Genetic characterization of the non-structural protein-3 gene of bluetongue virus serotype-2 isolate from India

Vet World Vol.10 March-2017 Article-13

Research Article

Veterinary World, 10(3): 348-352

https://doi.org/10.14202/vetworld.2017.348-352

Raghavendra Sumanth Pudupakam¹, Shobana Raghunath², Meghanath Pudupakam³, and Sreenivasulu Daggupati¹

1. Department of Veterinary Microbiology, College of Veterinary Science, Sri Venkateswara Veterinary University, Tirupati, Andhra Pradesh, India.
2. Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia, USA.
3. Department of Biochemistry, Osmania University, Hyderabad, Telangana, India.

Background and Aim: Sequence analysis and phylogenetic studies based on non-structural protein-3 (NS3) gene are important in understanding the evolution and epidemiology of bluetongue virus (BTV). This study was aimed at characterizing the NS3 gene sequence of Indian BTV serotype-2 (BTV2) to elucidate its genetic relationship to global BTV isolates.

Materials and Methods: The NS3 gene of BTV2 was amplified from infected BHK-21 cell cultures, cloned and subjected to sequence analysis. The generated NS3 gene sequence was compared with the corresponding sequences of different BTV serotypes across the world, and a phylogenetic relationship was established.

Results: The NS3 gene of BTV2 showed moderate levels of variability in comparison to different BTV serotypes, with nucleotide sequence identities ranging from 81% to 98%. The region showed high sequence homology of 93-99% at amino acid level with various BTV serotypes. The PPXY/PTAP late domain motifs, glycosylation sites, hydrophobic domains, and the amino acid residues critical for virus-host interactions were conserved in NS3 protein. Phylogenetic analysis revealed that BTV isolates segregate into four topotypes and that the Indian BTV2 in subclade IA is closely related to Asian and Australian origin strains.

Conclusion: Analysis of the NS3 gene indicated that Indian BTV2 isolate is closely related to strains from Asia and Australia, suggesting a common origin of infection. Although the pattern of evolution of BTV2 isolate is different from other global isolates, the deduced amino acid sequence of NS3 protein demonstrated high molecular stability. Keywords: bluetongue virus, non-structural protein-3 gene, phylogenetic analysis.

Keywords: bluetongue virus, non-structural protein-3 gene, phylogenetic analysis.

How to cite this article: Pudupakam RS, Raghunath S, Pudupakam M, Daggupati S (2017) Genetic characterization of the non-structural protein-3 gene of bluetongue virus serotype-2 isolate from India, Veterinary World, 10(3): 348-352.

Received: 27-11-2016 Accepted: 23-02-2017 Published online: 23-03-2017

Corresponding author: Raghavendra Sumanth Pudupakam E-mail: prsumanth@gmail.com

DOI: 10.14202/vetworld.2017.348-352

Copyright: Pudupakam, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.