Sequence analysis of the cleavage site-encoding region of the fusion protein gene of newcastle disease viruses obtained from pigeon, guinea fowl and quail

¹Division of Avian Diseases, Indian Veterinary Research Institute, Izatnagar–243122 (U.P.)

²Department of Research and Diagnosis of Poultry, Razi Vaccine and Serum Research Institute, P.O. Box: 11365 1558, Tehran, IRAN.

*Corresponding author; brs1762@ivri.up.nic.in