 which are under the control of allelic genes at the a locus. Studies of cross-reactivities in the a system is a way to detect variants of a given allotypic specificity. The phylogenetic studies in the hare Lepus capensis demonstrate that a2 and a3 determinants are allotypic, apparently without polymorphism in this species; indeed, all the tested hares have either a2 or a3 determinants or both. Four presumably "new" allotypic specificities of the b series, A93, A94, A95 and A96 have been found in a population of wild rabbits O. cuniculus from an Island in Tunisia. A95 allotypic specificities against which specific antisera have been prepared, shows cross-reactivities with b4, b5 and b6 allotypes of domestic rabbit. Genetic data demonstrate that A95 is indeed under the control of an allele at the b locus. If schematic mechanisms involving duplication and mutations of genes are suitable to understand the presence of variants and their cross-reactivities, one has to understand how so many genes are involved in allotypy and how it remains stable during evolution.