U.S. Department of Agriculture: Agricultural Research Service, Lincoln, Nebraska
Date of this Version
2009
Abstract
The recessive genetic defect of osteopetrosis (marble bone disease) in Red Angus cattle has been defined by a mutation in the bovine SLC4A2 gene located on Bos Taurus chromosome 4. The mutation was discovered in a joint effort by the Red Angus Association of America (RAAA), University of Illinois, University of Nebraska-Lincoln, University of Wyoming, and the Agricultural Research Service of the United States Department of Agriculture (USDA-ARS). The information is available for public use without restriction, taking into account the disclaimers and caveats described below.
The causative mutation is a deletion of ~2721 bp of the SLC4A2 gene. This deletion encompasses the entirety of exon 2 and the 5’ portion of exon 3. A diagnostic assay that has been used for screening several hundred Red Angus animals is based on the amplification of a normal amplicon and a deletion-only amplicon using a trio of PCR primers (see below). Screening for other sequence variation along this portion of the gene among cattle populations has not been completed, so the potential for alleles that do not produce amplification products due to SNP under the primers exists. This likelihood is reduced for the allele containing the deletion (i.e. lower chance of false negatives) since they share a common haplotype, but the precise likelihood of false negative is not known at present. Conversely, the probability of SNP under the primers in SLC4A2 alleles with normal function is higher, such that the appearance of apparently homozygous mutant but unaffected animals is not negligible due to failure of the normal functioning allele to amplify. However, we have not observed any of this class in the approximately 1000 animals in the test populations.
Comments
Published by Tim Smith (2009) at http://www.ars.usda.gov/sp2UserFiles/Place/54380510/Publications/RedAngusOsteopetrosisSequenceInformation.pdf