Association of BLV-infection profiles with alleles of BoLA DRB3.2 gene

JULIARENA MARCELA; POLI MARIO; SALA LIVIO; CERIANI CAROLINA; GUTIERREZ SILVINA; DOLCINI GUILLERMINA; RODRIGUEZ EDGARDO; MARIÑO BETINA; RODRIGUEZ DUBRA CAIN; ESTEBAN EDUARDO

ANIMAL GENETICS

Blackwell Publishing

Año: 2008 vol. 39 p. 432 - 438

0268-9146

The bovine leukemia virus (BLV) causes lymphosarcoma and persistent lymphocytosis (PL). Some Class II MHC gene polymorphisms have been associated with resistance and susceptibility to development of lymphosarcoma, PL or reduced numbers of circulating BLV-infected lymphocytes. BLV- infected Holstein cattle can be diferentiated into two profiles according to their proviral load and humoral response to major BLV structural proteins. The influence of the polymorphism of BoLA DRB*3.2 gene on described BLV-infection profiles was examined. The genotyping of 230 Holstein cattle from the Argentinean breed previously characterized as low proviral load (LPL) and high proviral load (HPL) infection profiles, was carried out by PCR-RFLP and PCR-SSO. The association between BoLA DRB*3.2 alleles and BLV-infection profile was determined as the odds ratio (OR). Chi square test was done to determine if OR was statistically significant. By the PCR-SSO 2 subtypes of the allele *11 were found (ISAG*0901 and *0902). Allele ISAG *0902 showed a stronger association to LPL profile (OR = 8.24; p < 0.0001) than allele *11 itself (OR = 5.82; p < 0.0001). Allele ISAG *1701 (*12) also showed significant association to LPL profile (OR = 3.46; p < 0.0055). Only one allele, ISAG *1501 or 03 (*16) showed significant association to HPL (OR = 0.36; p < 0.0005). DRB*3.2 alleles were assigned to 3 categories: Resistant (R), Susceptible (S) and Neutral (N). Based on their DRB3 genotyping, cattle were classified as N/N, N/R, N/S, R/R, R/S or S/S. Although our data suggests that besides BoLA DRB*3.2 alleles other genetic or epigenetic factors may influence BLV-infection profile, up to this date allele ISAG *0902 appears as the best allele associated with BLV resistance in Holstein cattle