Murrel Channa Research Articles

The Coke Oven Effluent Channel of the Bhilai Steel Plant: Toxic Effects of its Wastewater on the Indian Murrel Channa punctatus Bloch

The Coke Oven Effluent Channel of the Bhilai Steel Plant: Toxic Effects of its Wastewater on the Indian Murrel Channa punctatus Bloch

Purification, characterization and expression of two vitellogenins in the Indian freshwater murrel Channa punctatus

The present study was undertaken to characterize different vitellogenins in Channa punctatus. Protein purification by gel chromatography followed by fast protein liquid chromatography (FPLC) revealed existence of two different Vg forms. Liquid chromatography tandem mass spectrophotometry (LC-MS/MS) suggested the existence of Vga and Vgb. Cloning of partial sequences of vga and vgb mRNA and phylogenetic analysis substantiated the existence of two vitellogenins. Real time PCR for vga and vgb genes from liver of estradiol-17β (E2) treated fish reveals difference in expression levels of transcripts of these two genes. vgb is expressed at lower dose of estradiol suggesting a higher sensitivity to estradiol. The present study thus proposes different regulatory control for the expression of these two genes and vgb as a superior biomarker than vga to assess exposure of C. punctatus to environmental estrogens.

Bioinformatics characterization of chemokine 14 from snakehead murrel Channa striatus

Bioinformatics characterization of chemokine 14 from snakehead murrel Channa striatus

Gene profiling and characterization of chemokine 20 from snakehead murrel Channa striatus

Gene profiling and characterization of chemokine 20 from snakehead murrel Channa striatus

An upstream initiator caspase 10 of snakehead murrel Channa striatus, containing DED, p20 and p10 subunits: Molecular cloning, gene expression and proteolytic activity

Caspase 10 (CsCasp10) was identified from a constructed cDNA library of freshwater murrel (otherwise called snakehead) Channa striatus. The CsCasp10 is 1838 base pairs (bp) in length and it is encoding 549 amino acid (aa) residues. CsCasp10 amino acid contains two death effector domains (DED) in the N-terminal at 2–77 and 87–154 and it contains caspase family p20 domain (large subunit) and caspase family p10 domain (small subunit) in the C-terminal at 299–425 and 449–536 respectively. Pairwise analysis of CsCasp10 showed the highest sequence similarity (79%) with caspase 10 of Paralichthys olivaceus. Moreover, the phylogenetic analysis showed that CsCasp10 is clustered together with other fish caspase 10, formed a sister group with caspase 10 from other lower vertebrates including amphibian, reptile and birds and finally clustered together with higher vertebrates such as mammals. Significantly (P < 0.05) highest CsCasp10 gene expression was noticed in gills and lowest in intestine. Furthermore, the CsCasp10 gene expression in C. striatus was up-regulated in gills by fungus Aphanomyces invadans and bacteria Aeromonas hydrophila induction. The proteolytic activity was analyzed using the purified recombinant CsCasp10 protein. The results showed the proteolytic activity of CsCasp10 for caspase 10 substrate was 2.5 units per μg protein. Moreover, the proteolytic activities of CsCasp10 in kidney and spleen induced by A. invadans and A. hydrophila stimulation were analyzed by caspase 10 activity assay kit. All these results showed that CsCasp10 are participated in immunity of C. striatus against A. invadans and A. hydrophila infection.

Status of alien fish species in the Western Ghats (India) as revealed from 2000-2004 surveys and literature analyses

Summary The objective of this study was to provide an inventory on alien fish species based on literature analysis and sampling surveys over 4 years, covering 465 locations of 25 river systems in Western Ghats, India. Thirty-two species of seven orders and 10 families have so far been recorded in the published literature as alien fishes in the Western Ghats. Cyprinidae encompassed the largest number of species with 14 members, followed by Poeciliidae with four and Channidae with three members. Nineteen alien fish species were delineated during the fish inventory surveys, of which the freshwater garfish Xenentodon cancila, snakehead murrel Channa striata and Mozambique tilapia Oreochromis mossambicus far exceeded other species in the number of river systems (23, 20 and 15 respectively) and locations (29, 26 and 24 respectively) where the species were encountered. Pool and reservoir habitats exhibited the highest distribution of alien fishes. Oreochromis mossambicus (pool, run, riffle and reservoir) and Poecilia reticulata (pool, run, cascade and reservoir) were found in the highest number of habitats. The results demonstrate that alien fishes have extensively colonized the river systems in the Western Ghats. A comprehensive risk assessment to ascertain the potential impacts of the alien fishes is very necessary to formulate appropriate management plans for control of alien fish invasions and conserve native fishes in the Western Ghats.

Vitellogenin genes in fish: differential expression on exposure to estradiol

Three types of vitellogenins (Vgs) namely vitellogenin A (VgA), vitellogenin B (VgB) and vitellogenin C (VgC) have been identified in fishes. The existence of VgA and VgB is reported in the Indian freshwater murrel Channa punctatus. Gene-specific primers were designed using available nucleotide sequences in National Centre for Biotechnology Information (NCBI), for amplification of VgA and VgB cDNA. Differential processing of Vgs is evident in many fishes. Adult male murrel expressed both the VgA and VgB genes when estradiol-17β (E(2)) is injected in vivo and Vg levels in blood quantified by Enzyme linked immunosorbent assay (ELISA) showed a dose-related response in such treatments. Cultured hepatocytes on treatment with E(2), however, expressed only VgB as detected by RT-PCR, suggesting different regulatory mechanism for the VgA and VgB genes.

Estradiol Induced Mechanisms Regulating Vitellogenin (VG) and Choriogenin Synthesis and Expression of VG in the Cultured Hepatocytes of Indian Freshwater Murrel Channa punctatus

Introduction: Vitellogenin (Vg) and Choriogenin (Chg) are femalespecific proteins, synthesized in the hepatocytes of teleosts. Several in vivo studies have shown that it is difficult to distinguish the primary effects of a compound from those induced secondarily because liver functions are under the influence of multiple endogenous factors. Therefore, in vitro hepatocyte systems present a better experimental model to investigate mechanism(s) by which Vg and chg are synthesized. Primary cultures of fish hepatocytes have been used to study hepatic structure and function, viz. endocrine regulation, Vg synthesis, hormone receptor expression, and toxicology. The Vg and Chg induction in cultured fish hepatocytes is clearly influenced by culture conditions (medium composition, temperature etc.) and culture system (hepatocyte monolayers, aggregates, liver slices etc.). The main advantages of the hepatocyte Vg and Chg assay are considered its ability to detect effects of estrogenic metabolites, since hepatocytes in vitro remain metabolically competent, and its ability to detect both estrogenic and anti-estrogenic effects. The aim of the present study was to understand the induction of Vg & Chg by estradiol (E2) and expression of Vg genes. Methods: Hepatocytes were isolated following the method of Rani et al.[1]. Hepatocytes were exposed to various doses of E2, optimum dose was selected and used for rest of experiments. Vg and Chg concentrations were determined in culture medium using standardized ELISAs [2] with few modifications. Cells exposed to a constant dose of E2 (500nM) in the presence of actinomycin D (3 and 6μg/ml) or cycloheximide (10 μg/ml). After 48 hrs media were collected from all the groups and processed for Vg and Chg estimation. Statistical Significance was calculated in between different doses of same treated groups by Mann-Whitney Wilcoxon test/student t-test; significance is given as p<0.005. Vg was extracted from the medium by PAGE and cut band was characterized by LC-MS/MS peptide mapping. Total RNA was isolated by TRIzol method from treated and non treated hepatocytes and processed for expression of Vg gene(s) by reverse transcription PCR (RT-PCR). E2 exposed hepatocytes were fixed and processed for localization of Vg and Chg in cytoplasm by immunocytochemistry and for ultrastructural analysis by TEM.

Optimum dietary protein requirement of striped murrel Channa striatus fry

This article deals with the dietary requirement of protein of Channa striatus fry, five different semi moist diets were formulated separately using semi purified ingredients (chicken intestine, fish waste and silk worm pupae). The highest specific growth rate (1.613%/day), food conversion ratio (1.526) weight gain (267.21%) average daily growth rate (0.824 %) and survival (96.66%) for fry were recorded in 55% of protein diet. Similarly carcass composition of fry differed according to the different protein levels. &nbsp; (Key words: Channa striatus fry, nutrition, growth, survival)

Optimum dietary protein requirement of striped murrel Channa striatus fry

This article deals with the dietary requirement of protein of Channa striatus fry, five different semi moist diets were formulated separately using semi purified ingredients (chicken intestine, fish waste and silk worm pupae). The highest specific growth rate (1.613%/day), food conversion ratio (1.526) weight gain (267.21%) average daily growth rate (0.824 %) and survival (96.66%) for fry were recorded in 55% of protein diet. Similarly carcass composition of fry differed according to the different protein levels. (Key words: Channa striatus fry, nutrition, growth, survival)

Opioid and non-opioid receptor-mediated immunoregulatory role of Leucine-enkephalin in teleost Channa punctatus

Leucine-enkephalin (Leu-enk) is an endogenous opioid peptide and highly conserved throughout the vertebrates. Despite its conserved nature, the immunoregulatory property of Leu-enk is explored only in mammals. The present study describes the immunomodulatory role of Leu-enk in a lower vertebrate, spotted murrel Channa punctatus. Leu-enk increased the percentage phagocytosis and phagocytic index, though its stimulatory effect on phagocytosis markedly decreased at concentrations higher than 10 −9 M. Moreover, it had bell-shaped stimulatory effect also on the superoxide production by phagocytes. On the other hand, Leu-enk showed bimodal effects on nitrite release. The lower concentrations of Leu-enk produced inhibitory effect, while higher concentrations had stimulatory effect on nitrite release. Interestingly, the Leu-enk-induced increase in nitrite release was unaltered by non-selective opioid receptor antagonist though the same completely antagonized the inhibitory effect of Leu-enk on nitrite release and the stimulatory effect on phagocytosis and superoxide production. This suggests that the stimulatory effect of Leu-enk on nitrite production is mediated by the non-opioid receptor. Further, δ-opioid receptor was precisely seen involved in mediating the stimulatory effect of Leu-enk on phagocytosis and superoxide production, or inhibitory effect on nitrite release. It can be concluded that Leu-enk regulates the innate immune response of splenic phagocytes acting via both opioid and non-opioid receptor in the fish C. punctatus.

Partial Biochemical Characterization and Iron Binding Capacities of Transferrin Variants of Air-breathing Murrel Channa punctata (Channidae: Channiformes)

Partial biochemical characterization of highly purified homozygous serotransferrin (Tf) phenotypes AA, BB and CC of air-breathing murrel, Channa punctata, was conducted. Molecular weight of each pure Tf variant was 75 kDa. Each Tf variant also had sialic acid as carbohydrate moiety of 10.5 kDa. Difference in spectra of ironapotransferrin complexes of C. punctata and human Tf were similar. Complex of each apoTf with iron had its maximum at 460 nm. Lack of a shoulder at 480 nm was characteristic of TfBB, while TfCC and TfAA had one shoulder at 480 nm and the other at 510 nm. The TfBB also had the highest total iron-binding capacity followed by TfCC and TfAA, respectively, though total saturation for each Tf was reached at 14 μM FENTA. Interestingly, the relative total iron-binding capacities of TfBB and CC showed a positive correlation with the allelic composition of populations, which were the sources of sera. The significance of iron binding capacities of Tf variants along with some other factors on the population structure of C. punctata is discussed.

Influence of Human Chorionic Gonadotropin on Maturation in Striped Murrel, Channa striatus

Gonadal development, gonadosomatic index (GSI), oocyte diameter, fecundity, histology and level of serum steroid hormones (testosterone and estradiol-17β) were observed in captive striped murrel (Channa striatus Bloch) implanted with human chorionic gonadotropin (HCG) capsules and cholesterol capsules as control for a period of five months after implantation. HCG implants induced a significant increase in the GSI of male and female fish. The GSI values were highest in the fourth month (December) and lowest in the first month (September) in HCG implanted fishes. Variation in ova diameter of control and HCG implanted fishes revealed the presence of large size ova in HCG implanted fishes throughout the study period. Similarly, a significant increase in the fecundity of HCG implanted fishes was also observed. Fecundity was highest in December (15415 eggs) in HCG implanted fish, whereas only 2245 eggs were observed from control fish in the above sampling period. In control fish, only perinucleolar and primary oocytes were observed throughout the study period. Similarly, in testis, spermatogonia and few spermatocytes were observed till the end of the study period. Histological examination of the gonads of HCG implanted fish showed that numerous oogonia were present in the ovary after one month of HCG implantation which continued to develop into vitellogenic oocytes in the third and fourth months. The ovary in the fifth month of sampling of HCG implanted fish consisted of oocytes having completed the process of vitellogenesis. The testicular histology of HCG implanted fish showed primary spermatocytes in the first month and testis contained a large reserve of primary spermatocytes and spermatids in the second and third months. A large number of spermatids were observed in the testis in the fourth month of sampling and the testis in the fifth month of sampling predominantly contained spermatozoa. Serum testosterone level was highest (18ng•ml-1) during the fourth month (December) in HCG implanted male fish and serum estradiol-17β level was highest (61.5pg•ml-1) in the third month in HCG implanted female fish. The results of the present work can be used as a reference study for controlled breeding and reproduction of striped murrel, C. striatus.

Expression of 20β-hydroxysteroid dehydrogenase and P450 17α-hydroxylase/c17–20 lyase during hCG-induced in vitro oocyte maturation in snake head murrel Channa striatus

Partial cDNAs encoding carbonyl reductase like 20beta-hydroxysteroid dehydrogenase (20beta-HSD) and P450 17alpha-hydroxylase/c17-20 lyase (CYP17) were isolated from the ovary of snake head murrel and they exhibited high sequence identity to the Nile tilapia and rainbow trout, respectively. A low transcript level of both 20beta-HSD and CYP17 were detected in pre-vitellogenic follicles, while the transcript level was high in full-grown immature follicles. In hCG-induced in vitro oocyte maturation, we found a significant increase in 20beta-HSD transcript level after 2 h. The CYP17 transcripts also showed a considerable increase following hCG-induction compared to saline-treated controls. On the other hand, Western blot analysis demonstrated no significant change in the CYP17 protein level during hCG-induced in vitro oocyte maturation. Taken together, we suggest that in addition to 20beta-HSD, the CYP17 might have a role in the shift in steroidogenesis during meiotic maturation of snake head murrel.

Skeletal deformities of few freshwater fishes from Bhavani River, Tamil Nadu

Manuscript 1145; Received 5 February 2004; Revised received 31 May 2004; Finally accepted 10 July 2004; © Zoo Outreach Organisation; www.zoosprint.org 1628 Deformities in teleosts are occasionally found in natural and/ or wild population. Such phenomenon is quite common among the animals kept in zoos for captive propagation (Sennar, 1980; Tutman et al., 2000). Several studies have focused on the deformities of the skeletal region, and a wide range of causes has been noticed, including genetic variance (hereditary factors), inbreeding depression, significant ecosystem changes viz., temperature, pH, parasitism, nutritional deficiencies and environmental contamination (from pollutants) (Orska, 1962; Koumoun-douros et al., 1997). Numerous reports are available regarding the present study in other species viz., Cirrhinus mrigala and Hypothalmichthys molitrix (Panday & Awasthi, 1994) probably due to inbreeding depression. Similar abnormal features have also been observed among a few endangered fish species, namely, Salmo trutta (Poynton, 1987), Micropterus dolomieni (Avyle et. al., 1989) and Oncorhynchus mykiss (Madsean & Dalsgard, 1999). The present study reports the skeletal deformities found in wild populations of a few freshwater catfishes Mystus cavasius, Ompok bimaculatus and Heteropneustes fossilis, murrel Channa striatus and C. puntatus and featherback Notopterus notopterus.

Genetic Structure of Natural Populations of Air-breathing Murrel Channa punctatus Bloch in the Rohilkhand Plains of India

Genetic Structure of Natural Populations of Air-breathing Murrel Channa punctatus Bloch in the Rohilkhand Plains of India

Chemokine/chemokine receptor nomenclature.

Chemokine/chemokine receptor nomenclature.

Induced spawning of the striped murrel Channa striatus using pituitary extracts, human chorionic gonadotropin, luteinizing hormone releasing hormone analogue, and ovaprim(r)

Induced spawning of the striped murrel Channa striatus using pituitary extracts, human chorionic gonadotropin, luteinizing hormone releasing hormone analogue, and ovaprim(r)

Seasonal changes in the pituitary gonadotrops during tha annual reproductive cycle of the Murrel Channa punctatus (Bloch)

Foram observadas mudanças sazonais na estrutura e comportamento dos hormônios gonadotrópicos pituitários durante o ciclo reprodutivo anual de Channa punctatus. Os hormônios gonadotrópicos demonstram mudanças morfológicas marcantes na forma da granulação, degranulação e vacuolisação com o ciclo sexual sugerindo sua tendência de armazenamento e liberaçào durante atividades gonadais.

Mercuric chloride induced alterations in the intestinal transport of glucose and fructose in the fresh water murrel Channa punctatus

The effect of five concentrations of mercuric chloride (10 mM, 5 mM, 1 mM, 0.5 mM, and 0.l mM) on the uptake of glucose and fructose from the intestine of the fresh water murrel Channa punctatus after 15, 30 and 60 min was studied. Intestinal glucose and fructose transport was also assessed in fish exposed to a sublethal concentration (3 μg l−1) of mercuric chloride for 10 and 30 days. The results show that the uptake of glucose and fructose from the intestine was reduced by all five concentrations of mercuric chloride. Maximum reduction was observed after 60 min of exposure to 10 mM mercuric chloride. The rate of absorption of glucose and fructose increased with time in controls and in all concentrations of mercury except the highest concentration (10 mM) where the rate of absorption decreased gradually. The reduction in the rate of absorption of the two sugars was not dependent on the concentration of mercury in the instilled medium. In fish exposed to mercuric chloride in laboratory media, the reduction of glucose and fructose absorption was greater after 30 days of exposure than after 10 days.