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Paiola M, Moreira C, Hétru J, Duflot A, Pinto PIS, Scapigliati G, Knigge T, Monsinjon T. Prepubertal gonad investment modulates thymus function: evidence in a teleost fish. J Exp Biol 2021; 224:238091. [PMID: 33789987 DOI: 10.1242/jeb.238576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Accepted: 01/20/2021] [Indexed: 12/12/2022]
Abstract
Thymus plasticity following gonadectomy or sex hormone replacement has long since exemplified sex hormone effects on the immune system in mammals and, to a lesser extent, in 'lower vertebrates', including amphibians and fish. Nevertheless, the underlying physiological significances as well as the ontogenetic establishment of this crosstalk remain largely unknown. Here, we used a teleost fish, the European sea bass, Dicentrarchus labrax, to investigate: (1) whether the regulation of thymus plasticity relies on resource trade-off with somatic growth and reproductive investment and (2) if the gonad-thymus interaction takes place during gonadal differentiation and development. Because gonadal development and, supposedly, thymus function in sea bass depend on environmental changes associated with the winter season, we evaluated thymus changes (foxn1 expression, and thymocyte and T cell content) in juvenile D. labrax raised for 1 year under either constant or fluctuating photoperiod and temperature. Importantly, in both conditions, intensive gonadal development following sex differentiation coincided with a halt of thymus growth, while somatic growth continued. To the best of our knowledge, this is the first study showing that gonadal development during prepuberty regulates thymus plasticity. This finding may provide an explanation for the initiation of the thymus involution related to ageing in mammals. Comparing fixed and variable environmental conditions, our work also demonstrates that the extent of the effects on the thymus, which are related to reproduction, depend on ecophysiological conditions, rather than being directly related to sexual maturity and sex hormone levels.
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Affiliation(s)
- Matthieu Paiola
- Normandy University, FR CNRS 3730 SCALE, UMR-I 02 INERIS-URCA-ULH Environmental Stress and Aquatic Biomonitoring (SEBIO), University of Le Havre Normandy, 76600 Le Havre, France
| | - Catarina Moreira
- Normandy University, FR CNRS 3730 SCALE, UMR-I 02 INERIS-URCA-ULH Environmental Stress and Aquatic Biomonitoring (SEBIO), University of Le Havre Normandy, 76600 Le Havre, France
| | - Julie Hétru
- Normandy University, FR CNRS 3730 SCALE, UMR-I 02 INERIS-URCA-ULH Environmental Stress and Aquatic Biomonitoring (SEBIO), University of Le Havre Normandy, 76600 Le Havre, France
| | - Aurélie Duflot
- Normandy University, FR CNRS 3730 SCALE, UMR-I 02 INERIS-URCA-ULH Environmental Stress and Aquatic Biomonitoring (SEBIO), University of Le Havre Normandy, 76600 Le Havre, France
| | - Patricia I S Pinto
- Laboratory of Comparative Endocrinology and Integrative Biology, CCMAR - Centre of Marine Sciences, University of Algarve, 8005-139 Faro, Portugal
| | - Giuseppe Scapigliati
- Department for Innovation in Biological, Agro-food and Forest Systems, Tuscia University, 01100 Viterbo, Italy
| | - Thomas Knigge
- Normandy University, FR CNRS 3730 SCALE, UMR-I 02 INERIS-URCA-ULH Environmental Stress and Aquatic Biomonitoring (SEBIO), University of Le Havre Normandy, 76600 Le Havre, France
| | - Tiphaine Monsinjon
- Normandy University, FR CNRS 3730 SCALE, UMR-I 02 INERIS-URCA-ULH Environmental Stress and Aquatic Biomonitoring (SEBIO), University of Le Havre Normandy, 76600 Le Havre, France
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Yilmaz O, Prat F, Ibáñez AJ, Köksoy S, Amano H, Sullivan CV. Multiple vitellogenins and product yolk proteins in European sea bass (Dicentrarchus labrax): Molecular characterization, quantification in plasma, liver and ovary, and maturational proteolysis. Comp Biochem Physiol B Biochem Mol Biol 2015; 194-195:71-86. [PMID: 26643259 DOI: 10.1016/j.cbpb.2015.11.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Revised: 11/03/2015] [Accepted: 11/26/2015] [Indexed: 11/30/2022]
Abstract
Three complete vitellogenin (Vtg) polypeptides of European sea bass (Dicentrarchus labrax), an acanthomorph teleost spawning pelagic eggs in seawater, were deduced from cDNA and identified as VtgAa, VtgAb and VtgC based on current Vtg nomenclature and phylogeny. Label free quantitative mass spectrometry verified the presence of the three sea bass Vtgs or their product yolk proteins (YPs) in liver, plasma and ovary of postvitellogenic females. As evidenced by normalized spectral counts, VtgAb-derived protein was 2- to 5-fold more abundant, depending on sample type, than for VtgAa, while VtgC-derived protein was less abundant, albeit only 3-fold lower than for VtgAb in the ovary. Western blotting with Vtg type-specific antisera raised against corresponding gray mullet (Mugil cephalus) lipovitellins (Lvs) detected all three types of sea bass Vtg in the blood plasma of gravid females and/or estrogenized males and showed that all three forms of sea bass Lv undergo limited partial degradation during oocyte maturation. The comparatively high levels of VtgC-derived YPs in fully-grown oocytes and the maturational proteolysis of all three types of Lv differ from what has been reported for other teleosts spawning pelagic eggs in seawater but are similar to recent findings for two species of North American Moronidae, the striped bass (Morone saxatilis) and white perch (Morone americana), which spawn pelagic and demersal eggs, respectively in fresh water. Together with the high Vtg sequence homologies and virtually identical structural features of each type of Vtg between species, these findings indicate that the moronid multiple Vtg systems do not substantially vary with reproductive environment.
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Affiliation(s)
- Ozlem Yilmaz
- Akdeniz University, Fisheries Faculty, Antalya, 07070, Turkey
| | - Francisco Prat
- Instituto de Ciencias Marinas de Andalucía, Consejo Superior de Investigaciones Científicas, Avda. República Saharaui 2, 11510 Puerto Real, Cádiz, Spain
| | - A Jose Ibáñez
- Instituto de Acuicultura de Torre de la Sal, Consejo Superior de Investigaciones Científicas, Torre de la Sal, s/n 12595, Ribera de Cabanes, Castellòn, Spain
| | - Sadi Köksoy
- Central Research and Immunology Laboratories, Akdeniz University, Faculty of Medicine, Antalya, 07070, Turkey
| | - Haruna Amano
- School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0373, Japan
| | - Craig V Sullivan
- Department of Biology, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, NC 27695-7617, USA.
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Yilmaz O, Prat F, Ibañez AJ, Amano H, Koksoy S, Sullivan CV. Estrogen-induced yolk precursors in European sea bass, Dicentrarchus labrax: Status and perspectives on multiplicity and functioning of vitellogenins. Gen Comp Endocrinol 2015; 221:16-22. [PMID: 25637672 DOI: 10.1016/j.ygcen.2015.01.018] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Revised: 12/30/2014] [Accepted: 01/10/2015] [Indexed: 01/22/2023]
Abstract
The estrogen-inducible egg yolk precursor, vitellogenin, of the European sea bass (Dicentrarchus labrax) has received considerable scientific attention by virtue of its central importance in determination of oocyte growth and egg quality in this important aquaculture species. However, the multiplicity of vitellogenins in the sea bass has only recently been examined. Recent cloning and homology analyses have revealed that the sea bass possesses the three forms of vitellogenin, VtgAa, VtgAb and VtgC, reported to occur in some other highly evolved teleosts. Progress has been made in assessing the relative abundance and special structural features of the three Vtgs and their likely roles in oocyte maturation and embryonic nutrition. This report discusses these findings in the context of our prior knowledge of vitellogenesis in this species and of the latest advances in our understanding of the evolution and function of multiple Vtgs in acanthomorph fishes.
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Affiliation(s)
- Ozlem Yilmaz
- Akdeniz University, Fisheries Faculty, Antalya 07070, Turkey; National Institute of Agrinomic Research, Campus de Beaulieu, 35000 Rennes Cedex, France(1).
| | - Francisco Prat
- Instituto de Acuicultura de Torre de la Sal (CSIC), 12595 Castellón, Spain; Instituto de Ciencias Marinas de Andalucía (CSIC), 11510 Cádiz, Spain(1)
| | - Antonio José Ibañez
- Instituto de Acuicultura de Torre de la Sal (CSIC), 12595 Castellón, Spain; Electron and Confocal Microscopy Service, University of Valencia, 46100 Valencia, Spain(1)
| | - Haruna Amano
- School of Marine Biosciences, Kitasato University, 1-15-1 Kitasato, Minami, Sagamihara, Kanagawa 252-0373, Japan
| | - Sadi Koksoy
- Faculty of Medicine, Akdeniz University, Antalya 07070, Turkey
| | - Craig V Sullivan
- Department of Biology, North Carolina State University, Raleigh, NC 27695-7617, USA; Carolina AquaGyn, P.O. Box 12914, Raleigh, NC 27605, USA(1)
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Fazielawanie NMR, Siraj SS, Harmin SA, Ina-Salwany MY. Isolation and partial characterization of Asian sea bass (Lates calcarifer) Vitellogenin. FISH PHYSIOLOGY AND BIOCHEMISTRY 2013; 39:191-200. [PMID: 22878544 PMCID: PMC3601245 DOI: 10.1007/s10695-012-9690-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2012] [Accepted: 07/04/2012] [Indexed: 05/23/2023]
Abstract
A study was conducted to isolate, partial characterize Asian sea bass (Lates calcarifer) vitellogenin (vtg). Two-year-old juvenile L. calcarifer (n = 10) were given three intraperitoneal injections of 17-β estradiol (E2) at a dose of 2 mg/kg body weight to induce vitellogenesis. Blood was collected 3 days after the last injection, and plasma was purified through gel filtration chromatography. A broad single symmetrical peak consisting of vtg molecule was produced. Protein concentration was 0.059 mg/ml as determined by Bradfrod assay using bovine serum albumin as a standard. The protein appeared as one circulating form in Native PAGE considering the dimeric form of putative vtg with molecular weight of 545 kDa. In SDS-PAGE under reducing conditions, two major bands appeared at 232.86 and 118.80 kDa and minor bands at 100.60, 85.80 and 39.92 kDa, respectively. The purified vtg was used to generate a polyclonal antibody, and the specificity of antibody was assessed by Western blot analysis. Two major bands were immunoreacted, but no cross-reactivity was observed with plasma from non-induced males. The protein was characterized as phosphoglycolipoprotein as it positively stained for the presence of lipid, phosphorus and carbohydrate using Sudan Black B, methyl green and periodic acid/Schiff reagent solution, respectively. The amino acid composition was analyzed by high sensitivity amino acid analysis that showed high percentage of non-polar amino acids (~48 %). The results suggest the potential utilization of vtg as a basis tool to further study about reproductive physiology of this important economical species.
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Affiliation(s)
- N. M. R. Fazielawanie
- Department of Aquaculture, Faculty of Agriculture, University Putra Malaysia (UPM), 43400 Serdang, Selangor Malaysia
| | - S. S. Siraj
- Department of Aquaculture, Faculty of Agriculture, University Putra Malaysia (UPM), 43400 Serdang, Selangor Malaysia
| | - S. A. Harmin
- Centre for Land and Aquatic Technology, Faculty of Science and Biotechnology, University Industry Selangor (UNISEL), 45600 Batang Berjuntai, Selangor Malaysia
| | - M. Y. Ina-Salwany
- Department of Aquaculture, Faculty of Agriculture, University Putra Malaysia (UPM), 43400 Serdang, Selangor Malaysia
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Molés G, Gómez A, Carrillo M, Zanuy S. Development of a homologous enzyme-linked immunosorbent assay for European sea bass FSH. Reproductive cycle plasma levels in both sexes and in yearling precocious and non-precocious males. Gen Comp Endocrinol 2012; 176:70-8. [PMID: 22227219 DOI: 10.1016/j.ygcen.2011.12.029] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 12/19/2011] [Accepted: 12/21/2011] [Indexed: 12/21/2022]
Abstract
Since the late 1980s, gonadotropins have been isolated and characterized in several fish species, but specific immunoassays for the follicle-stimulating hormone (FSH) have only been developed for a few. The present study reports the development and use of a specific and homologous competitive ELISA for measuring FSH in European sea bass (Dicentrarchus labrax) using a recombinant FSH and its specific antiserum. Recombinant European sea bass FSHβ and FSH heterodimer were produced in the methylotrophic yeast Pichia pastoris and a baculovirus expression system, respectively. Specific polyclonal antibodies, generated by rabbit immunization against recombinant FSHβ, were used at a final dilution of 1:8000. Recombinant FSH heterodimer was used to generate a standard curve and for coating of microplates (166 μg/ml). The sensitivity of the assay was 0.5 ng/ml [B(0)-2SD], and the intra- and inter-assay coefficients of variation were 2.12% (n=10) and 5.44% (n=16) (B(i)/B(0) ∼45%), respectively. A high degree of parallelism was observed between the standard curve and serially diluted plasma and pituitary samples of European sea bass. The ELISA developed was used to study the plasma FSH profiles of mature males and females during the reproductive cycle, and those of immature juvenile males under different light regimes. The analysis showed that FSH increased significantly during the intermediate stages of spermatogenesis and during vitellogenesis. Analyses in immature juvenile males showed that the continuous light photoperiod significantly reduced plasma FSH levels, and consequently, testicular growth and precocious puberty. In conclusion, the immunoassay developed has proven to be sensitive, specific and accurate for measuring European sea bass FSH, and it represents a valuable tool for future studies on the reproductive endocrinology of this species.
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Affiliation(s)
- Gregorio Molés
- Department of Fish Physiology and Biotechnology, Institute of Aquaculture Torre de Sal, Spanish National Research Council (CSIC), Torre de Sal s/n, 12595 Ribera de Cabanes, Castellón, Spain
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Molés G, Gómez A, Carrillo M, Rocha A, Mylonas CC, Zanuy S. Determination of Fsh Quantity and Bioactivity During Sex Differentiation and Oogenesis in European Sea Bass1. Biol Reprod 2011; 85:848-57. [DOI: 10.1095/biolreprod.111.091868] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
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Correia AD, Freitas S, Scholze M, Goncalves JF, Booij P, Lamoree MH, Mañanós E, Reis-Henriques MA. Mixtures of estrogenic chemicals enhance vitellogenic response in sea bass. ENVIRONMENTAL HEALTH PERSPECTIVES 2007; 115 Suppl 1:115-21. [PMID: 18174959 PMCID: PMC2174414 DOI: 10.1289/ehp.9359] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2006] [Accepted: 09/05/2006] [Indexed: 05/22/2023]
Abstract
BACKGROUND The potential impact of natural and synthetic estrogens on aquatic ecosystems has attracted considerable attention because it is currently accepted that their joint effects are more severe when they are present in mixtures. Although it is well-known that they occur as mixtures in the marine environment, there is little information about the combined effects of estrogenic chemicals on marine biota. OBJECTIVE In 14-day tests with juvenile sea bass, we analyzed singly and in combination the estrogenic activity of estradiol (E(2)), ethynylestradiol (EE(2)), and bisphenol A (BPA) using vitellogenin induction as an end point. METHODS Fish were exposed to each compound, and on the basis of these concentration-response data, we predicted mixture effects by applying the model of concentration addition. The mixtures were tested using a fixed-ratio design, and the resulting mixture effects were compared to the predictions. RESULTS EE(2) was the most potent steroid, with an EC(50) (median effective concentration) of 0.029 microg/L, 3.6 times more potent than E(2) (EC(50) = 0.104 microg/L); BPA was the least potent chemical, with an EC(50) of 77.94 microg/L. The comparative assessment yielded a good agreement between observed and predicted mixture effects. CONCLUSIONS This study demonstrates the potential hazard of these compounds to seawater life by their ability to act together in an additive manner. It provides evidence that concentration addition can be used as a predictive tool for assessing the combined effects of estrogenic chemicals in marine ecosystems.
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Affiliation(s)
- Ana D Correia
- CIIMAR-Centre of Marine and Environmental Research, Environmental Toxicology Laboratory, Porto, Portugal.
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Ndiaye P, Forgue J, Lamothe V, Cauty C, Tacon P, Lafon P, Davail B, Fostier A, Le Menn F, Núñez J. Tilapia (Oreochromis niloticus) vitellogenins: development of homologous and heterologous ELISAs and analysis of vitellogenin pathway through the ovarian follicle. ACTA ACUST UNITED AC 2006; 305:576-93. [PMID: 16615099 DOI: 10.1002/jez.a.290] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Vitellogenin (VTG) of Oreochromis niloticus was again purified, due to the conflicting results found in the literature. Three purification processes have been used: electrophoresis and electro-elution, double chromatography (gel filtration and ion-exchange chromatography) and single ion-exchange chromatography. Using SDS-PAGE we confirmed in all cases the presence of two polypeptidic forms of plasma VTG of 130 kDa (VTG1) and 170 kDa (VTG2). We raised polyclonal antibodies against each VTG form and we demonstrated the complete cross-reactivity of each antibody with both forms of VTG by Enzyme Immuno-Assay (EIA) and Western blots. The homologous ELISAs developed exhibited a detection limit of 6 ng x ml(-1), equivalent to 60 ng x ml(-1) of plasma VTG and allowed us to quantify the total plasma VTG of O. niloticus with high specificity and sensitivity. Using photonic and electron immunomicroscopy, we followed the pathway of VTG into the ovarian follicle (OF) demonstrating that VTG enters the oocyte at stage 3 of OF development, at the same time as cortical alveoli and lipid globules appear. Heterologous ELISAs performed on other cichlid species allowed us to quantify plasma VTG in Oreochromis aureus and Sarotherodon melanotheron and to detect it in Hemichromis fasciatus, Hemichromis bimaculatus and Tilapia zillii, constituting a reliable tool for monitoring the presence of xeno-estrogens in the environment of these fish species.
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Affiliation(s)
- Pap Ndiaye
- IFAN, Université Cheikh Anta Diop, Dakar, Sénégal
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Piferrer F, Blázquez M, Navarro L, González A. Genetic, endocrine, and environmental components of sex determination and differentiation in the European sea bass (Dicentrarchus labrax L.). Gen Comp Endocrinol 2005; 142:102-10. [PMID: 15862554 DOI: 10.1016/j.ygcen.2005.02.011] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2004] [Revised: 02/14/2005] [Accepted: 02/14/2005] [Indexed: 10/25/2022]
Abstract
The European sea bass (Dicentrarchus labrax L.) is a differentiated gonochoristic marine teleost of the family Moronidae (closely related to the hermaphrodites of the family Serranidae), where many juvenile males exhibit intratesticular oocytes, suggesting a certain sexual lability. Like most fish, the sea bass does not have recognizable heterochromosomes or sex-linked markers but there are clear parental effects on the sex ratios. The data available so far indicate that the proportion of females resulting from individual crossings may range from as little as 1 to about 70%. Sex differentiation proceeds in a caudo-cranial fashion and starts when fish reach 8-9 cm standard length (usually about 200 days post-hatching, dph, under typical rearing conditions), with females differentiating first. Both forms of aromatase have been cloned in this species and their temporal expression has been studied. Brain aromatase is detectable already in the larval stages but its involvement in sex differentiation is not yet clear. The ovarian form increases after 100 dph before ovarian differentiation, with high levels in females and basal levels in males. Thus, ovarian aromatase seems to be involved in female differentiation. On the other hand, androgen receptor (AR) gene expression levels show the opposite pattern, with higher levels in males than in females. It is not yet known whether androgens are necessary for testicular differentiation or rather they are the result of it. Of the several environmental factors tested, temperature is the only one that has been shown to be able to clearly influence sex ratios. Larval and juvenile sea bass reared in captivity at high temperature usually develop as males. Recent research suggests that the high incidence of males under aquaculture conditions is due to the high water temperature used, and that the effects of temperature would be mediated by an inhibition of aromatase mRNA expression and activity in genotypic females. However, other effects of temperature mediated through alterations in developmental rates cannot be discarded. This paper reviews the current knowledge on sex determination and differentiation in the sea bass and suggests some directions for future research.
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Affiliation(s)
- Francesc Piferrer
- Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.
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Sehgal N, Goswami SV. Vitellogenin exists as charge isomers in the Indian freshwater murrel, Channa punctatus (Bloch). Gen Comp Endocrinol 2005; 141:12-21. [PMID: 15707599 DOI: 10.1016/j.ygcen.2004.10.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2004] [Revised: 09/01/2004] [Accepted: 10/20/2004] [Indexed: 11/26/2022]
Abstract
Three charge isomeric forms of vitellogenin are reported in the blood of estrogen-treated murrel, Channa punctatus on the basis of the results of native and SDS-PAGE, isoelectric focusing, and Ferguson plot analysis. Vitellogenin was induced in adult murrels by exogenous administration of estradiol-17beta and labelled with 32P in vivo. Labelled vitellogenin isolated from other plasma proteins on Ultrogel AcA 34 columns resolve into three bands on native-PAGE. Ferguson plot analysis reveals free electrophoretic mobilities of the three bands as 6.0, 4.5, and 3.7, which are very similar to the isoelectric point values of 5.9, 4.6, and 3.8, respectively. The apparent molecular weight of native murrel vitellogenin is 530 kDa. It consists of a single peptide with a molecular weight of 175 kDa. All the three bands on native PAGE resolves into a single peptide on SDS-PAGE. N-terminal amino acid sequence for murrel vitellogenin peptide is MKAVVLALLL. The protein phosphorus:lipid phosphorus ratio for murrel vitellogenin is 0.9. The total lipid content is 32.8%, consisting of 45% neutral lipids and 30% phospholipids. Phosphatidyl choline is the major phospholipid whereas triglycerides are the major neutral lipids. Results of these analytical analyses indicate that murrel native vitellogenin circulates as three charge isomers; poor in phosphorus but rich in lipids content.
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Affiliation(s)
- Neeta Sehgal
- Department of Zoology, University of Delhi, Delhi 110 007, India
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Roy RL, Morin Y, Courtenay SC, Robichaud P. Purification of vitellogenin from smooth flounder (Pleuronectes putnami) and measurement in plasma by homologous ELISA. Comp Biochem Physiol B Biochem Mol Biol 2004; 139:235-44. [PMID: 15465670 DOI: 10.1016/j.cbpc.2004.07.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2004] [Revised: 07/21/2004] [Accepted: 07/21/2004] [Indexed: 10/26/2022]
Abstract
Male smooth flounder (Pleuronectes putnami) were induced to produce vitellogenin (VTG) by injection of 17beta-estradiol (E2). Anion exchange chromatography of precipitated plasma from E2-injected resulted in a single peak consisting of VTG. Smooth flounder VTG has an approximate molecular mass of approximately 520 kDa, determined by gel filtration with molecular weight standards. Purified VTG was used to develop a homologous enzyme-linked immunosorbent assay (ELISA). The flounder VTG ELISA is an indirect antigen competition assay with a detection limit of 15 ng.ml(-1) and a useful range of 30-950 ng.ml(-1) of diluted sample. Intra- and inter-assay precision (as %CV, n=7) ranged from 1.3% to 6.0% and 5.1%, respectively. The ELISA was evaluated using plasma samples collected from a smooth flounder population captured in the Saint Lawrence Estuary. The ELISA is sensitive enough to differentiate males and non-vitellogenic females from vitellogenic individuals during early vitellogenesis.
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Affiliation(s)
- Robert L Roy
- Pêches et Océans Canada, Institut Maurice-Lamontage, Mont-Joli, Québec, Canada G5H 3Z4.
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Islinger M, Yuan H, Voelkl A, Braunbeck T. Measurement of vitellogenin gene expression by RT-PCR as a tool to identify endocrine disruption in Japanese medaka (Oryzias latipes). Biomarkers 2002; 7:80-93. [PMID: 12101787 DOI: 10.1080/13547500110086919] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In order to monitor vitellogenin gene expression in the Japanese medaka (Oryzias latipes), a reverse transcription-polymerase chain reaction (RT-PCR) system was developed. To date cDNA for medaka vitellogenin has not been published; therefore, initially a sequence fragment had to be obtained and compared with other known vertebrate vitellogenins. For this, a 1.2 kb cDNA of medaka vitellogenin (M-Vg1.2) was amplified by RT-PCR and cloned into a pCRR H-TOPO bacterial vector. On Northern blot analysis, the antisense cRNA of M-Vg1.2 stained a 5.5 kb gene product found exclusively in female fish, but not in males. Additionally, the 5'-end of medaka vitellogenin cDNA was amplified by 5'-RACE-PCR. The analysed nucleotide sequence of 1.6 kb shared significant similarities with vitellogenins known from other fish species: approximately 72% similarity with mummichog (Fundulus heteroclitus) vitellogenin I and approximately 62% with fathead minnow (Pimephales promelas) vitellogenin. To develop a semiquantitative RT-PCR for the measurement of vitellogenin gene expression, primers specific to a 500 bp sequence of the vitellogenin cDNA (M-Vg0.5) were constructed using the gene product of elongation factor 1 alpha as internal standard. Induction of vitellogenin gene expression was measured in male medaka exposed to 0, 2, 20 and 50 micrograms l-1 nonylphenol and 0, 2.5, 25 and 100 ng l-1 17 alpha-ethinyloestradiol for 7 days. The LOECs for vitellogenin induction in male medaka were 20 micrograms l-1 and 25 ng l-1 for nonylphenol and 17 alpha-ethinyloestradiol, respectively.
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Affiliation(s)
- M Islinger
- Department of Zoology, Aquatic Ecology and Toxicology Section, University of Heidelberg, Im Neuenheimer Feld 230, D-69120 Heidelberg, Germany.
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