Vet World Vol.11 August-2018 Article-1
Research Article
Veterinary World, 11(8): 1025-1029
https://doi.org/10.14202/vetworld.2018.1025-1029
Genetic and phylogenetic analysis of the outer capsid protein genes of Indian isolates of bluetongue virus serotype-16
2. Department of Molecular and Cellular Engineering, Sam Higginbottom University of Agriculture Technology and Sciences (SHUATS), Allahabad - 211 007, Uttar Pradesh, India.
3. Division of Biological Standardization, Indian Veterinary Research Institute (IVRI) Izatnagar, Bareilly - 243 122, Uttar Pradesh, India.
Background and Aim: The aim of the study was to characterize bluetongue virus serotype 16 (BTV-16), recently isolated from different states of India. The evolutionary relationship of newly isolated BTV-16 and previously reported Indian and global BTV-16 isolates were compared using molecular analysis.
Materials and Methods: In the present study, five (n=5) BTV-16 isolates were used to amplify gene segment-2 and segment-6 encoding the outer capsid proteins VP2 and VP5, respectively. The amplified products were purified and sequenced by the Sanger sequencing method. The phylogenetic relationship and nucleotide identity of all five BTV-16 isolates were compared with previously reported Indian and global BTV-16 isolates. Nucleotide sequence data were aligned using the CLUSTAL W algorithm implemented in the MegAlign of DNASTAR program package (MegAlign 5.00, DNASTAR Inc., Madison, USA). Phylogenetic analyses were carried out using MEGA version 6.0 software with the best nucleotide substitution model.
Results: Phylogenetic analysis based on the VP2 and VP5 encoding genes, segregates Indian BTV-16 isolates in a distinct cluster with proximity to the Eastern topotype. Indian isolates make a monophyletic cluster with Eastern topotypes with Western topotype BTV-16 (BTV-16/NIG/AJ586694) occupying a separate cluster. Indian isolates were found to share 91.5%- 97.5% and 96.5%-98.9% identity at the nucleotide and deduced amino acid (aa) level, respectively, to the global BTV-16 isolates. There is a high degree of variation with the Nigerian isolate with 27.0-27.7% and 26.0-26.9% at the nucleotide and aa sequence level, respectively. These data suggest that Indian BTV-16 isolates might have evolved separately within the Eastern BTV topotype.
Conclusion: Phylogenetic analyses and nucleotide identity of BTV-16 isolates at the VP2 and VP5 gene encoded level indicate that isolates used in the present study might have evolved from a common Eastern topotype ancestor. The data presented in this study will be helpful for future selection of reference strains in a serological and molecular epidemiology study. Keywords: bluetongue virus, phylogenetic analysis, VP2 gene, VP5 gene.
Keywords: bluetongue virus, phylogenetic analysis, VP2 gene, VP5 gene.
How to cite this article: Saxena A, Biswas SK, Chand K, Naskar J, Chauhan A, Mohd G, Tewari N, Ain KU, Ramakrishnan MA, Pandey AB (2018) Genetic and phylogenetic analysis of the outer capsid protein genes of Indian isolates of bluetongue virus serotype-16, Veterinary World, 11(8): 1025-1029.
Received: 21-04-2018 Accepted: 13-06-2018 Published online: 01-08-2018
Corresponding author: Awadh Bihari Pandey E-mail: abpandey58@rediffmail.com
DOI: 10.14202/vetworld.2018.1025-1029
Copyright: Saxena, 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.