Vol. 12, Issue 5 (2023)

Author(s):
Laltlankimi Varte, Dipak Deka, Kuldip Gupta and Amarjit Singh

Abstract:
The present study was carried out with the objective to detect and analyse one the important viral oncogenes (vIL8) sequences of field Marek’s Disease Viruses. Despite vaccination, field isolates of MDV-1 tends to increase in virulence, developing symptoms of MD with obvious visceral lymphoma making Marek’s Disease an economically important viral disease of chickens. vIL8 gene being one of the important oncogenic genes of MDV-1 was amplified and sequenced. Homology comparison of the nucleotide sequences 5 isolates and other reference was found to be 99.1 – 100%. High nucleotides and amino acids identities between isolated MDVs and the reference MDVs were observed, indicating the genetic stability of this gene. The present study indicated that virulent oncogenic MDV-1 is circulating in this region and the point mutation which occurs in the vIL8 gene may be one of the factors responsible for increasing the virulence of MDV and thereby vaccine failure. Few point mutations were observed and these mutations could be considered as the unique markers of the MDVs circulating presently in Punjab.