Aggression in cataract-bearing α-1,3-galactosyltransferase knockout mice

Abstract

Summary The Galα1-3Galβ1-4GlcNAc epitope is the key antigen in the hyperacute rejection of pig-toman xenotransplantation. In the α-1,3-galactosyltransferase knockout (α-1,3GT-KO) mouse – a model for xenograft donor pigs – a targeted mutation of the α-1,3 galactosyltransferase gene (Ggta1) has been constructed. These mice are depleted of the carbohydrate antigen and besides the mice are also known to develop cortical cataracts. The present study aimed at evaluating the morphology and the degree of the cataract in a population of α-GT KO mice, its age of onset, its progression and the impact the cataract may have on aggression, anxiety and perception of light. The α-gal epitope could be shown in the lenses with lectin GS1 B4 in all wild-type and none of the α-GT KO mice. Histology showed apparent cataract in all α-GT KO mice from six weeks of age. Apart from a single wild-type mouse with a small degree of microscopically visible cataract without epithelial involvement at the age of 30 weeks none of the wild-type mice showed signs of cataract. Behavioural testing demonstrated significantly more mounting behaviour and a longer duration of attacking in the α-GT KO mice. Apart from this, the agonistic behaviour was not influenced by genotype. Neither did the genotype affect anxiety or perception of light.