Variations in the CCR5-gene and its effect on CAE, in goat

Abstract: Caprine Arthritis Encephalitis (CAE) is a disease negatively affecting goats, around the world. A mutation on the CCR5-gene has showed an increase in viral load. CAE is a lentivirus that affects the monocytes/macrophages. It is a disease similar to HIV in humans and the animal can be a carrier for months to years before symptoms start to show. The symptoms can be severe, arthritis being the most common for adult goats. This study aimed to find variations in the CCR5-gene that can affect the onset of disease, and to complement earlier studies. It also includes more different breeds, than previously studied. It was also to study the possibility of breeding as a control measure, for the disease. Blood samples and nose swabs from 127 goats were sequenced and analyzed. Four Swedish breeds were included; Swedish lantras, Göingegoat, Lappgoat and Jämtgoat. Two mutations were found, one that has previously been shown to possibly have an impact on pro-viral load. There were variations found, in the genotypes, between and within some of the breeds, especially for the breeds Jämtgoat and Göingegoat. There were differences found in genotype- and allele frequencies for the different breeds. This is the second only study on this subject, on Swedish goat breeds. No significant differences could be found in the correlation between genotype and prevalence of CAE, in the Swedish breeds, though the sample size of sero-positive animals was small. The genotype- and allele frequencies varied significantly between the breeds, making the possibility for breeding different, for each. Nothing conclusive could be said, in this study, about the possibility of breeding to contain CAE, but the frequencies could be a basis for further studies into the subject. More studies, with more sero-positive animals and increased sample size, need to be conducted.