Abstract

Quantitative two-dimensional polyacrylamide gel electrophoresis has been used to search for variation among liver proteins in flocks of sheep which had been selected for either resistance or susceptibility to sporidesmin- induced liver damage. The goal was identification of proteins whose DNA sequences might be used to select animals for resistance to facial eczema. The quantitative gel techniques were used because of their ability to detect variability among many proteins in a single tissue sample. Differences in relative proportion were tested for 62 proteins among 5 ewes from each of the resistant and susceptible flocks. There were 7 proteins which showed statistically significant differences (P<0.05) between the flocks. When an analysis was made of changes in the relative proportions of proteins 2 days after experimental challenge of resistant flock ewes (n=8) with sporidesmin, 0.13 mg per kg body weight, 25 of 79 liver proteins showed significant change (P<0.05). This included partial loss of a 25 kDa, pI 5.7, protein which was also three times more abundant in undosed susceptible than undosed resistant females. These results are discussed in terms of the possible relationships between protein variation and the magnitude of toxic tissue damage.

CJ, Morrow, GW Asher, JF Smith, and FA Veldhuizen

Proceedings of the New Zealand Society of Animal Production, Volume 53, , 417-422, 1993