K. V. Lalitha

Differential gene expression profile of the hepatopancreas of white spot syndrome virus infected Fenneropenaeus indicus by suppression subtractive hybridization

Suppression Subtractive Hybridization was employed in order to identify the differentially expressed genes in the hepatopancreas of white spot syndrome virus infected Fenneropenaeus indicus. A forward subtracted cDNA library generated 356 clones following a white spot syndrome virus infection. A total of 345 clones with more than 100 nucleotides were selected for further analysis using bioinformatics tools after vector screening. Twenty-three contigs and 111 singletons were generated from a total of 134 consensuses. The consensuses, on a sequence homology search using BLASTX (NCBI), revealed that 74 (55%) of them had no significant match to reported sequences in the database, suggesting that they were found for the first time and are probably associated with shrimp immune function. Out of the remaining 60 (45%) consensuses, 43 had significant homology to known protein sequences in the database while 17 consensuses are homologous to unknown proteins in the database which are considered novel. The most abundant genes in the subtracted library were antimicrobial peptides accounting for 56 clones; among which one is a member of SNF2 family of proteins and another belonged to PfP1 family of proteins on analysis using Antimicrobial peptide predictor software. The other predicted genes in the subtracted library include signal transduction molecules (GTPase, Serine threonine kinase, Armadillo repeats etc), antioxidant enzymes (Cytochrome oxidase, Monomeric sarcosine oxidase and Catalase), active transporters (Nuclear Localization Signal [NLS], calcium ATPase, sodium glutamate symporter, Store-Operated Calcium Entry [SOCE] and ribonucleoprotein [RNP]) contributing to 19, 14 and 5 clones respectively. Three clones are homologous to reverse transcriptase; a first time report in shrimp and one each belong to cell adhesion molecule and Proteinase. InterProScan at EMBL, when used for an integrated search at PROSITE predicted; signal sequences and transmembrane regions for 13 clones. This is the first report on the differential gene expression in WSSV-infected F. indicus. The high expression of immune related genes in response to virus infection in shrimp will provide a new insight into the crustacean innate immunity. Further work on the functionality of the unknown genes in shrimps will give an overview on the role of the differentially expressed genes during viral infection and increase our understanding for developing antiviral measures by making use of the shrimp defense mechanism.

White spot syndrome virus infection: Threat to crustacean biodiversity in Vembanad Lake, India

Highlights • The prevalence of white spot syndrome virus (WSSV) among crustaceans from farmed, estuarine and marine environments surrounding the Vembanad Lake, India was detected using PCR.• A total of 308 samples from aquaculture ponds consisting of six species of crustaceans collected from five different farms were tested for the presence of WSSV.• WSSV was not detected from three species of deep sea crustaceans tested. The black tiger shrimp,• P. monodon had the highest incidence of WSSV among the species screened in farmed, estuarine and marine environments.

First draft genome sequence of a member of the genus mangrovibacter, isolated from an aquaculture farm in India.

ABSTRACT Mangrovibacter sp. MFB070, a Gram-negative, facultatively anaerobic, nitrogen-fixing bacterium, was isolated from an aquaculture farm in Cochin, India. Here, we report the first draft genome sequence of a member of the genus Mangrovibacter, which may help us to elucidate the evolutionary status of this genus. The draft genome sequence of the Mangrovibacter sp. consists of 5,361,682 bp, encoding 4,971 predicted coding sequences in 57 contigs.

Draft Genome Sequence of the Halophilic and Highly Halotolerant Gammaproteobacteria Strain MFB021.

ABSTRACT We report the 4.25-Mbp first draft sequence of Gammaproteobacteria strain MFB021, a moderate halophile isolated from petroleum-contaminated soil in Cochin, India. The genome of the strain MFB021 was sequenced to understand the mechanism of hydrocarbon degradation and the halophilicity of the bacterium.

Variations of structural protein sequences among geographical isolates of white spot syndrome virus

White spot syndrome virus (WSSV) is the causative agent of a disease that causes severe mortalities in cultured shrimp worldwide. The sequence of five structural genes of an Indian isolate of WSSV was compared with sequences from other WSSV isolates deposited in GenBank. Among the structural genes analyzed, the sequences of vp28 and vp19 had maximum divergence with nucleotide changes at ten different positions from twenty eight submissions for vp28 and six changes from seventeen submissions for vp19. The vp68, vp26, and vp281 genes were found to be highly conserved between isolates.

Occurrence of viral pathogens in Penaeus monodon post-larvae from aquaculture hatcheries

Viral pathogens appear to exert the most significant constraints on the growth and survival of crustaceans under culture conditions. The prevalence of viral pathogens White Spot Syndrome Virus (WSSV), Hepatopancreatic Parvo Virus (HPV), Monodon Baculo Virus (MBV) and Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) in Penaeus monodon post-larvae was studied. Samples collected from different hatcheries and also samples submitted by farmers from Kerala were analyzed. Out of 104 samples collected, WSSV was detected in 12.5% of the post-larvae samples. Prevalence of concurrent infections by HPV, MBV and WSSV (either dual or triple infection) was present in 60.6% of the total post-larvae tested. Out of the 51 double positives, 98% showed either HPV or IHHNV infection. HPV or IHHNV was detected in 11 post-larval samples showing triple viral infection. This is the first report of IHHNV from India. Result of this study reveals the lack of efficient screening strategies to eradicate viruses in hatchery reared post-larvae.

Nitrification Potential of Achromobacter xylosoxidans Isolated from Fresh Water Finfish Farms of Kerala, India

Over the decades, Aquaculture as a traditional practice has evolved to science based activity to meet the demands of food security as well as national economy. During 2016, world aquaculture production has projected to 73.8 mt with US

Bacteriophages for aquaculture: Are they beneficial or inimical

160.2 billion as an estimated first-sale value (FA0.2016). Total world aquaculture production accounted for 44.1% during 2014 and 31.1 % as compared in 2004. Feed is a crucial input for Semi –intensive and intensive aquaculture and usually contributes over 40-50% production costs but nearly 36% of the feed is excreted in the form of organic waste (Brune et al., 2003). The protein requirement of fish is about two to three times higher than that of mammals. Ammonium is one of the end products of protein metabolism (Walsh and Wright, 1995). In water, ammonia occurs in two forms which together are called total ammonia International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 08 (2018) Journal homepage: http://www.ijcmas.com