Submitted to: Plant and Animal Genome Conference Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 30, 2002
Publication Date: January 11, 2003
Citation: CLAWSON, M.L., HEATON, M.P., LAEGREID, W.W. BETA2-MICROGLOBULIN HAPLOTYPE STRUCTURE IN U.S. BEEF CATTLE AND CORRELATION WITH SERUM IGG CONCENTRATION IN NEWBORN CALVES. PLANT AND ANIMAL GENOME CONFERENCE PROCEEDINGS. 2003. Abstract No. P261. Technical Abstract: Calves are born without circulating immunoglobulin and must receive maternal immunoglobulin via colostrum to obtain passive immunity. Failure of immunoglobulin passive transfer (FPT) increases neonatal mortality and is a significant source of economic loss in both U.S. beef and dairy cattle. The Fc receptor of neonates (FcRN) has been shown in various animal models to regulate Ig concentration in the colostrum of the mother and also across the intestinal lumen of the neonate. A similar role for FcRN has been proposed in cattle. Functional FcRN is a heterodimer of the MHC Class I alpha-chain homolog FCGRT and Beta2-microglobulin (Beta2m). In U.S. beef cattle, two haplotypes of FCGRT; one in dams and one in calves have been correlated with low calf serum IgG concentrations in a case-control study design (Laegreid et al., Mammalian Genome, In press). To evaluate whether variation in the Beta2m locus also correlates with FTP phenotypes, we sequenced two regions of the Beta2m locus in a multibreed panel of 96 beef cattle. Twelve single nucleotide polymorphisms (SNPs) were identified and verified by genotyping assays using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS). Proper segregation of each SNP was observed in a reference population. At least eight unambigous Beta2m haplotypes have been identified and their frequencies estimated in U.S. beef cattle. Here we present preliminary results correlating Beta2m haplotypes with serum IgG concentration in neonatal calves in a case-control study.