DNA profiling reveals remarkably low genetic variability in a herd of SLA homozygous pigs

Inbred strains of rodents have become indispensable for a wide range of bio logical studies. It has generally been accepted that genetic uniformity is unlikely to be achieved before 20 generations of brother x sister matings d iscouraging attempts to inbreed larger mammals. Nevertheless, pigs, homozyg ous for the swine MHC haplotype SLA b/b, have been inbred at the Babraham I nstitute for almost thirty years and used for immunological studies. Since the herd had not been studied at the DNA level, DNA profiling at multiple h ypervariable loci was performed and surprisingly little genetic polymorphis m and extremely high inter-individual resemblance were observed reminiscent of that observed in inbred strains of mice. (C) 1999 Harcourt Publishers L imited.