IBS   24490
INSTITUTO DE BIOLOGIA SUBTROPICAL
Unidad Ejecutora - UE
artículos
Título:
BoLA-DRB3 gene polymorphisms influence Bovine Leukaemia Virus infection levels in Holstein and Holstein x Jersey crossbreed dairy cattle
Autor/es:
H. A. CARIGNANO; A.AMADIO; I. ALVAREZ; M. POLI; M. E. CAFFARO; M. J. BERIBE; G. GUTIERREZ; J. NANI; M. MIRETTI; K. TRONO
Revista:
ANIMAL GENETICS
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Lugar: Londres; Año: 2017 vol. 48 p. 420 - 430
ISSN:
0268-9146
Resumen:
Bovine Leukemia Virus (BLV) infections, causing persistent lymphocytosis and lethal lymphosarcoma in cattle, have reached high endemicity in dairy farms. We observed extensive inter-individual variation in the level of infection (LI) by assessing differences in proviral load (PVL) in peripheral blood. This phenotypic variation appears to be determined by host genetics variants, especially those located in BoLA-DRB3 MHCII molecule. We performed an association study using sequencing-based typed DRB3 alleles over 800 Holstein and Holstein x Jersey cows considering the LI in vivo and accounting for filial relationships. The DBR3*0902 allele was associated with a low level of infection (LLI) (< 1% of circulating infected B-cell) while DRB3*1001 and DRB3*1201 alleles were related to a high level of infection (HLI). We found evidence that 13 polymorphic positions located in the pockets of the peptide-binding cleft (PBC) of the DRB3 alleles were associated with LI. DRB3*0902 had unique haplotypes for each of the pockets: Ser13-Glu70-Arg71-Glu74 (Pocket 4) Ser11-Ser30 (Pocket 6), Glu28-Trp61-Arg71 (Pocket 7) and Asn37-Asp57 (Pocket 9) and all of them were significantly associated with a LLI. Conversely, Lys13-Arg70-Ala71-Ala74 and Ser13-Arg70-Ala71-Ala74 corresponding to the DRB3*1001 and *1201 alleles, respectively, were associated with a HLI. We showed that the amino acids specific pattern in the DRB3*0902 PBC might be related to the set-point of a very low PVL level in adult cows. Moreover, we identified two BoLA-DRB3 alleles associated with a HLI, which is compatible with a highly contagious profile.