| effect of nisin in saturated brine and storage on the quality of dried bolti fish (tilapia nilotica). | bolti fish which had been eviscerated and brined in a saturated brine containing 0.5 mg nisin/g of fish for 10, 15 and 20 min, were divided into two parts, one for dehydration and the second for sun-drying. the dried products were packed in polyethylene bags and stored at room temperature for 3 months. the quality attributes were estimated during processing and monthly during storage. total volatile bases showed a certain increase after salting, drying and throughout storage periods; thiobarbitu ... | 1976 | 785268 |
| fish transgene expression by direct injection into fish muscle. | the ability of a promoter sequence to drive expression of a reporter gene can be determined by direct injection of copies of the cloned sequence into fish muscle, followed by biopsy of muscle from the site of injection. we describe a set of experiments in which copies of the constructs fv1 and fv2, both comprising a carp beta-actin promoter sequence spliced to the bacterial reporter gene cat, were injected into the muscle of tilapia fish )oreochromis niloticus) of between 5 and 8 cm body length. ... | 1992 | 1308819 |
| evidence for the kidney as an important source of 5'-monodeiodination activity and stimulation by somatostatin in oreochromis niloticus l. | radioimmunoassay of 3,5,3'-triiodothyronine (t3) and thyroxine (t4) in the thyroidal region of mature male oreochromis niloticus revealed stores of t4 but negligible levels of t3, yielding a very low t3/t4 ratio (0.3%). 5'-deiodination (5-d) of t4 into t3 was examined in liver and kidney homogenates in vitro by radioimmunoassay of t3 with t4 as substrate. in both organs, the 5'-d activity was temperature dependent: at 4 degrees c, t3 production was below the level of detection and maximal in bot ... | 1992 | 1362169 |
| somatostatin increases plasma t3 concentrations in tilapia nilotica in the presence of increased plasma t4 levels. | an injection of ovine growth hormone, porcine follicle stimulating hormone, and bovine thyrotropin stimulating hormone increased in tilapia nilotica plasma concentrations of thyroxine (t4) and reverse triiodothyronine (rt3) after 4 and 8 hr, whereas plasma concentrations of t3 were unaffected. an injection of somatostatin (srif) alone did not influence thyroid hormone levels. if, however, srif was injected together with these hormones, which raised plasma t4, or together with t4 itself, an incre ... | 1991 | 1679027 |
| purification of tilapia thyrotropin from a crude pituitary homogenate by immunoaffinity chromatography using a matrix of antibodies against porcine follicle-stimulating hormone. | an immunoadsorbent matrix using antibodies against porcine follicle-stimulating hormone (pfsh), a high heterothyrotropic stimulant in tilapia, was used to purify tilapia thyrotropic hormone (t-tsh) from crude pituitary extracts. a homologous bioassay monitored tsh bioactivity during the purification. thyroid hormones (thyroxine, t4; triiodothyronine, t3; and reverse triiodothyronine, rt3) and testosterone were measured in vivo in tilapia nilotica. tsh activity eluted as one major peak at ph 2.8 ... | 1991 | 1783265 |
| measurement and prediction of digestible energy values in feedstuffs for the herbivorous fish tilapia (oreochromis niloticus linn.). | digestible energy (de) values were measured in a selection of feedstuffs for the tilapia (oreochromis niloticus linn.) and used to develop equations for predicting de values of a wider range of feedstuffs from chemical analyses. preliminary work examined the influences of substitution level in a reference diet and adaptation over time on de values for soya-bean meal. length of adaptation period significantly affected de values (p less than 0.01), but substitution level, over the range 200-600 g ... | 1991 | 1931904 |
| stimulation of thyroid function by several pituitary hormones results in an increase in plasma thyroxine and reverse triiodothyronine in tilapia (tilapia nilotica). | in this study, intravenous injection of several doses of porcine follicle stimulating hormone (pfsh: 0.002, 0.01, 0.05, and 0.5 micrograms/g body wt), bovine tsh (btsh: 0.5 micrograms/g body wt), and ovine growth hormone (ogh: 0.04, 0.02, and 0.4 microgram/g body wt) stimulated an increase in plasma thyroxine (t4) and reverse triiodothyronine (rt3) in tilapia. this effect occurred in a dose-dependent manner. pfsh was the most potent in stimulating thyroid function. the dose of 0.002 microgram pf ... | 1990 | 2125568 |
| accumulation of metals and histopathology in oreochromis niloticus exposed to treated nnpc kaduna (nigeria) petroleum refinery effluent. | accumulation of heavy metals and histopathology were observed in oreochromis niloticus exposed to treated petroleum refinery effluent from the nigerian national petroleum corporation, kaduna. analysis of fish metal burden showed that the fish concentrated trace metals a thousand times above the levels existing in the exposure medium. some metals were preferentially accumulated more than others and the accumulation was, in decreasing order, pb, fe, zn, cu, mn, cr, ni, and cd. whole fish metal bur ... | 1990 | 2338061 |
| aquatic fungi associated with seven species of nile fishes (egypt). | ten identified species in addition to 2 unidentified species of achlya and pythium which belong to seven zoosporic fungal genera (aquatic freshwater fungi) were recovered during this investigation. the fish species with most zoosporic fungi (5 species and 3 genera) was tilapia nilotica. the fish species with least fungi were bagrus bayad and syndontis schall (yielded only one species each). mormyrus kannum did not give any zoosporic fungal species. some aquatic fungi emerged only from internal o ... | 1989 | 2618196 |
| tilapia prolactin: molecular cloning of two cdnas and expression in escherichia coli. | we have isolated cdna clones encoding tilapia prolactin (tiprl) from a cdna library prepared from tilapia (oreochromis niloticus) anterior pituitary glands. a trout prl cdna fragment was used as hybridization probe to select the recombinant plasmids carrying the tiprl coding sequence. two types of prl cdna were isolated and their complete nucleotide sequence determined. the larger cdna (tiprl-i) codes for a polypeptide of 212 amino acids, including a putative signal sequence of 24 amino acids, a ... | 1989 | 2670495 |
| tilapia growth hormone: molecular cloning of cdna and expression in escherichia coli. | a cdna library was prepared from poly(a)+rna extracted from tilapia oreochromis niloticus anterior pituitaries. the recombinant clones carrying the cdna sequence of tilapia growth hormone (tigh) were selected using a fragment of the trout growth hormone (tgh) cdna as hybridization probe. the nucleotide sequence of the full-length tigh cdna was determined. this cdna encodes a protein of 204 amino acids, including the putative signal peptide of 17 amino acids. mature tigh cdna was inserted in an e ... | 1989 | 2670496 |
| [aeromonas hydrophila-related septicemia in the nile tilapia oreochromis niloticus]. | from diseased wild and cultured oreochromis niloticus in lower egypt, 17 aeromonas hydrophila isolates were recovered. the mortality was between 10% and 70% in among cultured fish. the course of the disease ran in an acute manner. for cultured fish, the disease outbreaks were found mainly in winter and for the wild nile fish, mortalities were observed in late spring and summer. additionally wild fish were affected with ectoparasites. the ld50 values of the isolates ranged between 10(3) and 10(7) ... | 1989 | 2719631 |
| [detection of the hepatitis a virus in fish at a fish farm]. | in this study, we have researched enteroviruses in digestive tract and gills of 106 fishes from farming station, belonging to the five most eaten species in ivory coast (chrisychthys walkeri, chrisychthys nigrodigitatus, tilapia nilotica, tilapia guineensis, sarotherodon melanotheron). hepatitis a virus was found in 12 fishes (11.3%), five times in gills, three times in digestive tract and four times in both. the two species apparently the more contaminated, were chrisychthys nigrodigitatus, sar ... | 1987 | 2836101 |
| thick filaments of fish myosin and its actin-activated mg-atpase activity. | 1. tilapia (tilapia nilotica) myosin forms short, mini-filaments, and are easily disassembled upon addition of atp showing no saturated activation in its actin-activated mg-atpase activity. 2. the presence of 5-10 mm mgcl2 allows tilapia myosin to form native thick-filaments and are resistant to atp. 3. the rod portion of tilapia myosin molecule is responsible for its characteristic filament forming ability. 4. the similar filament forming ability as tilapia myosin was suggested for other fish m ... | 1988 | 2977748 |
| columnaris infection among cultured nile tilapia oreochromis niloticus. | flexibacter columnaris was isolated from 13 cultured oreochromis niloticus showing respiratory disorders. the isolates developed typical swarming rhizoid colonies on cytophaga agar medium. antibiotic sensitivity test revealed the susceptibility of f. columnaris isolated to oxytetracycline, chloramphenicol and erythromycin. a marked difference in the pathogenicity of seven tested isolates was observed: two were highly virulent, one was moderately virulent and four were avirulent. no experimental ... | 1988 | 3232970 |
| [high mortality of the nile tilapia oreochromis niloticus caused by providencia rettgeri]. | | 1987 | 3632601 |
| protective efficacy of aeromonas hydrophila vaccines in nile tilapia. | protection and serum antibody production against aeromonas hydrophila was examined in nile tilapia, tilapia nilotica (l.). intraperitoneally injected formal in-killed and freunds complete adjuvant vaccines were compared using different doses (2.9 x 10(7) and 2.9 x 10(9) cfu/ml). upon challenge, the protective ability and antibody titers resulting were significantly different between vaccinated and unvaccinated groups. a relative level of protection of 100% was obtained within two-weeks, and a ma ... | 1986 | 3765355 |
| urotensin ii-immunoreactive neurons in the caudal neurosecretory system of freshwater and seawater fish. | antiserum generated against synthetic urotensin ii of the goby, gillichthys mirabilis, was used to localize urotensin ii in the caudal neurosecretory system in six species of freshwater teleosts: cyprinus carpio, carassius auratus, oreochromis mossambicus, oreochromis niloticus, salmo gairdneri and plecoglossus altivelis, and six species of seawater teleosts: acanthogobius flavimanus, pagrus major, parapristipoma trilineatum, trachurus japonicus, seriola dumerili and seriola quinqueradiata. in t ... | 1985 | 3884162 |
| myxosporean infections in cultured tilapias in israel. | five new species of myxosporean parasite are described from cultured tilapias in israel. these are: myxosoma sarigi, myxosoma equatorialis, myxobolus israelensis, myxobolus agolus, and myxobolus galilaeus. the first four were found in hybrids of oreochromis aureus x oreochromis niloticus while myxobolus galilaeus was found in sarotherodon galilaeus. in addition, m. sarigi, m. israelensis, and myxobolus sp. were also found in s. galilaeus. in the light of the present study, the taxonomy of myxosp ... | 1985 | 3989749 |
| the impact of the exotic fish gambusia affinis (baird and girard) on some natural predators of immature mosquitoes. | the effects of gambusia affinis on some suspected predators of mosquitoes were studied for a period of 12 months. a list of such predators was given. the most abundant invertebrate predators were odonata, followed by hemiptera and ephemeroptera and the least common were coleoptera. the population density of mosquito predators, with exception of notonectidae and the fish oreochromis niloticus, was markedly reduced in the presence of g. affinis. application of aerial pesticides reduced the populat ... | 1985 | 4032526 |
| occurrence of bacterial pollution indicators in boulti (tilapia nilotica linn.) fish. | a study was made for the occurrence of coliform and streptococcal groups on the skin surface (32 samples), gills (32 samples), intestinal tract (4 samples) and raw fish flesh (4 samples) and raw fish flesh (4 samples) of boulti fish (tilapia nilotica linn.), a fresh water fish caught from nasser's lake in aswan. streptococcus group was detected in 13 samples taken from fish surface, 12 samples out of 32 swabs from gills. all intestine samples and raw fish flesh were positive for the streptococcu ... | 1982 | 6755931 |
| vitellogenins of oreochromis niloticus: identification, isolation, and biochemical and immunochemical characterization. | two native forms of vitellogenin (eip1 and eip2) were identified in the plasma of oreochromis niloticus. they were present in females and were estrogen-inducible in males. both were phosphoglycolipoproteins and both immunoreacted with the antiserum raised against egg proteins. two prominent bands (eipp1 and eipp2; corresponding to 185 and 120 kda, respectively), observed on sodium dodecyl sulfate-polyacrylamide gels, were induced by estradiol treatment of males and immunoreacted with the antiser ... | 1995 | 7561725 |
| induction and purification of cytochrome p450 1a1 from 3-methylcholanthrene-treated tilapia, oreochromis niloticus x oreochromis aureus. | pretreatments of freshwater fish tilapia, oreochromis niloticus x o. aureus, with 3-methylcholanthrene (3-mc) and polychlorinated biphenyls (pcbs) increased liver microsomal cytochromes p450 (p450) and b5 contents, benzo[a]pyrene hydroxylation, and 7-ethoxyresorufin and 7-ethoxycoumarin o-dealkylations. the pretreatments also increased gill microsomal benzo[a]pyrene and 7-ethoxyresorufin oxidations. immunoblot analysis of liver and gill microsomes revealed that 3-mc and pcbs induced a protein re ... | 1995 | 7574707 |
| hypothalamic and thyroidal regulation of growth hormone in tilapia. | a radioimmunoassay (ria) for recombinant tilapia growth hormone (gh) was established and validated. the ability of various hypothalamic factors to regulate gh secretion in the tilapia hybrid (oreochromis niloticus x oreochromis aureus) was studied. somatostatin1-14 (srif1-14; 10-100 micrograms/kg) was found to reduce circulating gh levels in a dose-dependent manner. srif1-14 (0.1-1000 nm) inhibited gh release from perifused pituitary fragments (ed50 0.83 nm). human growth hormone-releasing hormo ... | 1995 | 7713377 |
| the prolactin of european sea bass (dicentrarchus labrax l.): cloning of cdna and efficient expression in escherichia coli. | the cdna encoding sea bass (dicentrarchus labrax) prolactin (sbprl) was obtained by reverse transcription-polymerase chain reaction (rt/pcr) from pituitary rna with degenerate primers designed on the basis of the cdnas of the two prls (tprl188 and tprl177) from the tilapia, oreochromis niloticus. the sbprl cdna encodes a preprotein of 212 amino acids composed of a putative signal peptide of 24 residues and a mature protein of 188 amino acids that is the homologue of tiprl188. the cdna coding for ... | 1994 | 7804137 |
| immersion in bovine insulin stimulates growth of tilapia. | the objective of this study was to investigate the effects of bovine insulin on growth responses in tilapia. juvenile hybrid male tilapia (oreochromis niloticus x o aurea; n = 135) were subjected to 1 of 3 treatments. each treatment was subdivided into 3 replicates of 15 fish each. the fish were immersed into 1 of 2 doses (10 and 100 micrograms/100 ml water) of insulin or no hormone for 15 min per week for 8 weeks. body weight, growth and feed conversion efficiency were significantly higher as a ... | 1995 | 7873048 |
| physical biochemical properties of igm from a teleost fish. | teleost fish are able to produce igm class antibody, as are other vertebrates. when the teleost fish oreochromis niloticus was immunized with bovine serum albumin (bsa), it produced antibody to bsa with an average avidity of 7.4 x 10(8)/m. thus, dissociation of antigen-antibody complexes only occurred at conditions of < ph 2.5, > ph 11, > 4m nai or > 4m urea, demonstrating high stability of the complex. western blot analyses further showed the high specificity of the antibody to bsa. in contrast ... | 1994 | 7875748 |
| effect of rice husbandry on mosquito breeding at mwea rice irrigation scheme with reference to biocontrol strategies. | a study was carried out at mwea rice irrigation scheme, kenya, to assess the impact of rice husbandry on mosquito breeding and identify indigenous biocontrol agents with potential for controlling mosquito breeding in the scheme. the study established a close relationship between the schedule of the farming practices (particularly the flooding phase) and mosquito breeding. two groups of agents, entomopathogenic bacteria (bacillus thuringiensis var. israelensis) and larvivorous fish, were identifi ... | 1993 | 8096871 |
| evidence that two tilapia (oreochromis niloticus) prolactins have different osmoregulatory functions during adaptation to a hyperosmotic environment. | two forms of prolactin (tiprli and tiprlii), with only 69% sequence identity, have been previously described in the cichlid fish tilapia (oreochromis species). in the present study we have attempted to investigate the biological activity of these two prolactin forms during adaptation to a hyperosmotic environment. for this purpose, we have developed two highly sensitive (sensitivity: 0.05 ng/ml) and specific (cross-reactivity < 0.04%) radioimmunoassays for tiprli and tiprlii, using recombinant h ... | 1994 | 8185810 |
| effects of acclimation to hypertonic environment on plasma and pituitary levels of two prolactins and growth hormone in two species of tilapia, oreochromis mossambicus and oreochromis niloticus. | specific radioimmunoassays (rias) for the pair of tilapia prolactins (tprls) and growth hormone (tgh) were developed using antisera raised in rabbits. anti-tprl177 did not cross-react with tprl188 and tgh. anti-tprl188 did not cross-react with tprl177 and showed slight cross-reaction (3.1%) with tgh. anti-tgh showed negligible cross-reactions with tprl177 (0.4%) and tprl188 (1.6%). pituitary homogenates and plasma from oreochromis niloticus exhibited displacement curves parallel to the standards ... | 1993 | 8428646 |
| different thyroid hormone-deiodinating enzymes in tilapia (oreochromis niloticus) liver and kidney. | enzymes catalyzing the outer ring deiodination (ord) of iodothyronines are important for the regulation of thyroid hormone bioactivity. we have studied ord of thyroxine (t4) and 3,3',5'-triiodothyronine (rt3) in liver and kidney microsomes of fish, i.e. tilapia (oreochromis niloticus). tilapia kidney contains an enzyme which resembles the mammalian selenoenzyme type i iodothyronine deiodinase (id-i) with respect to substrate preference (rt3 > t4) and high (approximately microm) km values, but is ... | 1993 | 8477843 |
| comparative studies on the effects of herbicide atrazine on freshwater fish oreochromis niloticus and chrysichthyes auratus at assiut, egypt. | | 1996 | 8672079 |
| consequences of food restriction on short-term growth variation and on plasma circulating hormones in oreochromis niloticus in relation to sex. | in tilapia, there is a sex-related growth difference between males and females. this study tried to detect any correlation between the somatic growth and the plasma endocrine status. for this, individually marked (floytags) male and female tilapia (bw 82 +/- 10 g) were either starved or fed on different daily food rations (1, 2, or 3% of the biomass) during 15 days. we have found that specific growth rates (sgr) were positively and significantly related to feeding levels. growth hormone (gh) pla ... | 1996 | 8812362 |
| production of recombinant insulin-like growth factor-ii in the development of a radioimmunoassay in rainbow trout (oncorhynchus mykiss). | rainbow trout (oncorhynchus mykiss) insulin-like growth factor-ii (igf-ii) cdna was amplified by reverse transcription-polymerase chain reaction and cloned into an expression vector (parhs3) for production by escherichia coli. recombinant rainbow trout igf-ii (rtigf-ii) was recovered from bacterial inclusion bodies, solubilized, and purified by gel filtration chromatography under reducing conditions. after refolding of the peptide by dialysis at basic ph, we obtained a final yield of 820 microgr ... | 1996 | 8930606 |
| toxicity of crude extracellular products of aeromonas hydrophila in tilapia, tilapia nilotica. | extracellular products (ecp) secreted from aeromonas hydrophila with haemolytic and proteolytic activity were studied with respect to temperature and time of incubation as well as the lethal toxicity on tilapia, tilapia nilotica. the highest production of the haemolysin product was achieved when aer. hydrophila was grown at 35 degrees c for 30 h. tilapia erythrocyte was found to be more susceptible than sheep erythrocyte for determining the haemolytic activity. the haemolytic activity against ti ... | 1997 | 9351277 |
| characterization of a propylthiouracil-insensitive type i iodothyronine deiodinase. | mammalian type i iodothyronine deiodinase (d1) activates and inactivates thyroid hormone by outer ring deiodination (ord) and inner ring deiodination (ird), respectively, and is potently inhibited by propylthiouracil (ptu). here we describe the cloning and characterization of a complementary dna encoding a ptu-insensitive d1 from teleost fish (oreochromis niloticus, tilapia). this complementary dna codes for a protein of 248 amino acids, including a putative selenocysteine (sec) residue, encoded ... | 1997 | 9389495 |
| evidence that gonadotropin-releasing hormone (gnrh) functions as a prolactin-releasing factor in a teleost fish (oreochromis mossambicus) and primary structures for three native gnrh molecules. | three forms of gonadotropin-releasing hormone (gnrh) are isolated and identified here by chemical sequence analysis for one species of tilapia, oreochromis niloticus, and by hplc elution position for a second species of tilapia, o. mossambicus. of the three gnrh forms in o. mossambicus, chicken gnrh-ii (cgnrh-ii) and sea bream gnrh (sbgnrh) are present in greater abundance in the brain and pituitary than salmon gnrh (sgnrh). these three native forms of gnrh are shown to stimulate the release of ... | 1997 | 9390014 |
| effects of edifenphos and glyphosate on the immune response and protein biosynthesis of bolti fish (tilapia nilotica). | the effects of 1/1000 field recommended concentration of the organophosphorus compounds; edifenphos and glyphosate on the immune response and protein contents were investigated after different time intervals. the cell mediated immune response assessed by proliferative response of splenocytes to mitogens; phytohemagglutinin (pha) and concanavalin a (con a) for t cell and lipopolysaccharide (lps) for b cell decreased significantly in tems of the level of stimulation index in the treated fish and r ... | 1998 | 9536512 |
| molecular cytogenetic analysis of heterochromatin in the chromosomes of tilapia, oreochromis niloticus (teleostei: cichlidae). | the structure of the heterochromatic bands in mitotic chromosomes of the important tropical aquaculture species of tilapia, oreochromis niloticus, was investigated by the combination of the c-banding technique, chromosomal digestion with two restriction endonucleases and fluorescence in situ hybridization (fish) of two satellite dnas (sata and satb). the tilapia chromosomes presented heterochromatic bands in the centromeres and in the short arms of almost all chromosomes that were differentially ... | 1998 | 9609664 |
| dietary secondary amines and liver hepatoma in port harcourt, nigeria. | dietary secondary amines of some nigerian foodstuffs were analyzed by soxhlet extraction, using petroleum ether (b.p. 60-80 degrees c); followed by thin layer chromatography developed in a solvent system; n-butanol: 95% ethanol: water (4:2:1) for the qualitative test. each uv fluorescent band in the test chromatogram was scraped and eluted with distilled water, filtered and assayed for secondary amine content for the quantitative test. quantitative estimations were by the colorimetric methods. t ... | 1997 | 9629865 |
| testosterone differentially regulates expression of gnrh messenger rnas in the terminal nerve, preoptic and midbrain of male tilapia. | the purpose of the present study was to examine the regulation of three molecular variants of gonadotropin-releasing hormone (gnrh)-encoding mrnas by testosterone in the male tilapia oreochromis niloticus. tilapias castrated for two weeks were injected intraperitoneally with sesame oil or 5 microgram/g testosterone for 7 days. in situ hybridization histochemistry was performed using 35s-labelled 30-mer antisense oligonucleotide probes complementary to exon two (bases 1-30) of salmon-, seabream-, ... | 1998 | 9748480 |
| a novel stage-specific antigen is expressed only in early stages of spermatogonia in japanese eel, anguilla japonica testis. | we produced an antibody that recognized only early stages of spermatogonia in japanese eel testis. this antibody (anti-spermatogonia-specific antigen-1, anti-sgsa-1) recognized a band of about 38 kda in western blot analysis of extracts from eel testis. this antigen was observed by immunohistochemistry only in type-a and early type-b spermatogonia and could not be seen in the late type-b spermatogonia, which appeared after the initiation of spermatogenesis by a single injection of human chorioni ... | 1998 | 9820193 |
| quantitative in situ hybridization of three gonadotropin-releasing hormone-encoding mrnas in castrated and progesterone-treated male tilapia. | we investigated the effects of castration and progesterone administration on the three gonadotropin-releasing hormone (gnrh)-encoding mrnas in sexually mature male tilapia oreochromis niloticus. in situ hybridization histochemistry was performed using 35s-labeled antisense oligonucleotide probes complementary to salmon-, seabream-, and chicken ii-gnrh cdnas to quantify cellular gnrh mrna expression in the terminal nerve ganglia (nucleus olfactoretinalis), preoptic area, and midbrain tegmentum of ... | 1998 | 9843646 |
| expression of a novel piscine growth hormone gene results in growth enhancement in transgenic tilapia (oreochromis niloticus). | several lines of transgenic g1 and g2 tilapia fish (oreochromis niloticus) have been produced following egg injection with gene constructs carrying growth hormone coding sequences of fish origin. using a construct in which an ocean pout antifreeze promoter drives a chinook salmon growth hormone gene, dramatic growth enhancement has been demonstrated, in which the mean weight of the 7 month old g2 transgenic fish is more than three fold that of their non transgenic siblings. somewhat surprisingly ... | 1998 | 9859224 |
| effects of dieldrin on life stages of the african catfish, clarias gariepinus (burchell). | early life stages of clarias gariepinus were found to be less sensitive to acute dieldrin toxicity than were those of nile tilapia, oreochromis niloticus; 96-h lc50 values for 37-day-old fry were 11. 7 and 4.95 microg liter-1, respectively. the growth of c. gariepinus fry was unaffected by 30 days of exposure to 2.4 microg liter-1 dieldrin under static conditions with water renewal every 96 h, whereas growth of o. niloticus fry was significantly reduced. adult c. gariepinus exposed to dieldrin f ... | 1999 | 9931234 |
| effect of pesticide water pollution on some haematological, biochemical and immunological parameters in tilapia nilotica fish. | nine groups of tilapia nilotica fish each consisting of 50 fish were used to assess the effect of pesticides on the haematological, biochemical and immunological parameters in fish. four groups were injected with 0.05 ml of staphylococcus aureus antigen plus complete freund's adjuvant, the first group (g1) was exposed to lindane treatment, the second (g2) was exposed to dialdrin, the third (g3) was exposed to diazinon and the forth group (g4) was exposed to malathion. four other groups were not ... | 1999 | 10085581 |
| immunocytochemical characterization of the pancreatic islet cells of the nile tilapia (oreochromis niloticus). | the cellular composition and topography of the pancreatic islet of oreochromis niloticus, now known to be a donor source for islet xenotransplantation studies, were characterized. whole tilapia islets were harvested using an enzymatic method and then further digested into single-cell preparations. cell cytospin preparations of islet cells and paraffin sections of whole islets were stained using antisera against tilapia insulin, human glucagon, salmon somatostatin-25 (sst-25), human somatostatin- ... | 1999 | 10094858 |
| distribution and seasonal variations in levels of three native gnrhs in the brain and pituitary of perciform fish. | specific and sensitive radioimmunoassays (rias) were newly developed for two types of gonadotropin-releasing hormone (gnrh), namely, seabream (sb) gnrh and chicken (c) gnrh-ii. we employed these two rias together with a previously reported ria for salmon (s) gnrh to study the presence and regional distribution of these three gnrhs in the brains and pituitaries of four perciform fishes (red seabream, pagrus major; black seabream, acanthopagrus schlegeli; striped knifejaw, oplegnathus fasciatus; a ... | 1999 | 10201813 |
| induction of hsp70 by the herbicide oxyfluorfen (goal) in the egyptian nile fish, oreochromis niloticus. | this paper deals with the expression of the biomarker hsp70 in the liver and kidney of the freshwater fish oreochromis niloticus following exposure to the herbicide oxyfluorfen (goal). fishes were exposed to three concentrations, the 96-h lc50 (3 mg/l), the 96-h (1/2)lc50 (1.5 mg/l), and the 96-h (1/4)lc50 (0.75 mg/l) of oxyfluorfen for 6, 15, and 24 days, respectively, and samples were taken at three different time periods for each concentration. the livers responded to the herbicide by an indu ... | 1999 | 10341045 |
| cloning and characterization of type iii iodothyronine deiodinase from the fish oreochromis niloticus. | type iii iodothyronine deiodinase (d3) catalyzes the inner ring deiodination (ird) of t4 and t3 to the inactive metabolites rt3 and 3,3'-diiodothyronine (3,3'-t2), respectively. here we describe the cloning and characterization of complementary dna (cdna) coding for d3 in fish (oreochromis niloticus, tilapia). this cdna contains 1478 nucleotides and codes for a protein of 267 amino acids, including a putative selenocysteine (sec) residue, encoded by a tga triplet, at position 131. the deduced am ... | 1999 | 10433225 |
| degranulation of eosinophilic granular cells with possible involvement in neutrophil migration to site of inflammation in tilapia. | observations were made on stretched preparations from the swim bladder and peritoneum obtained from tilapia (oreochromis niloticus) after injection of formalin-killed escherichia coli, proteose peptone, compound 48/80 or hbss into the swim bladder. the eosinophilic granular cells (egcs) in the swim bladder degranulated rapidly after inoculation. however, the peritoneal egcs did not degranulate, indicating that degranulation occurs only at the injected site. there was also a correlation between t ... | 1999 | 10512456 |
| tilapia (oreochromis niloticus) and rodents exhibit similar patterns of inhibited antibody production following exposure to immunotoxic chemicals. | the hemolytic plaque forming cell assay (pfc), a measure of ability to produce specific antibodies following challenge with antigen, is a powerful predictor of immunosuppression in chemical-exposed rodents. the efficacy of this assay for predicting humoral immunosuppression in non-rodent species remains unknown. in the present report, tilapia (oreochromis niloticus) were exposed to 9 chemical agents known to inhibit antibody production in mice (benzo[a]pyrene, 7,12-dimethylbenzanthracene, 2,3,7, ... | 1999 | 10592942 |
| effect of egg deprivation on sex steroids, gonadotropin, prolactin, and growth hormone profiles during the reproductive cycle of the mouthbrooding cichlid fish oreochromis niloticus. | various hormones were analyzed during the course of a reproductive cycle in the cichlid fish oreochromis niloticus: plasma levels of the gonadal steroids 17beta-estradiol (e2), testosterone (t), 17, 20beta-oh progesterone (17,20beta-p), gonadotropin (tagth), and plasma and pituitary concentrations of prolactin (tiprl(i) and tiprl(ii)) and growth hormone (tigh). two categories of fish were sampled and sacrificed on days 1 and 3 postspawning and at 3-day intervals thereafter: typical incubating fe ... | 2000 | 10620423 |
| a line2 repetitive dna sequence from the cichlid fish, oreochromis niloticus: sequence analysis and chromosomal distribution. | we report the cloning and characterization of a long interspersed nucleotide element (line) from a cichlid fish, oreochromis niloticus, and show the distribution of this element, called ciline2 for cichlid line2, in the chromosomes of this species. the identification of an open reading frame in ciline2 with amino acid sequence similarity to reverse transcriptases encoded by line-like elements in caenorhabditis elegans, platemys spixii, schistosoma mansoni, gallus gallus (cri), drosophila melanog ... | 1999 | 10654084 |
| comparative severity of experimentally induced mycobacteriosis in striped bass morone saxatilis and hybrid tilapia oreochromis spp. | twenty striped bass morone saxatilis and 20 hybrid tilapia oreochromis niloticus x o. mossambicus x o. aureus each received a single intramuscular injection of 1.6 x 10(6) colony forming units per gram body weight of mycobacterium marinum. striped bass manifested significantly greater clinical and microscopic disease compared to tilapia. whereas all the striped bass had died or were clinically ill by day 8 post-infection, there was no apparent disruption of normal behaviour, physical appearance, ... | 1999 | 10686670 |
| ultrastructure of sperm and spermatogenesis of cichlidogyrus thurstonae (platyhelminthes, monogenea, monopisthocotylea). | the present work is the first ultrastructural description of mature spermatozoon of the monogenetic trematode cichlidogyrus thurstonae recovered from the gills of the nile fish oreochromis niloticus. the mature spermatozoon of c. thurstonae is long and filiform with a nucleus, mitochondrion and a single axoneme, pressed tightly together for most of their length. as most other platyhelminthes, a solid central unit in the complex central element of the sperm axoneme is present. there are no periph ... | 2000 | 10786032 |
| thyroid hormone and estrogen regulate brain region-specific messenger ribonucleic acids encoding three gonadotropin-releasing hormone genes in sexually immature male fish, oreochromis niloticus. | the present study was undertaken to determine whether t3, estrogen, and 11-ketotestosterone could alter a specific population of gnrh-containing neurons, as indicated by a change in messenger rna (mrna) levels in sexually immature male tilapia, oreochromis niloticus. two weeks after castration, fish were assigned to four treatment groups. one group served as the control (sesame oil); a single ip injection of (t3; 5 microg/g), estradiol benzoate (eb; 5 microg/g), or 11-ketotestosterone (kt; 5 mic ... | 2000 | 10803569 |
| growth of nile tilapia oreochromis niloticus fed with different levels of alcohol yeast. | two hundred and forty 45-day-old fingerlings of nile tilapia (oreochromis niloticus), sexually reverted with an initial average weight of 1.25 +/- 0.14 g, distributed in a totally casualized delineation, during 330 days. the effect of the substitution of 10%, 20% and 30% of the ration by distillery yeast (saccharomiyces cerevisae) in balanced experimental rations on the development in the breeding of tilapias did not show a harmful effect up to the maximum tested level of 30%, showing that the c ... | 2000 | 10838930 |
| immune responses of nile tilapia (oreochromis niloticus l.) clones: i. non-specific responses. | the importance of genetic variation in the non-specific immune responses of nile tilapia (oreochromis niloticus l.) clones was investigated. fully inbred clones (ic) of nile tilapia, produced using gynogenesis and sex reversal, and crosses between these lines (outbred clones) were used in this study. non-specific immune responses were compared between the ics, including serum lysozyme activity and phagocytosis, and significant differences were observed between the different groups. their natural ... | 2001 | 10980318 |
| human exposure to mercury due to small scale gold mining in northern tanzania. | in northern tanzania large numbers of small scale miners use mercury in the gold extraction process causing contamination of the environment and risks to human health. human exposure to hg was assessed in populations in and around small scale gold mining camps by means of human hair and urine surveys. we also determined hg concentration in fish in aquatic bodies close to these camps. urinary hg testing in three communities showed that 36% of the gold miners working with amalgam exceeded the who ... | 2000 | 11032134 |
| the liver monooxygenase system of brazilian freshwater fish. | content of cytochromes b5 and p-450, and activities of nadph-cytochrome c (p-450) reductase (ncr) and 7-ethoxyresorufin o-deethylase (erod) were measured in liver microsomes prepared from two south american endemic fish, brycon cephalus and colossoma macropomum, from tilapia, oreochromis niloticus, and from swiss mice, mus musculus, which served as a control. strong hemoglobin binding to fish liver microsomal membranes (flm) altered visible spectra of microsomal cytochromes. consequently, specia ... | 2000 | 11048662 |
| [parasitologic survey of schistosomiasis due to schistosoma mansoni in katana, democratic republic of congo]. | it is now widely recognized that development of irrigation projects in endemic areas for schistosomiasis invariably leads to a recrudescence of the disease by increasing the habitat of the intermediate snail host of schistosoma mansoni. this fatality was again demonstrated by experience in the katana region of the democratic republic of congo where development of 43 fresh water reservoirs for raising tilapia nilotica led to multiplication of biomphalaria pfeifferi. a parasitological study was co ... | 2000 | 11100444 |
| colocalization of neuronal no synthase with urotensins i and ii in the caudal neurosecretory neurons and the urophysis of the teleost oreochromis niloticus: a gold immunoelectron microscopic study. | the intracellular distribution of neuronal nitric oxide synthase (nnos) was studied in the caudal neurosecretory system of a teleost, oreochromis niloticus (cichlids), by means of post-embedding immunogold labeling with a polyclonal antibody directed against nnos of human origin. ultrastructural examination demonstrated that neuronal nos-like molecules are distributed within the dahlgren cell perikarya, the neurosecretory axons, and the urophysial axon terminals. in the neurosecretory somata, go ... | 2000 | 11111135 |
| jule from the fish xiphophorus is the first complete vertebrate ty3/gypsy retrotransposon from the mag family. | jule is the second complete long-terminal-repeat (ltr) ty3/gypsy retrotransposon identified to date in vertebrates. jule, first isolated from the poeciliid fish xiphophorus maculatus, is 4.8 kb in length, is flanked by two 202-bp ltrs, and encodes gag (structural core protein) and pol (protease, reverse transcriptase, rnase h, and integrase, in that order) but no envelope. there are three to four copies of jule per haploid genome in x. maculatus. two of them are located in a subtelomeric region ... | 2001 | 11158369 |
| physiological and molecular characterization of urea transport by the gills of the lake magadi tilapia (alcolapia grahami). | the lake magadi tilapia (alcolapia grahami) is an unusual fish, excreting all its nitrogenous waste as urea because of its highly alkaline and buffered aquatic habitat. here, using both physiological and molecular studies, we describe the mechanism of branchial urea excretion in this species. in vivo, repeated short-interval sampling revealed that urea excretion is continuous. the computed urea permeability of a. grahami gill is 4.74x10(-)(5)+/-0.38x10(-)(5 )cm s(-)(1) (mean +/- s.e.m., n=11), s ... | 2001 | 11171302 |
| risk assessment of etofenprox (vectron) on non-target aquatic fauna compared with other pesticides used as simulium larvicide in a tropical environment. | within the rotational scheme developed by the programme to fight the resistance of simulium damnosum to chemical larvicides, there was an operational gap at discharges between 5 and 70 m3 s(-1) for the treatment of rivers where resistance to organophosphates was present. the use of permethrin and carbosulfan was precluded because of risk of environmental impact and, bacillus thuringiensis ser. h-14 treatments were not envisageable due to cost and logistics constraints. among the possible complem ... | 2001 | 11272920 |
| cadmium and lead levels in fish (tilapia nilotica) tissues as biological indicator for lake water pollution. | cadmium and lead were determined in different tissues (muscle, gill, stomach, intestine. liver, vertebral column and scales) of tilapia nilotica from the high dam lake, aswan (egypt) to assess the lake water pollution with those toxic metals. fish samples were chosen from different ages and weights to be analyzed along with samples of the aquatic plant (najas armeta), sediment and lake water. the results showed that cadmium and lead concentrations were higher in fish scales and vertebral column ... | 2001 | 11336413 |
| non-ltr retrotransposons encoding a restriction enzyme-like endonuclease in vertebrates. | all autonomous non-long terminal repeat (non-ltr) retrotransposons reported to date in vertebrates encode an apurinic/apyrimidinic endonuclease-like enzyme necessary for target sequence cleavage and subsequent target-primed reverse transcription. we describe here vertebrate non-ltr retrotransposons encoding another type of endonuclease more related to type iis restriction enzymes. such retrotransposons have been detected until now only in trypanosomes, nematodes, and arthropods. the retrotranspo ... | 2001 | 11343131 |
| regulation of gonadotropin subunit genes in tilapia. | a steroidogenic tilapia gonadotropin (tagth=lh) was purified from pituitaries of hybrid tilapia (oreochromis niloticus x o. aureus) and a homologous ria was established. this ria enabled the study of the endocrine regulation of gth release, the transduction pathways involved in its secretion and its profile during the spawning cycle. discrepancies between steroid and tagth peaks during the cycle led to the conclusion that an additional gonadotropin similar to salmonid fsh operates early in the c ... | 2001 | 11399484 |
| environmental monitoring using acetylcholinesterase inhibition in vitro. a case study in two mexican lagoons. | cholinesterase inhibition is considered a specific biomarker of exposure and effect for organophosphorous pesticides. its use for monitoring has been hindered, particularly in tropical countries where organophosphates are widely used for malaria and dengue control, because of the frequent lack of suitable controls. an in vitro technique is proposed as a biochemical method for monitoring pollutant mixtures in sediment toxicity tests. brain homogenate from the fish oreochromis niloticus is used as ... | 2000 | 11460718 |
| toxicity of sediments from bahía de chetumal, méxico, as assessed by hepatic erod induction and histology in nile tilapia oreochromis niloticus. | the effect of environmental pollutants present in sediments obtained from bahía de chetumal, a bay on the border between mexico and belize, was studied in nile tilapia (oreochromis niloticus) intraperitoneally injected with sediment extracts from six different sites of the bay. sediment samples used for the study contained a variety of organic chemicals such as organochlorine pesticides, polychlorinated biphenyls (pcbs) and polynuclear aromatic hydrocarbons (pahs). total cytochrome p-450 and ero ... | 2000 | 11460723 |
| cone opsin genes of african cichlid fishes: tuning spectral sensitivity by differential gene expression. | spectral tuning of visual pigments is typically accomplished through changes in opsin amino acid sequence. within a given opsin class, changes at a few key sites control wavelength specificity. to investigate known differences in the visual pigment spectral sensitivity of the lake malawi cichlids, metriaclima zebra (368, 488, and 533 nm) and dimidiochromis compressiceps (447, 536, and 569 nm), we sequenced cone opsin genes from these species as well as labeotropheus fuelleborni and oreochromis n ... | 2001 | 11470845 |
| monitoring of environmental heavy metals in fish from nasser lake. | lake ecosystems are, in particular, vulnerable to heavy metal pollution. tilapia nilotica is one of the aquatic organisms affected by heavy metals. therefore, heavy metals co, cr, cu, fe, mn, ni, sr and zn were determined in different tissues of t. nilotica (ages 1, 1.5, 2, 2.5 and 3 years), which include the muscle, gill, stomach, intestine, liver, vertebral column and scales, to assess the fish pollution with heavy metals. in addition, the study was extended to determine these elements in the ... | 2001 | 11488387 |
| effect of macrophages and serum of fish susceptible or resistant to epizootic ulcerative syndrome (eus) on the eus pathogen, aphanomyces invadans. | epizootic ulcerative syndrome (eus) is one of the most destructive diseases of fresh and brackish water farmed and wild fish in the asia-pacific region. the in vitro germination and growth of the propagules of the eus pathogen, aphanomyces invadans (= a. piscicida), were assessed in the presence of the head-kidney macrophages, serum, and serum heated to inactivate complement proteins, of three eus-susceptible and one resistant fish species. the susceptible species were: striped snakehead (channa ... | 2001 | 11592585 |
| growth of broad-nosed caiman, caiman latirostris (daudin, 1802) hatchlings, fed with diets of animal origin. | the study was carried out to evaluate the growth rate of broad-nosed caiman, caiman latirostris hatchlings, fed on four animal protein diets: (a) dead poultry from a poultry farm; (b) dead piglet from nursery and farrowing house in a swine farm; (c) whole tilapia (tilapia rendalli e oreochromis niloticus); and (d) a balanced mixture of a, b, and c sources. sixteen seven-month old caimans, average weight of 208 g and, 38 cm of total length (tl) were distributed in four treatments. four groups of ... | 2002 | 11706569 |
| identification, localization and morphology of apud cells in gastroenteropancreatic system of stomach-containing teleosts. | aim:to identify the type localization and morphology of apud endocrine cells in the gastroenteropancreatic (gep) system of stomach-containing teleosts, and study apud endocrine system in the stomach, intestine and pancreas of fish species.methods:two kinds of immunocytochemical (icc) techniques of the streptavidin biotin-peroxidase complex (sabc) and streptavidin-peroxidase (s-p) method were used. the identification, localization and morphology of apud endocrine cells scattered in the mucosa of ... | 2000 | 11819706 |
| the goitrogen 6-n-propyl-2-thiouracil (ptu) given during testis development increases sertoli and germ cell numbers per cyst in fish: the tilapia (oreochromis niloticus) model. | the main objectives of the present study were to investigate the effects of 6-n-propyl-2-thiouracil (ptu) on sertoli cell proliferation, germ cell number, and testis size in nile tilapias (oreochromis niloticus). in this regard, young fish (approximately 1 g bw and approximately 3.5 cm total in length) were treated for a period of 40 d with different concentrations (100 and 150 ppm) of ptu. the animals were killed and analyzed on d 1, 30, 40, 98, and 208 after the beginning of the treatment. on ... | 2002 | 11861520 |
| effect of pyrene on hepatic cytochrome p450 1a (cyp1a) expression in nile tilapia (oreochromis niloticus). | the effect of pyrene on the regulation of the gene expression of cytochrome p4501a ( cyp1a) was studied in tilapia (oreochromis niloticus), a tropical fish of great ecological and economical importance. to evaluate cyp1a mrna, tilapia cyp1a cdna was cloned, sequenced, and compared with those cyp1a reported sequences in the genebank dna database. the top seven matches corresponded to cyp1a from other teleosts. hepatic cyp1a mrna levels showed a significant increase at day 1 after pyrene injection ... | 2002 | 11994790 |
| haplorchis infections in intermediate hosts from a clonorchiasis endemic area in meinung, taiwan, republic of china. | snails and freshwater fish were examined from four ponds in the meinung township in which clonorchis sinensis was known to be endemic 18 years ago. no metacercariae were found in 478 tilapia nilotica, whereas of 451 ctenopharyngodon idellus examined, 16.2%, 3.3% and 0.9% were found to be infected with haplorchis pumilio, h. taichui and clonorchis sinensis, respectively. in addition, there were some unidentified metacercariae in 12.0% of ctenopharyngodon idellus examined. overall, no positive cor ... | 2002 | 12015833 |
| toxicity of lapachol and isolapachol and their potassium salts against biomphalaria glabrata, schistosoma mansoni cercariae, artemia salina and tilapia nilotica. | the toxicity of soluble derivatives (potassium salt) of lapachol and isolapachol in different stages of the life cycle of schistosoma mansoni is evaluated. the potassium salts of isolapachol and lapachol showed significant molluscicidal activity against the adult snail (lc90<7 ppm) and snail egg masses (lc90<3 ppm). cercaricidal assays revealed strong activities for both compounds. lethality assays against brine shrimp eggs (artemia salina leach) indicated very high toxicity for the potassium sa ... | 2002 | 12062792 |
| piscinoodinium pillulare (schäperclaus, 1954) lom, 1981 (dinoflagellida) infection in cultivated freshwater fish from the northeast region of sao paulo state, brazil. parasitological and pathological aspects. | the aquaculture center of unesp, jaboticabal, sp, brazil, received fishes for diagnosis from fish farmers reporting fish crowding at pond edges and in water inlets. fifty-three out of 194 cases showed round to oval, immobile whitish structures, measuring up to 162 microm diameter, identified as the dinoflagellate piscinoodinium pillulare. in 34 diagnosed cases the parasites were present in the gills, in 2 on body surface, and 9 in both. thirty-one out of 53 were tambacu hybrids hosts; 7, piaract ... | 2002 | 12071320 |
| molecular cloning of dax1 and shp cdnas and their expression patterns in the nile tilapia, oreochromis niloticus. | piscine dax1 and shp cdnas with an open reading frame encoding 296 and 258 amino acid residues, respectively, as well as shp partial gene fragment, were cloned from nile tilapia. phylogenetic analyses of dax1s, shps, and homologous est fragments indicate that dax1 and shp are conserved in gene structure and are present throughout vertebrates. a single band of approximately 1.4kb for dax1 and of approximately 1.2kb for shp was detected in the northern blot analysis. tissue distribution analysis b ... | 2002 | 12270141 |
| high vitamin a content in some small indigenous fish species in bangladesh: perspectives for food-based strategies to reduce vitamin a deficiency. | recognising the importance of fish in the bangladeshi diet, the objective of the present study was to screen commonly consumed fish species for vitamin a content to evaluate the potential of fish as a vitamin a source in food-based strategies to combat vitamin a deficiency. samples of 26 commonly consumed fish species and one crustacean were collected in kishoreganj and mymensingh, bangladesh. to obtain edible parts, the fish were cleaned by bangladeshi women according to traditional practices. ... | 2002 | 12396468 |
| cultured gill epithelia from freshwater tilapia (oreochromis niloticus): effect of cortisol and homologous serum supplements from stressed and unstressed fish. | procedures for the preparation and culture of branchial epithelia from dispersed gill cells of freshwater tilapia (oreochromis niloticus) are described. epithelia were cultured on permeable supports (terephthalate membranes, "filters") and bathed on both the apical and basolateral side with isotonic media containing 6% fetal bovine serum (fbs). when the apical medium was replaced with freshwater (pseudo in vivo asymmetrical culture conditions), transepithelial resistance (ter) increased markedly ... | 2002 | 12422270 |
| population dynamics of piscicola geometra (hirudinea: rhynchobdellida) on oreochromis niloticus (cichlidae) cultured in a rainforest fish pond, south eastern nigeria. | the distribution, abundance and intensity of the annelid worm, piscicola geometra(leeches) infecting oreochromis niloticus cultured in a rainforest fish pond, south eastern nigeria was studied over a 12 months period. three hundred fish were examined of which 48.3% were infected. infection occurred throughout the year, with a peak in february. female fish had a significantly higher intensity of infection(p < 0.05) than males. there was a clear seasonal periodicity in the degree of infection and ... | 2002 | 12491729 |
| estimation of microcystins in the freshwater fish oreochromis niloticus in an egyptian fish farm containing a microcystis bloom. | microcystins (mcysts) that accumulated in different organs of the freshwater fish oreochromis niloticus, collected from a fish farm in egypt containing heavy blooms of microcystis aeruginosa, were investigated using an enzyme-linked immunosorbent assay (elisa). the distribution of mcysts in the organs varied significantly. the highest mcyst level was recorded in the guts (821 ng/g fresh weight), followed by the livers (531.8 ng/g) and kidneys (400 ng/g). smaller amounts of mcyst were detected in ... | 2003 | 12635102 |
| teleost fish spermatozoa contain a cytosolic protein factor that induces calcium release in sea urchin egg homogenates and triggers calcium oscillations when injected into mouse oocytes. | established studies in a variety of organisms including amphibians, fish, ascidians, nemerteans, echinoderms, mammals, and even a species of flowering plant, clearly demonstrate that an increase in intracellular egg calcium is crucial to the process of egg activation at fertilization. in echinoderms, egg activation appears to involve an egg phospholipase c gamma (plcgamma). however, numerous studies in mammalian species suggest that calcium is released from internal egg stores at fertilization b ... | 2003 | 12745073 |
| characterisation of aeromonas spp. isolated from frozen fish intended for human consumption in mexico. | a total of 82 strains of presumptive aeromonas spp. were identified biochemically and genetically (16s rdna-rflp). the strains were isolated from 250 samples of frozen fish (tilapia, oreochromis niloticus niloticus) purchased in local markets in mexico city. in the present study, we detected the presence of several genes encoding for putative virulence factors and phenotypic activities that may play an important role in bacterial infection. in addition, we studied the antimicrobial patterns of t ... | 2003 | 12781953 |
| genes encoding putative natural killer cell c-type lectin receptors in teleostean fishes. | mammalian natural killer (nk) cells are cytotoxic lymphocytes that express receptors specific for mhc class i molecules. the nk cell receptors belong to two structurally unrelated families, the killer cell ig-like receptors and the killer cell c-type lectin receptors. we describe a cdna clone derived from the bony (cichlid) fish paralabidochromis chilotes and show that it encodes a protein related to the cd94/nk cell group 2 (nkg2) subfamily of the killer cell c-type lectin receptors. the gene e ... | 2003 | 12802013 |
| fsh and lh-beta subunits in the preoptic nucleus: ontogenic expression in teleost. | in the present study we cloned, sequenced, and confirmed the presence of mrnas of gonadotropins (fsh-beta, lh-beta subunits) from the brain and pituitary of tilapia, oreochromis niloticus. further, we examined the spatio-temporal expression pattern of fsh-beta and lh-beta in the brain and pituitary of two species of teleost (tilapia, o. niloticus; sockeye salmon, oncorhynchus nerka), using in situ hybridization and immunological methods. the expression of fsh and lh immunoreactivity appeared sim ... | 2003 | 12849959 |
| expression of nitric oxide synthase in the preoptic-hypothalamo-hypophyseal system of the teleost oreochromis niloticus. | in the present study, we have analyzed the expression of nitric oxide synthase (nos) in the preoptic-hypothalamo-hypophyseal system of the teleost oreochromis niloticus. the assay for enzyme activity demonstrated that a constitutive nos activity is present both in soluble and particulate fractions of the homogenates of diencephalons. western blot analysis using an antibody against the n-terminus of human nnos revealed two bands both in the supernatant and in the pellet. one band co-migrates at a ... | 2003 | 12907859 |
| isolation, characterization and expression of 11beta-hydroxysteroid dehydrogenase type 2 cdnas from the testes of japanese eel (anguilla japonica) and nile tilapia (oreochromis niloticus). | the japanese eel (anguilla japonica) and nile tilapia (oreochromis niloticus) 11beta-hydroxysteroid dehydrogenase type 2 (11beta-hsd2) cdnas were isolated from their respective testes cdna libraries. the cdnas predict two peptides of 436 and 406 amino acid residues that share about 42% homology with mammalian 11beta-hsd type 2 proteins. analysis of the tissue distribution pattern by rt-pcr reveals that 11beta-hsd2 is expressed in a wide variety of tissues in tilapia, with higher expression in ki ... | 2003 | 14519098 |
| a novel cold-adapted imidase from fish oreochromis niloticus that catalyzes hydrolysis of maleimide. | in this paper we report the first comparative study of cold-adapted imidase (ec 3.5.2.2) from the fish (oreochromis niloticus) liver and its thermophilic counterparts taken from pig liver and escherichia coli (overexpressed recombinant hydantoinase from agrobacterium radiobacter nrrl b1). approximately 6000-fold purification and a 40% yield of fish imidase activity were obtained through ammonium sulfate precipitation, octyl, chelating, deae, and hydroxyapatite chromatography. this cold-adapted i ... | 2003 | 14637160 |
| evaluation of the carcinogenic effects of furazolidone and its metabolites in two fish species. | the major metabolite from the use of furazolidone (fzd) in mammals, birds and fish is 2,3-dihydro-3-cyanomethyl-2-hydroxy-5-nitro-1alpha, 2-di(2-oxo-oxazolidin-3-yl)iminomethyl-furo[2,3-beta]furan, also called 3-amine-2-oxazolidone (aoz). a minor metabolite was identified as n-(5-amine-2-furfuryliden)-3-amine-2-oxazolidone (foz). to assess the potential carcinogenicity of fzd and the metabolic mixture of aoz/foz, 11 mg fzd/kg feed/day was fed for 12 weeks to mollies (poecilia formosa), an orname ... | 2004 | 14647403 |
| the biology of oreochromis niloticus in a polluted canal. | in the present investigation, length-weight relationship, condition factor, age, growth, mortality, gonadosomatic index (gsi) and fecundity of tilapias (bolti in arabic): oreochromis niloticus, from shanawan drainage canal (sdc), al-minufiya province, egypt, were studied. this was carried out on 162 fish samples collected during the period from april 1992 to may 1993. oreochromis niloticus was found to attain sexual maturity early (8-9 cm), was more fecund (1,234-3,893) and has high mortality ra ... | 2003 | 14649423 |
| induced alkoxyresorufin-o-dealkylases in tilapias (oreochromis niloticus) from guandu river, rio de janeiro, brazil. | the activity of fish monooxygenases has been extensively used as a monitoring tool to detect contamination of water bodies by cytochrome p450-inducing agents. in this study we evaluated the activities of ethoxy- (erod), methoxy- (mrod) and pentoxy- (prod) resorufin-o-dealkylases in the liver of nile tilapias (oreochromis niloticus) collected at the guandu river, at a reference clean site (lake 1) and at two other sampling sites (lakes 2 and 3) in rio de janeiro state, brazil. alkoxyresorufin-o-d ... | 2004 | 14675840 |
| clustering of c-type lectin natural killer receptor-like loci in the bony fish oreochromis niloticus. | the genome of the cichlid (teleost) fish oreochromis niloticus contains a set of genes which encode group v c-type lectin proteins homologous to the mammalian nkg2/cd94 family of natural killer (nk) cell receptors. to determine the genomic organization of these killer cell-like receptor (klr) genes, an o. niloticus bac library was screened with a cdna probe derived previously from an expressed sequence tag of the related cichlid species paralabidochromis chilotes. four distinct klr-bearing bac c ... | 2004 | 14871289 |
| genetic characterization of four strains of nile tilapia (oreochromis niloticus l.) using microsatellite markers. | four domesticated strains of nile tilapia (oreochromis niloticus l.) were genetically characterized using 14 microsatellite markers and 64 animals per strain. two strains, chitralada (ait) and international development research centers (idrc) were obtained from the ait institute, bangkok, thailand. the gift strain (5th generation) came from nagri, thailand, and the gott strain was supplied by the university of göttingen, germany. the average numbers of alleles per marker were 5.0 (gott), 5.4 (ai ... | 2004 | 15025567 |
| ontogenic development of three gnrh systems in the brain of a pleuronectiform fish, barfin flounder. | a pleuronectiform fish, the barfin flounder verasper moseri, has three molecular forms of gonadotropin-releasing hormone (gnrh) in the brain, salmon gnrh (sgnrh), chicken gnrh-ii (cgnrh-ii) and seabream gnrh (sbgnrh). to elucidate the ontogenic origin of the neurons that produce these gnrh molecules, the development of three gnrh systems was examined by in situ hybridization and immunocytochemistry. neuronal somata that express sgnrh mrna were detected first in the vicinity of the olfactory epit ... | 2004 | 15056926 |
| effects of lead and cadmium interactions on the metal accumulation in tissue and organs of the nile tilapia (oreochromis niloticus). | | 2004 | 15058666 |