National Academy Science Letters - India

Not AvailableCyprinion semiplotum (order: Cypriniformes; family: Cyprinidae) is endemic to Southern Asia and has limited distribution in rivers of Eastern Himalayan region. It has an important role in ecology and is an important source of nutritious food and livelihood to the local people. In the recent past, the population of this species has declined due to various anthropogenic factors, and consequently, it has been categorized under vulnerable species. Genetic stock structure information would be useful to formulate appropriate management and conservation measures. The present study is carried out to characterize the Cyprinion semiplotum stocks collected from selected rivers in the state of Arunachal Pradesh, India, using mitochondrial ATPase 6/8 gene. A total of 14 haplotypes were found with nucleotide diversity in the range of 0.0013?0.0028. The result of AMOVA analysis also revealed that 99.44% of the genetic variation contained within stocks/populations and 0.56% occurred among populations/stocks. The results of the present study indicated that C. semiplotum stocks in north eastern part of India have low genetic differentiation and may be considered as a single panmictic population

Mitochondrial DNA Part B Resources

Not AvailableThe complete mitochondrial genome of the near threatened mahseer fish, Neolissochilus hexastichus, was characterized for the first-time using Ion Torrent NGS platform. The total length of the mitoge nome was 16,538 bp including a standard set of 22 transfer RNAs (tRNAs), 2 ribosomal RNAs (rRNAs), 13 protein-coding genes and a non-coding control region. Twenty-eight of the 37 genes are located on the light strand and, the remaining nine genes are situated on the heavy strand. Phylogenetic ana lysis showed the sister relationship between N. hexastichus and N. hexagonolepis. The mitogenome could be useful for phylogenetics, population genetics, and conservation of the mahseer

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Not AvailableCellular levels of specific transcripts or proteins are often measured in relation to a variety of biological events, using a selection of qualitative and quantitative methodologies. Changes in expression levels, measured in a native sentinel species may serve as biomarkers for the effects of environmental perturbations. A quantitative real-time reverse-transcriptase polymerase chain reaction study was conducted using freshwater air-breathing fish, Channa punctata (Bloch) as a test model for observing metallothionein mRNA expression pattern under the influence of varied concentrations of heavy metal, cadmium for an exposure span of 14 days. The findings revealed that metallothionein gene expression is a tissue specific phenomenon in C. punctata and liver is a prominent site for first-line defence during early exposure phase to cadmium, whereas kidney metallothionein mRNA indicates prolong presence of metal in the body.University Grants Commission, New Delhi, Indi

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Not AvailableComparative cytogenetic investigation of African catfish Clarias gariepinus (Burchell) and Asian catfish Clarias batrachus (Linn.) was undertaken using C- and NOR-banding techniques. The diploid chromosome number was found to be 56 and 50 respectively in C. gariepinus and C. batrachus. Besides this, there was a variation in chromosomal morphology between two species. NORs were present on one pair of chromosomes and C-bands were localised on seven pairs of chromosomes in both species. However, variations have been observed regarding the position of these bands. The present study indicated presence of variation between two catfishes in chromosome number, morphology and banding pattern. These variations can be used as cytogenetic markers for distinguishing two species and for finding chromosomal composition of the hybridsNot Availabl

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Not AvailableGenetic variability was assessed among three species of genus Channa, namely C. gachua, C. punctata and C. striata,using karyological tools including karyomorphology, silver nitrate and chromomycin A3 staining of nucleolar organizerregions (NORs) and C-banding. Additionally, sequence variation in partial 18S and divergent domain 1 of 28S ribosomal DNA was utilized for inter-species diversity assessment. Diploid chromosome numbers of 32, 40 and 52 in the three species were observed and the karyotype formula was derived as 18m + 12sm + 2st (fundamental arm number [FN] = 62); 6m + 2sm + 10st + 22t (FN = 48) and 12m + 10sm + 14st + 16t (FN = 86) in C. punctata, C. striata and C. gachua, respectively. Similarly, variations were also observed in number and location of silver and chromomycin A3 stained NORs and C-banding patterns. DNA sequencing generated sizes for 18S of 243, 248, 245 bp and for 28S of 401, 392 and 393 bp in C. gachua, C. punctata and C. striata, respectively. The results indicated that the cytogenetic and molecular markers are useful for the assessment of genetic diversity among the fish species and could provide valuable information for germplasm evaluation and ex situ conservation.Not Availabl

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Not AvailableRelationship among the mahseer species (Family: Cyprinidae) has long been debated in fish systematics. Present study concentrates on the nature of the phylogenetic relationship among the five mahseer species using the sequence of major ribosomal DNA (45S rDNA). We have covered rDNA sequence of approximately 5.2 kb per individual, 26.0 kb per species and 130.0 kb as a whole. We also characterized the 45S and 5S rDNA regions with respect to their nucleotide composition. For phylogenetic analyses, nucleotide sequences were divided into four datasets. First and second datasets contained 18S rDNA and ITS1 sequence, whereas third and fourth datasets consisted of ITS2 and complete 18S-ITS1-5.8S-ITS2-28S, respectively. The NJ tree was constructed for all the datasets. The mahseer species under study formed a monophyletic group well separated from the outgroup species. Similarly, the individuals of Neolissochilus hexagonolepis form monophyletic group with Tor species, indicating Neolissochilus as a sister genus of Tor. The findings from the present study provide greater insights into taxonomic status of mahseer, and set the stage for future investigations dealing with phylo-geography, taxonomy, conservation and co-evolution within this interesting and important group of fish.Department of Biotechnology, Ministry of Science and Technology, Government of India, New Delh

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Not AvailableAnalyses of nucleolar organizer region (NOR) site polymorphism using silver staining were carried out in 72 individuals of 5 geographically isolated populations of Tor putitora from India. All Ag-NORs analyzed were constituted by rDNA that was confirmed by the presence of positive fluorescence in situ hybridization (FISH) signals. Analyses of the extra NORs among the populations confirmed the hypothesis that multi-chromosomal NOR site polymorphism is not an exception but a rule. We found a negative correlation between the mean number of extra NORs and geographical distance from the Alaknanda River population, and a significant positive correlation between the genetic distances obtained by NOR data and geographical distances among the isolated populations. These findings suggest a single geographical origin of this NOR polymorphism, from which it might have radiated to neighboring populations before their isolation. The distribution of NOR site variation was compared with the sequence variation of the ITS1 region of major rDNA (45S) and the two were found to be positively related. Different mechanisms such as transposable elements adjacent to ribosomal genes, repetitive elements which could serve as a point for chromosome exchange, amplification of minor rDNA loci, and reinsertion of extrachromosomal rDNA amplified during oogenesis have been proposed to explain the apparent NOR site polymorphism. The high dispersion of NOR site variants within and among the populations suggests that whatever transposition phenomenon is responsible for repetitive DNA or NOR jumping, it could still be active in T. putitora.Not Availabl

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Not AvailableThe study was undertaken to identify sex chromosomes in Channa punctatus using human sex chromosome specific paint probes. Although the probes could detect sex chromosomes in human metaphase spread, no hybridization signals were detected on any of the chromosomes in C. punctatus. The results of the present study indicated that human sex chromosome paint probes were not useful for detecting sex chromosomes in Channa punctatusNot Availabl

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Not AvailableThe family Channidae is represented by 26 species, out of which 23 species are found in Asia. However, the taxonomy and phylogeny of the Channid fishes found in India are poorly understood. In the present study, eight species of Channa (Channa striata, Channa punctatus, Channa marulius, Channa gachua, Channa stewartii, Channa aurantimaculata, Channa barca and Channa bleheri) were investigated using partial sequences of 16S rRNA and Cytochrome c Oxidase subunit I (COI) of mitochondrial genes to differentiate among the eight species and study their relationships. The sequence analysis of the genes revealed two distinct groups, which are genetically distant from each other and exhibit identical phylogenetic resolution. The partial sequences of both the genes provided sufficient phylogenetic information to distinguish all the eight species of Channa.Not Availabl

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Not AvailableThe genotoxic effects of commonly used agricultural pesticides viz., carbosulfan, glyphosate, and atrazine, were evaluated in Channa punctatus (Pisces, Perciformes) using micronucleus (MN) test and induction of nuclear lesions (NL). The 96 h LC50 value were estimated by probit analysis as 0.27, 32.0 and 42.0 mg L(-1), respectively, for carbosulfan, glyphosate, and atrazine using semi-static bioassays. Based on these values, three sublethal test concentrations of carbosulfan (0.07, 0.13, 0.20 mg L(-1)), glyphosate (8.1, 16.3, 24.4 mg L(-1)) and atrazine (10.6, 21.2, 31.8 mg L(-1)) corresponding to ¼, ½ and ¾ of the LC50 of the pesticides respectively, were selected for exposure for 96 h. Peripheral blood samplings were taken at intervals of 24 h for assessment of MN and NL frequencies. Considerably higher genotoxic damage was induced by carbosulfan as compared to glyphosate and atrazine. There were significant effects (p < 0.01) of concentrations in all the treated groups. The induction of MN and NL was highest at 96 h pesticide exposure at all test concentrations. The nuclear abnormalities recorded in this study, such as blebbed-, lobed-, notched- and bi-nuclei, other than micronuclei, are indicators of genotoxic damage.The Academy of Science for Developing World (TWAS) and the Department of Biotechnology, the Ministry of Science and Technology, Government of India (DBT) for the post-doctoral fellowshi