Effect of age and MHC-genotypes on Rous Sarcoma Virus induced tumor profile index and mean survival time

Present study was undertaken to determine the effect of age on Byran Standard strain of Rous sarcoma virus (Rous associated virus-A) [BS RSV (RAV-1)] or (RSV-A) induced tumorigenesis and growth pattern of primary wing-web tumors in Synthetic dam line (SDL) chicks. Five different age-groups (3, 7, 14, 21 and 35-days-old) of SDL chicks were infected with RSV-A @ 2000 pock forming units (pk.f.u.)/0.2 ml, s.c., in the left wing-web. Primary wing-web tumors were induced between 3–10 days post-inoculation (DPI) in different age groups. Effect of age on tumor progression or regression was analyzed through ANOVA using software SPSS version 16.0 and mean tumor profile index (TPI) was calculated. Results revealed that mean TPI scores among different age-groups ranged from 3.50±0.223 to 5.00±0.29, which was non-significant. Despite nil significant difference among different age-groups, 3-days-old chicks exhibited highest TPI (5.00±0.219) and rapid tumor progression with least mean survival time (MST). Results further demonstrated variation in tumor growth pattern in resistant and susceptible chickens (based on major histocompatibility complex (MHC) genotypes) under different TPI scores.