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Verma D.K.,National Bureau of Fish Genetic Resources ICAR | Rathore G.,Central Institute of Fisheries Education
Journal of General and Applied Microbiology | Year: 2013

Flavobacterium columnare is currently one of the important bacterial pathogens causing columnaris disease in several farmed fish species across diverse geographies. A presumptive columnaris disease outbreak in farmed catla, Catla catla (Hamilton), was investigated with the aim of isolating and identifying the causative pathogen. F. columnare (strain RDC-1) was isolated from gills of infected fish and identified by conventional biochemical methods, and through species specific polymerase chain reaction and sequencing of the 16S rDNA for molecular identification. Strain RDC-1 belonged to genomovar II with ≥99% similarity to available 16S rDNA sequences of F. columnare, and also shared ≥70% DNA-DNA relatedness with known strains of F. columnare. Bath immersion studies of RDC-1 showed development of columnaris disease in catla fingerlings within 7 days, with a cumulative mortality of 83.3%. This is the first molecular confirmation of Flavobacterium columnare as a fish pathogen of farmed Catla catla in India.

Diwan A.D.,Indian Council of Agricultural Research | Ayyappan S.,Indian Council of Agricultural Research | Lal K.K.,National Bureau of Fish Genetic Resources ICAR | Lakra W.S.,National Bureau of Fish Genetic Resources ICAR
Indian Journal of Animal Sciences | Year: 2010

Cryopreservation of gametes is one of the important ex situ methods of conservation of germplasm and has wide ranging applications in aquaculture and fisheries management. Though sperm cryopreservation has been a success in fishes, yet developing successful protocols for eggs and embryo cryopreservation still remains elusive. Despite successful sperm cryopreservation protocol known for more than 200 fish species, the adoption of the technique at commercial level for fish seed production has been limited. High degree of variability in the procedural requirements and success not only between the species but at times within the species, is considered one of the limiting factors in its utilization. The present paper records the status of gamete cryopreservation in fish species. The paper provides a comprehensive review of various aspects of milt cryopreservation such as milt collection, sperm quality and viability assessment, extender compositions, cryoprotectants equilibration periods, freezing rates, thawing of cryopreserved milt and fertilization of eggs and ultrastructural studies on damages in cryopreserved spermatozoa. The paper also provides a brief review of cryopreservation of fish embryos and embryonic stem cells.

Mohindra V.,National Bureau of Fish Genetic Resources ICAR | Tripathi R.K.,National Bureau of Fish Genetic Resources ICAR | Singh A.,National Bureau of Fish Genetic Resources ICAR | Singh B.,Chandigarh Institute of Microbial Technology
Fish and Shellfish Immunology | Year: 2013

A novel member of Cystatin superfamily was identified from Indian catfish, Clarias batrachus, in response to oxidation stress induced by environmental hypoxia. Integrated genomic approaches, expression profiling and computational techniques showed that CbCystatin had putative cystatin/monelin like domain and might be a transmembrane and/or intermediate protein in signaling pathways. CbCystatin was found to be clustered into family 2 Cystatins. At transcriptional level, its expression was significantly up-regulated in response to short as well as long periods (more than 20 fold) of hypoxia, suggesting its positive association with oxygen concentrations lower than physiological concentrations. © 2012 Elsevier Ltd.

Luhariya R.K.,National Bureau of Fish Genetic Resources ICAR | Lal K.K.,National Bureau of Fish Genetic Resources ICAR | Singh R.K.,National Bureau of Fish Genetic Resources ICAR | Mohindra V.,National Bureau of Fish Genetic Resources ICAR | And 4 more authors.
Molecular Biology Reports | Year: 2012

The present study examined partial cytochrome b gene sequence of mitochondrial DNA for polymorphism and its suitability to determine the genetic differentiation in wild Labeo rohita. The 146 samples of L. rohita were collected from nine distant rivers; Satluj, Brahmaputra, Son, Chambal Mahanadi, Rapti, Chauka, Bhagirathi and Tons were analyzed. Sequencing of 307 bp of Cyto b gene revealed 35 haplotypes with haplotype diversity 0.751 and nucleotide diversity (π) 0.005. The within population variation accounted for 84.21% of total variation and 15.79% was found to among population. The total Fst value, 0.158 (P<0.05) was found to be significant. The results concluded that the partial cyto b is polymorphic and can be a potential marker to determining genetic stock structure of L. rohita wild population. © Springer Science+Business Media B.V. 2011.

Mohindra V.,National Bureau of Fish Genetic Resources ICAR | Tripathi R.K.,National Bureau of Fish Genetic Resources ICAR | Yadav P.,National Bureau of Fish Genetic Resources ICAR | Singh R.K.,National Bureau of Fish Genetic Resources ICAR | And 2 more authors.
Molecular Biology Reports | Year: 2015

Heat shock proteins (Hsps) are typically associated with stress response and tolerance. The Indian catfish, Clarias batrachus, is a freshwater air-breathing hypoxia tolerant teleost and is potentially important catfish species for aquaculture and for its economic value as food. The present study aimed at determining the transcriptional response of three Hsps, CbHsc71, CbHsp90α and CbHsp10 in hypoxia tolerant Indian catfish, C. batrachus, under experimental and natural hypoxia. The expression profile of above three genes were studied under different periods of hypoxia, through qRT-PCR. Primers were designed from ESTs obtained through SSH libraries constructed from hypoxia treated fishes. The Hsp10 ESTs and deduced protein was in silico characterized for its ORF and for its physical and chemical properties, respectively, using GeneScan, blastp, scanprosite, superfamily and other softwares. A phylogenetic tree was constructed based on deduced amino acid sequences of Hsc71, Hsp90α, Hsp90β of Homo sapiens and other fishes along with CbHsp10 protein in MEGA4. The deduced protein sequences of CbHsp10 was found to have characteristic Hsp10 family signatures, and it is proposed for inclusion of methionine in the consensus sequences of Hsp10 family signature, after the “proline” residue. At transcription level, these genes were found to be differentially regulated under hypoxia stress, in different tissues of C. batrachus. The CbHsc71 and CbHsp90α were up-regulated after short and long-term hypoxia, whereas CbHsp10 was significantly down-regulated after short-term hypoxia. The differential expression of these Hsps may play a role in protection and survival under hypoxia induced oxidative stress in C. batrachus. © 2015, Springer Science+Business Media Dordrecht.

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