Cloning, sequencing and expression of cDNA encoding growth hormone from Indian catfish (Heteropneustes fossilis)

A tissue-specific cDNA library was constructed using polyA⁺ RNA from pituitary glands of the Indian catfishHeteropneustes fossilis (Bloch) and a cDNA clone encoding growth hormone (GH) was isolated. Using polymerase chain reaction (PCR) primers representing the conserved regions of fish GH sequences the 3′ region of catfish GH cDNA (540 bp) was cloned by random amplification of cDNA ends and the clone was used as a probe to isolate recombinant phages carrying the full-length cDNA sequence. The full-length cDNA clone is 1132 bp in length, coding for an open reading frame (ORF) of 603 bp; the reading frame encodes a putative polypeptide of 200 amino acids including the signal sequence of 22 amino acids. The 5′ and 3′ untranslated regions of the cDNA are 58 bp and 456 bp long, respectively. The predicted amino acid sequence ofH. fossils GH shared 98% homology with other catfishes. Mature GH protein was efficiently expressed in bacterial and zebrafish systems using appropriate expression vectors. The successful expression of the cloned GH cDNA of catfish confirms the functional viability of the clone.     

Cloning and sequencing of cDNA encoding the cat growth hormone

A cDNA encoding cat growth hormone (Fc) GH) has been isolated and sequenced. This is the first report of a feline GH nucleotide and deduced amino acid (aa) sequences. This cat pituitary cDNA resembles a typical mammalian pre-GH cDNA with its encoded mature hormone differing from dog GH only by a single as residue.     

Thermal tolerance and preference of the Indian catfish Heteropneustes fossilis

Synopsis The catfish Heteropneustes fossilis tolerates a wide range of temperatures. The minimal (7.9°C) and maximal (39.8°C) lethal temperature values obtained during summer are higher than the minimal (4°C) and maximal (37.7°C) lethal temperature values obtained during winter; gradual heating or cooling versus abrupt exposure to various temperatures did not produce significant differences. Catfish acclimated to temperatures of 28° (summer) or 16°C (winter) finally selected temperatures ranging from 31.3° to 32° C, when placed in a temperature gradient of 15° to 35° C. Catfish avoid temperatures below 25° C regardless of seasonal acclimatization.     

Gonadotropin releasing hormone (GnRH) neurones of triploid catfish,Heteropneustes fossilis (Bloch): an immunocytochemical study

Gonadotropin-releasing hormone (GnRH), a regulator of gonadal maturation in vertebrates, is primarily secreted by neurosecretory cells of the pre-optic area (POA) in the forebrain of teleosts. GnRH-immunoreactive (GnRH-ir) cells of this area demonstrate positive correlation in number and size of soma with gonadal maturity and directly innervate the pituitary in most teleosts. Gonadal development in triploid fish remains impaired due to genetic sterility. The gonadal immaturity in triploid fish may be due to low levels of gonadotropin and sex steroids during the vitellogenic phase of reproductive cycle. However, the nature of GnRH-ir cells in triploid fish is not yet known. Triploid catfish (H. fossilis) showed significant decrease (P<0.001) in size and number of immunoreactive-GnRH cells of POA and low immunoreactivity in pituitary in comparison to their diploid full-sibs during the late pre-spawning phase of ovarian cycle. This study suggests that low activity of GnRH-cells in triploid may be due to lack of positive feedback stimulation by sex steroids and/or reduced responsiveness of sensory cells to environmental cues required for gonadal maturation in teleosts.     

Purification and immunological characterization of catfish (Heteropneustes fossilis) metallothionein

Catfish hepatic metallothionein was purified to homogeneity by Sephadex G-75 gel filtration, DEAE-Sephadex A-25 column chromatography and preparative polyacrylamide gel electrophoresis. Induction by cadmium and zinc, characteristic UV spectrum, cadmium binding property and its low MW established that it was a metallothionein. Antibody was raised in rabbit against catfish metallothionein. Catfish antimetallothionein cross-reacted with other fish metallothioneins but not with chicken or rodent metallothionein. Catfish metallothionein is more electronegative as compared to mouse, rat, chicken or hamster metallothionein. Catfish MT appeared to aggregate readily on storage and to be less electronegative.     

Influence of temperature on ovarian recrudescence in the Indian catfish, Heteropneustes fossilis

Over a 60-day experiment during the preparatory phase of the reproductive cycle, ovarian weights increased with rise in temperature in Heteropneustes fossilis and oocyte diameters suggested an optimum temperature of 22° C for Stage II oocyte formation. The oocytes did not reach Stage II at 10° C. Atresia of Stage III oocytes occurred following 60 days of exposure at 30°C.     

Purification and immunological characterization of catfish (Heteropneustes fossilis) metallothionein

Summary Catfish hepatic metallothionein was purified to homogeneity by Sephadex G-75 gel filtration, DEAF-Sephadex A-25 column chromatography and preparative polyacrylamide gel electrophoresis. Induction by cadmium and zinc, characteristic UV spectrum, cadmium binding property and its low MW established that it was a metallothionein. Antibody was raised in rabbit against catfish metallothionein. Catfish antimetallothionein cross-reacted with other fish metallothioneins but not with chicken or rodent metallothionein. Catfish metallothionein is more electronegative as compared to mouse, rat, chicken or hamster metallothionein. Catfish MT appeared to aggregate readily on storage and to be less electronegative.Abbreviations MT Metallothionein - PBS Phosphate Buffered Saline - SDS Sodium Dodecyl Sulfat - PAGE Polyacrylamide Gel Electrophoresis Part of the work was reported in Proceedings of 54th Annual General Meeting of the Society of Biological Chemists, India, 1985.     

Fine structure and histochemistry of the venom gland in the Indian stinging catfish (Heteropneustes fossilis)

The venom glands of Heteropneustes lie deep in the epidermis at the sides of the pectoral fin spines, and consist of large cells that react positively to histochemical tests for proteins, histidine and tyrosine, negatively to periodic acid-Schiff and for serotonin and bombesin. The venom cells are of two types, appearing to have dense or lucent cytoplasm when seen by electron microscopy. The dense type has the better developed Golgi systems, the lucent type has more ribosomes. Both appear to differentiate from the basal layer of the epidermis. The epidermis over the glands has a zone with relatively few desmosomes and enlarged intercellular spaces. Both staining reactions and fine structure differentiate the venom gland cells from the club cells of the epidermis, to such an extent that they must be considered distinct secretory elements.     

Cestodes (Caryophyllidea) of the stinging catfish Heteropneustes fossilis (Siluriformes: Heteropneustidae) from Asia

The stinging catfish Heteropneustes fossilis (Bloch) (Siluriformes: Heteropneustidae) has been reported to harbor as many as 19 species of caryophyllidean tapeworms (Cestoda) of 11 genera in tropical Asia (Indomalayan zoogeographical region). However, a critical review of the species composition has shown that only 1 species, Lucknowia fossilisi Gupta, 1961 (Lytocestidae), is a specific parasite of H. fossilis. Three other species, Djombangia penetrans Bovien, 1926 (syn., Djombangia caballeroi Sahay and Sahay, 1977 ), Pseudocaryophyllaeus ritai Gupta and Singh, 1983 (syn. Pseudocaryophyllaeus lucknowensis Gupta and Sinha, 1984 ), and Pseudocaryophyllaeus tenuicollis (Bovien, 1926) Ash, Scholz, Oros and Kar, 2011 (syn. P. mackiewiczi Gupta and Parmar, 1982 ), were found only once. Lucknowia fossilisi is redescribed on the basis of new material collected in West Bengal and voucher specimens from Maharashtra, India. A total of 9 species of Capingentoides, Lucknowia, Lytocestus, Pseudoadenoscolex, Pseudocaryophyllaeus, Pseudoheteroinverta, and Sukhapatae are newly synonymized with L. fossilisi and previous synonymies of 9 other species, proposed by Hafeezulah (1993), are confirmed. Generic diagnosis of Lucknowia Gupta, 1961 is amended. In addition, 1 species of Pseudobatrachus and 2 species of the monotypic genera Pseudoneckinverta and Sudhaena are invalidated as nomina nuda.     

Effects of stress and food deprivation on catfish, Heteropneustes fossilis (Bloch)

No significant changes in plasma cortisol and plasma osmolarity (the indicators of primary and secondary response respectively) were observed when the blood samples were obtained from unanaesthetized, anaesthetized and stressed catfish, H. fossilis. The results suggest that the catfish is fairly hardy and not easily susceptible to stress by routine laboratory handling. The sustained plasma glucose levels and decreased liver and muscle glycogen concentrations during cessation of feeding of the catfish suggest that during period of food deprivation, it draws its energy through glycogenolysis. Hence, in any study dealing with carbohydrate metabolism, the catfish needs to be fed during acclimation and experimental periods.     

Cloning and nucleotide sequencing of sheep growth hormone cDNA.

cDNA was prepared from the mRNA isolated from sheep anterior pituitary glands. On cloning cDNA in E. coli, a clone coding full sequence of sheep pre-growth hormone was determined. The sequence for the sheep growth hormone (GH) is in agreement with the amino acid sequence of the protein determined previously except for the asparagine residue at position 99 rather than aspartic acid and the arginine residue at position 146 in place of threonine. The cDNA sequence presented is also in accordance with the genomic sequence for the sheep GH gene that has been reported.     

Ethological and haematological response of catfish,Heteropneustes fossilis,exposed to exogenous urea

Exposure of the airbreathing catfish,Heteropneustes fossilis to a sublethal concentration (200 mg/l) of urea resulted in blanching of skin, increased mucus secretion, hyperexcitability and higher rate of surfacing and gill ventilation. These changes were more pronounced during the first eight days of exposure as compared to the later period. A progressive increase in haematocrit, erythrocyte count, percentage of immature erythrocytes, mean corpuscular volume and erythrocyte sedimentation rate was observed during the 20 day exposure period. White blood cell-thrombocyte count registered a sharp decline initially upto 6 days but steadily increased afterwards. Initial decrease in the total leucocyte count was found to be mainly due to the decline in the number of lymphocytes and thrombocytes while the percentage of granulocytes (neutrophils and eosinophils) and monocytes showed a reverse trend.     

Cloning and sequencing of cDNA that encodes goat growth hormone

The cDNA that encodes goat growth hormone (gGH) was isolated from a goat pituitary cDNA library. The cDNA, about 880 base pairs long, had a coding sequence, 5'- and 3'-untranslated regions and a poly(A) chain. The cDNA could encode a polypeptide of 217 amino acids. The amino acid sequence homology between gGH and the sequences of bovine GH, rat GH and human GH was 99, 83 and 66%, respectively. By Northern blot hybridization, we found that the possible gGH gene is transcribed in the goat pituitary.