International Journal of Biotechnology Research Vol. 3(3), pp. 035-044, April 2015 ISSN 2328-3505 ©2015 Academe Research Journals

Full Length Research Paper

Molecular characterization and phylogenetic analysis of Family Adenoviridae from marine environment as inferred from the hexon protein gene

Dhirendra Kumar Singh and Swapna P. Antony*

National Centre for Aquatic Animal Health, Cochin University of Science and Technology, Cochin-682016, Kerala, India.

*Corresponding author. E-mail: swapnapantony@gmail.com, swapnapantony@cusat.ac.in. Tel: + 914842381120; Fax: + 914842381120.

Accepted 6 April, 2015

Abstract

The marine environment, covering 70% of the planet’s surface, is estimated to contain 10³⁰ viruses. Despite their great importance in the marine environment, virtually very little is known about marine viral biodiversity or the evolutionary relationships of marine and non-marine viruses. The present study is aimed at molecular characterization and phylogenetic analysis of the viral Family Adenoviridae from the marine environment, based on the hexon protein gene. Briefly, 50 L of sea water was purified and concentrated by a combination of tangential flow filtration, flocculation and centrifugation. Metagenomic DNA was extracted from the viral particles and PCR amplification was performed using specific primers designed for hexon protein gene of adenoviruses. Positive amplicons were cloned and sequenced. Sequences were analysed using GeneTool, BioEdit, ExPASy, ClustalW, GeneDoc and Mega 5.0 programmes. Partial hexon protein amplicon of 254 bp fragment encoding hexon protein of 84 amino acids could be recovered from the metagenomc viral DNA (KJ958986). Phylogenetic relationship of the newly identified hexon protein gene was constructed employing neighbour joining method based on already available hexon protein sequences in GenBank. The results of phylogenetic analysis confirmed the basal placement of the newly identified hexon protein gene in the Adenoviridae family. The present study shows that the newly identified adenovirus from marine environment is more closely related to adenoviruses isolated from Ovine and Bovine sources than to other adenoviruses from human sources. The present study provides a clearer insight into adenoviridae present in the marine system.

Key words: Adenovirus, marine viruses, hexon protein, metagenomics, phylogeny.