Influence of oncogenicity of Marek' disease virus on evaluation of genetic resistance.
Resistance to Marek's disease ( MD) is, in part, genetically determined and linked to the major histocompatability complex. The genetic resistance of 9 previously characterized lines of chickens and also of the inbred UCD-003 and 4 congenic lines was evaluated by challenge with JM-10. Five lines were highly resistant. These included the N-line and two derivatives from N-line (N-2 and N-5), PDRC strain, and one of the congenic UCD lines. The PDRC genotype is unknown, but the 3 related lines carry the B21 allele and the UCD line carries the BQ allele, which appears to be similar to B21. The UCD-003 and the other 3 congenic lines were moderately resistant while S-strain, P-2 and P-5 lines were highly susceptible to JM-10. The total MD incidence varied from 0 to 100% among the lines. Challenge with highly oncogenic virus isolates like GA-5, and especially the recently isolated RB-1B, caused high incidences of MD in all lines and, thus, did not permit differentiation of genetic resistance levels as was possible with the less oncogenic JM-10.
D000818:Animals; D002645:Chickens / Q000235:genetics / Q000276:immunology; D003433:Crosses, Genetic / Q000662:veterinary; D008381:Herpesvirus 2, Gallid / Q000276:immunology / Q000472:pathogenicity*; D008380:Marek Disease / Q000235:genetics* / Q000276:immunology