@article {9313, title = {Duplicated paralog of sulfide: quinone oxidoreductase contributes to the adaptation to hydrogen sulfide-rich environment in the hydrothermal vent crab, Xenograpsus testudinatus}, journal = {Science of The Total Environment}, volume = {890}, year = {2023}, month = {Jan-09-2023}, pages = {164257}, issn = {00489697}, doi = {10.1016/j.scitotenv.2023.164257}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0048969723028784}, author = {Chen, Chi and Wu, Guan-Chung and Chung, Yao-Tse and Li, Hau-Wen and Chou, Pei-Hsuan and Tseng, Yung-Che and Chen, Chieh-Jhen and Sylvie Dufour and Chang, Ching-Fong} } @article {8955, title = {Dynamic evolution of transient receptor potential vanilloid (TRPV) ion channel family with numerous gene duplications and losses}, journal = {Frontiers in Endocrinology}, volume = {13}, year = {2022}, month = {Jan-11-2022}, doi = {10.3389/fendo.2022.1013868}, url = {https://www.frontiersin.org/articles/10.3389/fendo.2022.1013868/full}, author = {Morini, Marina and Bergqvist, Christina A. and Asturiano, Juan F. and Larhammar, Dan and Sylvie Dufour} } @article {8797, title = {New Insights Into the Evolution of Corticotropin-Releasing Hormone Family With a Special Focus on Teleosts}, journal = {Frontiers in Endocrinology}, volume = {13}, year = {2022}, pages = {937218}, doi = {Doi: 10.3389/fendo.2022.937218}, author = {Maugars, Gersende and Mauvois, Xavier and Martin, Patrick and Rousseau, Karine and Aroua, Salima and Sylvie Dufour} } @article {9312, title = {Tachykinins, new players in the control of reproduction and food intake: A comparative review in mammals and teleosts}, journal = {Frontiers in Endocrinology}, volume = {13}, year = {2022}, month = {Apr-12-2023}, doi = {10.3389/fendo.2022.1056939}, url = {https://www.frontiersin.org/articles/10.3389/fendo.2022.1056939/full}, author = {Campo, Aurora and Sylvie Dufour and Rousseau, Karine} } @article {8086, title = {The Chicken and Egg Situation of Thyroid Hormone and Glucocorticoid Signaling during Postembryonic Development}, journal = {Endocrinology}, volume = {162}, year = {2021}, month = {Jan-03-2021}, issn = {0013-7227}, doi = {10.1210/endocr/bqaa243}, url = {https://academic.oup.com/endo/article/doi/10.1210/endocr/bqaa243/6054192}, author = {Sylvie Dufour and Sachs, Laurent M} } @article {8798, title = {Interdependence of thyroid and corticosteroid signalling in vertebrate developmental transitions}, journal = {Frontiers in Ecology and Evolution}, volume = {9}, year = {2021}, pages = {735487}, doi = {10.3389/fevo.2021.735487}, author = {Karine Rousseau and Sylvie Dufour and Sachs, Laurent M} } @article {8446, title = {Involvement of RFamide neuropeptides in polyp contraction of the adult scleractinian corals Euphyllia ancora and Stylophora pistillata}, journal = {General and Comparative Endocrinology}, volume = {314}, year = {2021}, month = {Jan-12-2021}, pages = {113905}, issn = {00166480}, doi = {10.1016/j.ygcen.2021.113905}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0016648021001982}, author = {Zhang, Yan and Shikina, Shinya and Ho, Yu-Ying and Chiu, Yi-Ling and I-Chen Yao, Jack and C{\'e}line Zatylny-Gaudin and Sylvie Dufour and Chang, Ching-Fong} } @article {8794, title = {Involvement of Transforming Growth Factor Beta family genes in gonadal differentiation in Japanese eel, Anguilla japonica, according to sex-related gene expressions}, journal = {Cells}, volume = {10}, year = {2021}, pages = {3007}, url = {https://doi.org/10.3390/cells10113007}, author = {Lin, Chien-Ju and Jeng, Shan-Ru and Lei, Zhen-Yuan and Yueh, When-Shiun and Sylvie Dufour and Wu, Guan-Chung and Chang, Ching-Fong} } @article {8085, title = {Molecular and cellular regulation on sex change in hermaphroditic fish, with a special focus on protandrous black porgy, Acanthopagrus schlegelii.}, journal = {Mol Cell Endocrinol}, volume = {520}, year = {2021}, month = {2021 01 15}, pages = {111069}, abstract = {

In teleost fish, sex can be determined by genetic factors, environmental factors, or both. Unlike in gonochoristic fish, in which sex is fixed in adults, sex can change in adults of hermaphroditic fish species. Thus, sex is generated during the initial gonadal differentiation stage (primary sex differentiation) and later during sexual fate alternation (secondary sex differentiation) in hermaphroditic fish species. Depending on the species, sex phase alternation can be induced by endogenous cues (such as individual age and body size) or by social cues (such as sex ratio or relative body size within the population). In general, the fluctuation in plasma estradiol-17β (E2) levels is correlated with the sexual fate alternation in hermaphroditic fish. Hormonal treatments can artificially induce sexual phase alternation in sequential hermaphroditic fishes, but in a transient and reversible manner. This is the case for the E2-induced female phase in protandrous black porgy and the methyltestosterone (MT)- or aromatase inhibitor (AI)-induced male phase in protogynous grouper. Recent reviews have focused on the different forms of sex change in fish who undergo sequential sex change, especially in terms of gene expression and the role of hormones. In this review, we use the protandrous black porgy, a nonsocial cue-influenced hermaphroditic species, with digonic gonads (ovarian and testis separated by a connective tissue), as a model to describe our findings and discuss the molecular and cellular regulation of sexual fate determination in hermaphroditic fish.

}, issn = {1872-8057}, doi = {10.1016/j.mce.2020.111069}, author = {Wu, Guan-Chung and Sylvie Dufour and Chang, Ching-Fong} } @article {8083, title = {Photoperiodic regulation of pituitary thyroid-stimulating hormone and brain deiodinase in Atlantic salmon}, journal = {Molecular and Cellular Endocrinology}, volume = {519}, year = {2021}, month = {Jan-01-2021}, pages = {111056}, issn = {03037207}, doi = {10.1016/j.mce.2020.111056}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0303720720303580}, author = {Irachi, Shotaro and Hall, Daniel J. and Fleming, Mitchell S. and Maugars, Gersende and Bj{\"o}rnsson, Bj{\"o}rn Thrandur and Sylvie Dufour and Uchida, Katsuhisa and McCormick, Stephen D.} } @article {8084, title = {Special features of neuroendocrine interactions between stress and reproduction in teleosts}, journal = {General and Comparative Endocrinology}, volume = {300}, year = {2021}, month = {Jan-01-2021}, pages = {113634}, issn = {00166480}, doi = {10.1016/j.ygcen.2020.113634}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0016648020303877}, author = {Rousseau, Karine and Prunet, Patrick and Sylvie Dufour} } @article {7133, title = {Basal teleosts provide new insights into the evolutionary history of teleost-duplicated aromatase}, journal = {General and Comparative Endocrinology}, volume = {291}, year = {2020}, month = {Jan-05-2020}, pages = {113395}, issn = {00166480}, doi = {10.1016/j.ygcen.2020.113395}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0016648019303326}, author = {Lin, Chien-Ju and Maugars, Gersende and Lafont, Anne-Gaelle and Jeng, Shan-Ru and Wu, Guan-Chung and Sylvie Dufour and Chang, Ching-Fong} } @article {8080, title = {Differential Regulation of the Expression of the Two Thyrotropin Beta Subunit Paralogs by Salmon Pituitary Cells In Vitro}, journal = {Frontiers in Endocrinology}, volume = {11}, year = {2020}, month = {Mar-11-2022}, doi = {10.3389/fendo.2020.603538}, url = {https://www.frontiersin.org/articles/10.3389/fendo.2020.603538/full}, author = {Fleming, Mitchell Stewart and Maugars, Gersende and Martin, Patrick and Sylvie Dufour and Rousseau, Karine} } @article {8081, title = {Elevated estradiol-17β levels inhibit final oocyte maturation via G protein-coupled estrogen receptor (Gper) in yellowfin porgy, Acanthopagrus latus}, journal = {General and Comparative Endocrinology}, volume = {299}, year = {2020}, month = {Jan-12-2020}, pages = {113587}, issn = {00166480}, doi = {10.1016/j.ygcen.2020.113587}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0016648020303403}, author = {Jeng, Shan-Ru and Thomas, Peter and Pang, Yefei and Sylvie Dufour and Lin, Chien-Ju and Yueh, Wen-Shiun and Chang, Ching-Fong} } @inbook {7274, title = {Endocrinology: An evolutionary perspective on neuroendocrine axes in teleosts}, booktitle = {The Physiology of Fishes, Fifth Edition}, year = {2020}, pages = {105-116}, publisher = {CRC Press, Taylor \& Francis Group}, organization = {CRC Press, Taylor \& Francis Group}, edition = {Suzanne Curie and David H. Evans, Editors}, chapter = {8}, address = {Boca Raton,FL}, issn = {9781003036401}, doi = {10.1201/9781003036401 }, author = {Sylvie Dufour and Karine Rousseau} } @article {7134, title = {Gonadotropin-inhibitory hormone in teleosts: New insights from a basal representative, the eel}, journal = {General and Comparative Endocrinology}, volume = {287}, year = {2020}, month = {Jan-02-2020}, pages = {113350}, issn = {00166480}, doi = {10.1016/j.ygcen.2019.113350}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0016648019303296}, author = {Maugars, G. and Pasquier, J. and Atkinson, C. and Lafont, A.-G. and Campo, A. and Kamech, Nedia and Lefranc, B. and Leprince, J. and Sylvie Dufour and Rousseau, K.} } @article {7131, title = {Identification and stable expression of vitellogenin receptor through vitellogenesis in the European eel}, journal = {animal}, volume = {14}, year = {2020}, month = {Jan-06-2020}, pages = {1213 - 1222}, issn = {1751-7311}, doi = {10.1017/S1751731119003355}, url = {https://www.cambridge.org/core/product/identifier/S1751731119003355/type/journal_article}, author = {Morini, M. and Lafont, A. G. and Maugars, G. and Baloche, S. and Sylvie Dufour and Asturiano, J. F. and P{\'e}rez, L.} } @article {8082, title = {The life and times of Olivier Kah through the lens of fish endocrinologists}, journal = {General and Comparative Endocrinology}, volume = {293}, year = {2020}, month = {Jan-07-2020}, pages = {113480}, issn = {00166480}, doi = {10.1016/j.ygcen.2020.113480}, url = {https://linkinghub.elsevier.com/retrieve/pii/S001664802030188X}, author = {Trudeau, Vance L. and Sylvie Dufour and Prunet, Patrick} } @article {7132, title = {Origin and Evolution of the Neuroendocrine Control of Reproduction in Vertebrates, With Special Focus on Genome and Gene Duplications}, journal = {Physiological Reviews}, volume = {100}, year = {2020}, month = {Jan-04-2020}, pages = {869 - 943}, issn = {0031-9333}, doi = {10.1152/physrev.00009.2019}, url = {https://journals.physiology.org/doi/10.1152/physrev.00009.2019}, author = {Sylvie Dufour and Qu{\'e}rat, Bruno and Tostivint, Herv{\'e} and Pasqualini, Catherine and Vaudry, Hubert and Rousseau, Karine} } @article {7273, title = {Unidirectional response to bidirectional selection on body size. I. Phenotypic, life-history, and endocrine responses}, journal = {Ecology and Evolution}, year = {2020}, month = {Jan-09-2021}, issn = {2045-7758}, doi = {10.1002/ece3.6713}, url = {https://onlinelibrary.wiley.com/doi/10.1002/ece3.6713}, author = {Renneville, Cl{\'e}mentine and Millot, Alexis and Agostini, Simon and Carmignac, David and Maugars, Gersende and Sylvie Dufour and Le Rouzic, Arnaud and Edeline, Eric} } @article {7272, title = {Unravelling the changes during induced vitellogenesis in female European eel through RNA-Seq: What happens to the liver?}, journal = {PLOS ONE}, volume = {15}, year = {2020}, month = {Jan-08-2021}, pages = {e0236438}, doi = {10.1371/journal.pone.023643810}, url = {https://dx.plos.org/10.1371/journal.pone.0236438}, author = {Bertolini, Francesca and J{\o}rgensen, Michelle Grace Pinto and Henkel, Christiaan and Sylvie Dufour and Tomkiewicz, Jonna} } @article {6017, title = {Activation of the brain-pituitary-gonadotropic axis in the black porgy Acanthopagrus schlegelii during gonadal differentiation and testis development and effect of estradiol treatment.}, journal = {General and Comparative Endocrinology}, volume = {281}, year = {2019}, pages = {17-29}, author = {Lin, Chien-Ju and Wu, Guan-Chung and Sylvie Dufour and Chang, Ching-Fong} } @article {6016, title = {Dmrt1 (doublesex and mab-3-related transcription factor 1) expression during gonadal development and spermatogenesis in the Japanese eel.}, journal = {General and Comparative Endocrinology}, volume = {279}, year = {2019}, pages = {154-163}, author = {Jeng, Shan-Ru and Wu, Guan-Chung and Wen-Shiun Yueh and Kuo, S-F and Sylvie Dufour and Chang, Ching-Fong} } @article {6018, title = {Functional divergence of thyrotropin beta-subunit paralogs gives new insights into salmon smoltification metamorphosis}, journal = {Scientific Reports}, volume = {9}, year = {2019}, pages = {4561}, author = {Fleming, Mitchell S and Maugars, Gersende and Lafont, Anne-Gaelle and Rancon, Jocelyn and Fontaine, Romain and Nourizadeh-Lillabadi, Rasoul and Weltzien, Finn-Arne and Santidrian Yebra-Pimentel, Elena and Dirks, Ron and McCormick, Stephen D and Rousseau, Karine and Martin, Patrick and Sylvie Dufour} } @article {5662, title = {Characterization of gonadotropin-releasing hormone (GnRH) genes from cartilaginous fish: evolutionary perspectives.}, journal = {Frontiers in Neuroscience}, volume = {12}, year = {2018}, pages = {607}, author = {Gaillard, A-L and Tay, Boon-Hui and Perez-Sirkin, Daniela and Anne-Gaelle Lafont and De Flori, C{\'e}line and Vissio, Paula G. and Mazan, Sylvie and Sylvie Dufour and Venkatesh, Byrappa and Tostivint, Herv{\'e}} } @article {5422, title = {Differential expression of gonadotropin and estrogen receptors and oocyte cytology during follicular maturation associated with egg viability in European eel (Anguilla anguilla)}, journal = {Comparative Biochemistry and Physiology, Part A}, volume = {221}, year = {2018}, pages = {44-54}, url = {https://doi.org/10.1016/j.cbpa.2018.03.010}, author = {da Silva, F F G and Tveiten, H and Gersende Maugars and Anne-Gaelle Lafont and Sylvie Dufour and St{\o}ttrupa, J G and Kj{\o}rsvikd, E and Tomkiewicz, J} } @article {5421, title = {Eel Kisspeptins: identification, functional activity, and inhibition on both pituitary LH and GnRH receptor expression}, journal = {Frontiers in Endocrinology}, volume = {8}, year = {2018}, pages = {353}, abstract = {

The European eel (Anguilla anguilla) presents a blockade of sexual maturation at a prepubertal stage due to a deficient production of gonadotropins. We previously initiated, in the eel, the investigation of the kisspeptin system, one of the major gatekeepers of puberty in mammals, and we predicted the sequence of two Kiss genes. In the present study, we cloned and sequenced Kiss1 and Kiss2 cDNAs from the eel brain. The tissue distributions of Kiss1 and Kiss2 transcripts, as investigated by quantitative real-time PCR, showed that both genes are primarily expressed in the eel brain and pituitary. The two 10-residue long sequences characteristic of kisspeptin, eel Kp1(10) and Kp2(10), as well as two longer sequences, predicted as mature peptides, eel Kp1(15) and Kp2(12), were synthesized and functionally analyzed. Using rat Kiss1 receptor-transfected Chinese hamster ovary cells, we found that the four synthesized eel peptides were able to induce [Ca2+]i responses, indicating their ability to bind mammalian KissR-1 and to activate second messenger pathways. In primary culture of eel pituitary cells, all four peptides were able to specifically and dose-dependently inhibit lhβ expression, without any effect on fshβ, confirming our previous data with heterologous kisspeptins. Furthermore, in this eel in vitro system, all four peptides inhibited the expression of the type 2 GnRH receptor (gnrh-r2). Our data revealed a dual inhibitory effect of homologous kisspeptins on both pituitary lhβ and gnrh-r2 expression in the European eel.

}, doi = {10.3389/fendo.2017.00353}, author = {Pasquier, J and Anne-Gaelle Lafont and Florian, D and Lefranc, B and Dubessy, C and Moreno-Herrera, A and Vaudry, H and Leprince, J and Sylvie Dufour and Karine Rousseau} } @article {5583, title = {Tachykinin-3 Genes and Peptides Characterized in a Basal Teleost, the European Eel: Evolutionary Perspective and Pituitary Role.}, journal = {Frontiers in Endocrinology}, volume = {9}, year = {2018}, pages = {304}, author = {Campo, Aurora and Anne-Gaelle Lafont and Lefranc, Benjamin and Leprince, J{\'e}r{\^o}me and Tostivint, Herv{\'e} and Kamech, Nedia and Sylvie Dufour and Karine Rousseau} } @article {5222, title = {Conservation of Three-Dimensional Helix-Loop-Helix Structure through the Vertebrate Lineage Reopens the Cold Case of Gonadotropin-Releasing Hormone-Associated Peptide}, journal = {Frontiers in Endocrinology}, volume = {8}, year = {2017}, pages = {207}, abstract = {

GnRH associated peptide (GAP) is the C-terminal portion of the GnRH preprohormone. Although it was reported in mammals that GAP may act as a prolactin-inhibiting factor and can be co-secreted with GnRH into the hypophyseal portal blood, GAP has been practically out of the research circuit for about 20 years. Comparative studies highlighted the low conservation of GAP primary amino acid sequences among vertebrates, contributing to consider that this peptide only participates in the folding or carrying process of GnRH. Considering that the tridimensional (3D) structure of a protein may define its function, the aim of this study was to evaluate if GAP sequences and 3D structures are conserved in the vertebrate lineage. GAP sequences from various vertebrates were retrieved from databases. Analysis of primary amino acid sequence identity and similarity, molecular phylogeny, and prediction of 3D structures were performed. Amino acid sequence comparison and phylogeny analyses confirmed the large variation of GAP sequences throughout vertebrate radiation. In contrast, prediction of the 3D structure revealed a striking conservation of the 3D structure of GAP1 (GAP associated with the hypophysiotropic type 1 GnRH), despite low amino acid sequence conservation. This GAP1 peptide presented a typical helix-loop-helix (HLH) structure in all the vertebrate species analyzed. This HLH structure could also be predicted for GAP2 in some but not all vertebrate species, and in none of the GAP3 analyzed. These results allowed us to infer that selective pressures have maintained GAP1 HLH structure throughout the vertebrate lineage. The conservation of the HLH motif, known to confer biological activity to various proteins, suggests that GAP1 peptides may exert some hypophysiotropic biological functions across vertebrate radiation.

}, issn = {1664-2392}, doi = {10.3389/fendo.2017.00207}, url = {https://www.frontiersin.org/article/10.3389/fendo.2017.00207}, author = {P{\'e}rez Sirkin, Daniela I. and Anne-Gaelle Lafont and Kamech, Nedia and Somoza, Gustavo M. and Vissio, Paula G. and Sylvie Dufour} } @article {4755, title = {The expression of nuclear and membrane estradiol receptors in the European eel throughout spermatogenesis.}, journal = {Comparative Biochemistry and Physiology, Part A}, volume = {203}, year = {2017}, pages = {91-99}, author = {Morini, Marina and Penaranda, David S and V{\'\i}lchez, M C and Tveiten, Helge and Anne-Gaelle Lafont and Sylvie Dufour and P{\'e}rez, L and Asturiano, J F} } @article {4756, title = {Nuclear and membrane progestin receptors in the European eel: characterization and expression in vivo through spermatogenesis}, journal = {Comparative Biochemistry and Physiology, Part A}, volume = {207}, year = {2017}, pages = {79-92}, author = {Morini, Marina and Penaranda, David S and V{\'\i}lchez, M C and Nourizadeh-Lillabadi, R and Anne-Gaelle Lafont and Sylvie Dufour and Asturiano, J F and Weltzien, Finn-Arne and Perez, Luz} } @article {5016, title = {Rapid de novo assembly of the European eel genome from nanopore sequencing reads}, journal = {Scientific Reports}, volume = {7}, year = {2017}, pages = {7213}, author = {J. Jansen and M. Liem and S. Jong-Raadsen and Sylvie Dufour and Weltzien, Finn-Arne and W. Swinkels and A. Koelewijn and A. Palstra and B. Pelster and H. Spaink and G. van den Thillart and Dirks, Ron and Christiaan V Henkel} } @article {4757, title = {Recurrent DCC gene losses during bird evolution}, journal = {Scientific Reports}, volume = {7}, year = {2017}, pages = {37569}, author = {Friocourt, Fran{\c c}ois and Anne-Gaelle Lafont and Kress, Cl{\'e}mence and Pain, Bertrand and Manceau, Marie and Sylvie Dufour and Chedotal, Alain} } @article {4506, title = {Activation of brain steroidogenesis and neurogenesis during the gonadal differentiation in protandrous black porgy, Acanthopagrus schlegelii.}, journal = {Dev Neurobiol}, volume = {76}, year = {2016}, month = {2016 Feb}, pages = {121-36}, abstract = {

The early brain development, at the time of gonadal differentiation was investigated using a protandrous teleost, black porgy. This natural model of monosex juvenile fish avoids the potential complexity of sexual dimorphism. Brain neurogenesis was evaluated by histological analyses of the diencephalon, at the time of testicular differentiation (in fish between 90 and 150 days after hatching). Increases in the number of both Nissl-stained total brain cells, and Pcna-immunostained proliferative brain cells were observed in specific area of the diencephalon, such as ventromedialis thalami and posterior preoptic area, revealing brain cell proliferation. qPCR analyses showed significantly higher expression of the radial glial cell marker blbp and neuron marker bdnf. Strong immunohistochemical staining of Blbp and extended cellular projections were observed. A peak expression of aromatase (cyp19a1b), as well as an increase in estradiol (E2 ) content were also detected in the early brain. These data demonstrate that during gonadal differentiation, the early brain exhibits increased E2 synthesis, cell proliferation, and neurogenesis. To investigate the role of E2 in early brain, undifferentiated fish were treated with E2 or aromatase inhibitor (AI). E2 treatment upregulated brain cyp19a1b and blbp expression, and enhanced brain cell proliferation. Conversely, AI reduced brain cell proliferation. Castration experiment did not influence the brain gene expression patterns and the brain cell number. Our data clearly support E2 biosynthesis in the early brain, and that brain E2 induces neurogenesis. These peak activity patterns in the early brain occur at the time of gonad differentiation but are independent of the gonads.

}, issn = {1932-846X}, doi = {10.1002/dneu.22303}, author = {Lin, Chien-Ju and Fan-Chiang, Yi-Chun and Sylvie Dufour and Chang, Ching-Fong} } @article {5423, title = {Activation of brain steroidogenesis and neurogenesis during the gonadal differentiation in protandrous black porgy, Acanthopagrus schlegelii.}, journal = {Developmental Neurobiology}, volume = {76}, year = {2016}, pages = {121-136}, doi = {DOI: 10.1002/dneu.22303}, author = {Lin, Chien-Ju and Fran-Chiang, Y C and Sylvie Dufour and Chang, Ching-Fong} } @article {4509, title = {A comparison of techniques for studying oogenesis in the European eel Anguilla anguilla.}, journal = {J Fish Biol}, year = {2016}, month = {2016 Aug 8}, abstract = {

A multi-technique approach was used to study the changes occurring in European eel Anguilla anguilla ovaries during hormonally-induced vitellogenesis. Aside from classic techniques used to monitor the vitellogenic process, such as ovary histology, fat content analysis, sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and vitellogenin enzyme linked immunosorbent assay (ELISA), a new technique, Fourier-transform infrared (FT-IR) microspectroscopy, was used to analyse A. anguilla ovaries. The results from the different techniques provided different ways of approaching the same process. Although it is considered a time consuming approach, of all the employed techniques, histology provided the most direct evidences about vitellogenesis. SDS-PAGE and ELISA were also useful for studying vitellogenesis, whereas fat analysis cannot be used for this purpose. The FT-IR analysis provided a representative IR spectrum for each ovarian stage (previtellogenic stage, early vitellogenic stage, mid-vitellogenic stage and late vitellogenic stage), demonstrating that it is a valid method able to illustrate the distribution of the oocytes within the ovary slices. The chemical maps obtained confirmed changes in lipid concentrations and revealed their distribution within the oocytes at different maturational stages. When the results and the accuracy of the FT-IR analysis were compared with those of the traditional techniques commonly used to establish the vitellogenic stage, it became evident that FT-IR is a useful and reliable tool, with many advantages, including the fact that it requires little biological material, the costs involved are low, analysis times are short and last but not least, the fact that it offers the possibility of simultaneously analysing various biocomponents of the same oocyte.

}, issn = {1095-8649}, doi = {10.1111/jfb.13103}, author = {Mazzeo, I and Giorgini, E and Gioacchini, G and Maradonna, F and V{\'\i}lchez, M C and Sylvie Baloche and Sylvie Dufour and P{\'e}rez, L and Carnevali, O and Asturiano, J F} } @article {4507, title = {Functional characterization of eel dopamine D2 receptors and involvement in the direct inhibition of pituitary gonadotropins.}, journal = {J Neuroendocrinol}, year = {2016}, month = {2016 Jul 25}, abstract = {

In various vertebrate species, dopamine (DA) exerts an inhibitory action on reproduction. In the European eel, DA plays a pivotal role in the inhibitory control of the gonadotrope function and the blockade of puberty. In vivo studies suggested that this effect is mediated by receptors pharmacologically related to the D2-family. In the European eel, two distinct D2 receptor (D2-R) paralogous genes have been identified (D2A-R and D2B-R) and both shown to be expressed in the pituitary. We investigated the potential role of each paralog in the control of gonadotrope function in this species. Eel recombinant D2A-R or D2B-R were expressed in HEK 293 cells, with a universal Gα subunit, and receptor activation was followed by inositol phosphate production. Recombinant D2-Rs exhibited a comparable affinity for DA, but differential affinities for mammalian D2-R agonists and antagonists, supporting subtle structure/activity differences. Further, using eel pituitary cell primary cultures, the expression by gonadotrope cells of both native eel D2-R paralogs was examined by in situ hybridisation of D2A-R or D2B-R transcripts, coupled to immunofluorescence of LHβ or FSHβ. LH and to a lesser extent, FSH cells expressed both D2-R transcripts, but with a clear predominance of D2B-R. Notably, D2B- R transcripts were detected on the majority of LH cells. Accordingly, using these cultures, we showed that DA potently inhibited basal and testosterone-stimulated LHβ expression and less potently basal and activin-stimulated FSHβ expression. We also tested some D2-R antagonists in order to select the most adequate one to be used in innovative protocols for induction of eel sexual maturation. We identified eticlopride as the most potent inhibitor of DA action on basal and stimulated LH expression in vitro. Our data suggest a differential functionalisation of the duplicated receptor genes and demonstrate that mainly D2B-R is involved in the dopaminergic inhibitory control of eel gonadotrope function. This article is protected by copyright. All rights reserved.

}, issn = {1365-2826}, doi = {10.1111/jne.12411}, author = {Jolly, C and Karine Rousseau and Pr{\'e}zeau, L and Vol, C and Tomkiewicz, J and Sylvie Dufour and Pasqualini, C} } @article {4508, title = {Three nuclear and two membrane estrogen receptors in basal teleosts, Anguilla sp.: Identification, evolutionary history and differential expression regulation.}, journal = {Gen Comp Endocrinol}, volume = {235}, year = {2016}, month = {2016 Sep 1}, pages = {177-91}, abstract = {

Estrogens interact with classical intracellular nuclear receptors (ESR), and with G-coupled membrane receptors (GPER). In the eel, we identified three nuclear (ESR1, ESR2a, ESR2b) and two membrane (GPERa, GPERb) estrogen receptors. Duplicated ESR2 and GPER were also retrieved in most extant teleosts. Phylogeny and synteny analyses suggest that they result from teleost whole genome duplication (3R). In contrast to conserved 3R-duplicated ESR2 and GPER, one of 3R-duplicated ESR1 has been lost shortly after teleost emergence. Quantitative PCRs revealed that the five receptors are all widely expressed in the eel, but with differential patterns of tissue expression and regulation. ESR1 only is consistently up-regulated in vivo in female eel BPG-liver axis during induced sexual maturation, and also up-regulated in vitro by estradiol in eel hepatocyte primary cultures. This first comparative study of the five teleost estradiol receptors provides bases for future investigations on differential roles that may have contributed to the conservation of multiple estrogen receptors.

}, issn = {1095-6840}, doi = {10.1016/j.ygcen.2015.11.021}, author = {Anne-Gaelle Lafont and Karine Rousseau and Tomkiewicz, Jonna and Sylvie Dufour} } @article {3937, title = {Demonstration of the Coexistence of Duplicated LH Receptors in Teleosts, and Their Origin in Ancestral Actinopterygians.}, journal = {PLoS One}, volume = {10}, year = {2015}, month = {2015}, pages = {e0135184}, abstract = {

Pituitary gonadotropins, FSH and LH, control gonad activity in vertebrates, via binding to their respective receptors, FSHR and LHR, members of GPCR superfamily. Until recently, it was accepted that gnathostomes possess a single FSHR and a single LHR, encoded by fshr and lhcgr genes. We reinvestigated this question, focusing on vertebrate species of key-phylogenetical positions. Genome analyses supported the presence of a single fshr and a single lhcgr in chondrichthyans, and in sarcopterygians including mammals, birds, amphibians and coelacanth. In contrast, we identified a single fshr but two lhgcr in basal teleosts, the eels. We further showed the coexistence of duplicated lhgcr in other actinopterygians, including a non-teleost, the gar, and other teleosts, e.g. Mexican tetra, platyfish, or tilapia. Phylogeny and synteny analyses supported the existence in actinopterygians of two lhgcr paralogs (lhgcr1/ lhgcr2), which do not result from the teleost-specific whole-genome duplication (3R), but likely from a local gene duplication that occurred early in the actinopterygian lineage. Due to gene losses, there was no impact of 3R on the number of gonadotropin receptors in extant teleosts. Additional gene losses during teleost radiation, led to a single lhgcr (lhgcr1 or lhgcr2) in some species, e.g. medaka and zebrafish. Sequence comparison highlighted divergences in the extracellular and intracellular domains of the duplicated lhgcr, suggesting differential properties such as ligand binding and activation mechanisms. Comparison of tissue distribution in the European eel, revealed that fshr and both lhgcr transcripts are expressed in the ovary and testis, but are differentially expressed in non-gonadal tissues such as brain or eye. Differences in structure-activity relationships and tissue expression may have contributed as selective drives in the conservation of the duplicated lhgcr. This study revises the evolutionary scenario and nomenclature of gonadotropin receptors, and opens new research avenues on the roles of duplicated LHR in actinopterygians.

}, issn = {1932-6203}, doi = {10.1371/journal.pone.0135184}, author = {Gersende Maugars and Sylvie Dufour} } @article {3773, title = {The Dopaminergic Neurons Controlling Anterior Pituitary Functions: Anatomy and Ontogenesis in Zebrafish.}, journal = {Endocrinology}, year = {2015}, month = {2015 May 12}, pages = {en20151091}, abstract = {

Dopaminergic (DA) neurons located in the preoptico-hypothalamic region of the brain exert a major neuroendocrine control on reproduction, growth and homeostasis by regulating the secretion of anterior pituitary (or adenohypophysis) hormones. Here, using a retrograde tract tracing experiment, we identified the neurons playing this role in the zebrafish. The DA cells projecting directly to the anterior pituitary are localized in the most anteroventral part of the preoptic area, and we named them preoptico-hypophyseal DA (POHDA) neurons. During development, these neurons do not appear before 72 hours post fertilization (hpf) and are the last dopaminergic cell group to differentiate. We found that the number of neurons in this cell population continues to increase life-long, proportionally to the growth of the fish. BrdU incorporation analysis suggested that this increase is due to continuous neurogenesis and not due to a phenotypic change in already existing neurons. Finally, expression profiles of several genes (foxg1a, dlx2a and nr4a2a/b) were different in the POHDA compared to the adjacent suprachiasmatic DA neurons, suggesting that POHDA neurons develop as a distinct DA cell population in the preoptic area. This study offers some insights into the regional identity of the preoptic area and provides the first bases for future functional genetic studies on the development of DA neurons controlling anterior pituitary functions.

}, issn = {1945-7170}, doi = {10.1210/en.2015-1091}, author = {Fontaine, Romain and Affaticati, Pierre and Bureau, Charlotte and Colin, Ingrid and Demarque, Micha{\"e}l and Sylvie Dufour and Vernier, Philippe and Yamamoto, Kei and Pasqualini, Catherine} } @article {3774, title = {Duplicated leptin receptors in two species of eel bring new insights into the evolution of the leptin system in vertebrates.}, journal = {PLoS One}, volume = {10}, year = {2015}, month = {2015}, pages = {e0126008}, abstract = {

Since its discovery in mammals as a key-hormone in reproduction and metabolism, leptin has been identified in an increasing number of tetrapods and teleosts. Tetrapods possess only one leptin gene, while most teleosts possess two leptin genes, as a result of the teleost third whole genome duplication event (3R). Leptin acts through a specific receptor (LEPR). In the European and Japanese eels, we identified two leptin genes, and for the first time in vertebrates, two LEPR genes. Synteny analyses indicated that eel LEPRa and LEPRb result from teleost 3R. LEPRb seems to have been lost in the teleost lineage shortly after the elopomorph divergence. Quantitative PCRs revealed a wide distribution of leptins and LEPRs in the European eel, including tissues involved in metabolism and reproduction. Noticeably, leptin1 was expressed in fat tissue, while leptin2 in the liver, reflecting subfunctionalization. Four-month fasting had no impact on the expression of leptins and LEPRs in control European eels. This might be related to the remarkable adaptation of silver eel metabolism to long-term fasting throughout the reproductive oceanic migration. In contrast, sexual maturation induced differential increases in the expression of leptins and LEPRs in the BPG-liver axis. Leptin2 was strikingly upregulated in the liver, the central organ of the reproductive metabolic challenge in teleosts. LEPRs were differentially regulated during sexual maturation, which may have contributed to the conservation of the duplicated LEPRs in this species. This suggests an ancient and positive role of the leptin system in the vertebrate reproductive function. This study brings new insights on the evolutionary history of the leptin system in vertebrates. Among extant vertebrates, the eel represents a unique case of duplicated leptins and leptin receptors as a result of 3R.

}, issn = {1932-6203}, doi = {10.1371/journal.pone.0126008}, author = {Morini, Marina and Pasquier, J{\'e}r{\'e}my and Dirks, Ron and van den Thillart, Guido and Tomkiewicz, Jonna and Karine Rousseau and Sylvie Dufour and Anne-Gaelle Lafont} } @article {3936, title = {Editorial: A Comparative Survey of the RF-Amide Peptide Superfamily.}, journal = {Front Endocrinol (Lausanne)}, volume = {6}, year = {2015}, month = {2015}, pages = {120}, issn = {1664-2392}, doi = {10.3389/fendo.2015.00120}, author = {Karine Rousseau and Sylvie Dufour and Vaudry, Hubert} } @article {3862, title = {Gonadal transcriptome analysis of wild contaminated female European eels during artificial gonad maturation.}, journal = {Chemosphere}, volume = {139}, year = {2015}, month = {2015 Jul 6}, pages = {303-309}, abstract = {

Since the early 1980s, the population of European eels (Anguilla anguilla) has dramatically declined. Nowadays, the European eel is listed on the red list of threatened species (IUCN Red List) and is considered as critically endangered of extinction. Pollution is one of the putative causes for the collapse of this species. Among their possible effects, contaminants gradually accumulated in eels during their somatic growth phase (yellow eel stage) would be remobilized during their reproductive migration leading to potential toxic events in gonads. The aim of this study was to investigate the effects of organic and inorganic contaminants on the gonad development of wild female silver eels. Female silver eels from two sites with differing contamination levels were artificially matured. Transcriptomic analyses by means of a 1000 candidate gene cDNA microarray were performed on gonads after 11weeks of maturation to get insight into the mechanisms of toxicity of contaminants. The transcription levels of several genes, that were associated to the gonadosomatic index (GSI), were involved in mitotic cell division but also in gametogenesis. Genes associated to contaminants were mainly involved in the mechanisms of protection against oxidative stress, in DNA repair, in the purinergic signaling pathway and in steroidogenesis, suggesting an impairment of gonad development in eels from the polluted site. This was in agreement with the fact that eels from the reference site showed a higher gonad growth in comparison to contaminated fish.

}, issn = {1879-1298}, doi = {10.1016/j.chemosphere.2015.06.007}, author = {Baillon, Lucie and Oses, Jennifer and Pierron, Fabien and Bureau du Colombier, Sarah and Caron, Antoine and Normandeau, Eric and Lambert, Patrick and Couture, Patrice and Labadie, Pierre and Budzinski, H{\'e}l{\`e}ne and Sylvie Dufour and Bernatchez, Louis and Baudrimont, Magalie} } @article {3638, title = {Abnormal ovarian DNA methylation programming during gonad maturation in wild contaminated fish.}, journal = {Environ Sci Technol}, volume = {48}, year = {2014}, month = {2014 Oct 7}, pages = {11688-95}, abstract = {

There is increasing evidence that pollutants may cause diseases via epigenetic modifications. Epigenetic mechanisms such as DNA methylation participate in the regulation of gene transcription. Surprisingly, epigenetics research is still limited in ecotoxicology. In this study, we investigated whether chronic exposure to contaminants experienced by wild female fish (Anguilla anguilla) throughout their juvenile phase can affect the DNA methylation status of their oocytes during gonad maturation. Thus, fish were sampled in two locations presenting a low or a high contamination level. Then, fish were transferred to the laboratory and artificially matured. Before hormonal treatment, the DNA methylation levels of the genes encoding for the aromatase and the receptor of the follicle stimulating hormone were higher in contaminated fish than in fish from the clean site. For the hormone receptor, this hypermethylation was positively correlated with the contamination level of fish and was associated with a decrease in its transcription level. In addition, whereas gonad growth was associated with an increase in DNA methylation in fish from the clean site, no changes were observed in contaminated fish in response to hormonal treatment. Finally, a higher gonad growth was observed in fish from the reference site in comparison to contaminated fish.

}, issn = {1520-5851}, doi = {10.1021/es503712c}, author = {Pierron, Fabien and Bureau du Colombier, Sarah and Moffett, Audrey and Caron, Antoine and Peluhet, Laurent and Daffe, Guillemine and Lambert, Patrick and Elie, Pierre and Labadie, Pierre and Budzinski, H{\'e}l{\`e}ne and Sylvie Dufour and Couture, Patrice and Baudrimont, Magalie} } @article {3631, title = {Looking for the bird Kiss: evolutionary scenario in sauropsids.}, journal = {BMC Evol Biol}, volume = {14}, year = {2014}, month = {2014}, pages = {30}, abstract = {

BACKGROUND: The neuropeptide Kiss and its receptor KissR are key-actors in the brain control of reproduction in mammals, where they are responsible for the stimulation of the activity of GnRH neurones. Investigation in other vertebrates revealed up to 3 Kiss and 4 KissR paralogs, originating from the two rounds of whole genome duplication in early vertebrates. In contrast, the absence of Kiss and KissR has been suggested in birds, as no homologs of these genes could be found in current genomic databases. This study aims at addressing the question of the existence, from an evolutionary perspective, of the Kisspeptin system in birds. It provides the first large-scale investigation of the Kisspeptin system in the sauropsid lineage, including ophidian, chelonian, crocodilian, and avian lineages.

RESULTS: Sauropsid Kiss and KissR genes were predicted from multiple genome and transcriptome databases by TBLASTN. Phylogenetic and syntenic analyses were performed to classify predicted sauropsid Kiss and KissR genes and to re-construct the evolutionary scenarios of both gene families across the sauropsid radiation.Genome search, phylogenetic and synteny analyses, demonstrated the presence of two Kiss genes (Kiss1 and Kiss2 types) and of two KissR genes (KissR1 and KissR4 types) in the sauropsid lineage. These four genes, also present in the mammalian lineage, would have been inherited from their common amniote ancestor. In contrast, synteny analyses supported that the other Kiss and KissR paralogs are missing in sauropsids as in mammals, indicating their absence in the amniote lineage. Among sauropsids, in the avian lineage, we demonstrated the existence of a Kiss2-like gene in three bird genomes. The divergence of these avian Kiss2-like sequences from those of other vertebrates, as well as their absence in the genomes of some other birds, revealed the processes of Kiss2 gene degeneration and loss in the avian lineage.

CONCLUSION: These findings contribute to trace back the evolutionary history of the Kisspeptin system in amniotes and sauropsids, and provide the first molecular evidence of the existence and fate of a Kiss gene in birds.

}, keywords = {Amino Acid Sequence, Animals, Avian Proteins, Biological Evolution, Birds, Humans, Kisspeptins, Molecular Sequence Data, Phylogeny, Receptors, G-Protein-Coupled, Reptiles, Sequence Alignment, Synteny}, issn = {1471-2148}, doi = {10.1186/1471-2148-14-30}, author = {Pasquier, J{\'e}r{\'e}my and Anne-Gaelle Lafont and Karine Rousseau and Qu{\'e}rat, Bruno and Chemineau, Philippe and Sylvie Dufour} } @article {3211, title = {Molecular evolution of GPCRs: Kisspeptin/kisspeptin receptors.}, journal = {J. Mol. Endocrinol.}, volume = {52}, year = {2014}, pages = {101-117}, author = {Pasquier, J and Kamech, Nedia and Anne-Gaelle Lafont and H Vaudry and Karine Rousseau and Sylvie Dufour} } @article {3636, title = {Multiple thyrotropin β-subunit and thyrotropin receptor-related genes arose during vertebrate evolution.}, journal = {PLoS One}, volume = {9}, year = {2014}, month = {2014}, pages = {e111361}, abstract = {

Thyroid-stimulating hormone (TSH) is composed of a specific β subunit and an α subunit that is shared with the two pituitary gonadotropins. The three β subunits derive from a common ancestral gene through two genome duplications (1R and 2R) that took place before the radiation of vertebrates. Analysis of genomic data from phylogenetically relevant species allowed us to identify an additional Tshβ subunit-related gene that was generated through 2R. This gene, named Tshβ2, present in cartilaginous fish, little skate and elephant shark, and in early lobe-finned fish, coelacanth and lungfish, was lost in ray-finned fish and tetrapods. The absence of a second type of TSH receptor (Tshr) gene in these species suggests that both TSHs act through the same receptor. A novel Tshβ sister gene, named Tshβ3, was generated through the third genomic duplication (3R) that occurred early in the teleost lineage. Tshβ3 is present in most teleost groups but was lostin tedraodontiforms. The 3R also generated a second Tshr, named Tshrb. Interestingly, the new Tshrb was translocated from its original chromosomic position after the emergence of eels and was then maintained in its new position. Tshrb was lost in tetraodontiforms and in ostariophysians including zebrafish although the latter species have two TSHs, suggesting that TSHRb may be dispensable. The tissue distribution of duplicated Tshβs and Tshrs was studied in the European eel. The endocrine thyrotropic function in the eel would be essentially mediated by the classical Tshβ and Tshra, which are mainly expressed in the pituitary and thyroid, respectively. Tshβ3 and Tshrb showed a similar distribution pattern in the brain, pituitary, ovary and adipose tissue, suggesting a possible paracrine/autocrine mode of action in these non-thyroidal tissues. Further studies will be needed to determine the binding specificity of the two receptors and how these two TSH systems are interrelated.

}, issn = {1932-6203}, doi = {10.1371/journal.pone.0111361}, author = {Gersende Maugars and Sylvie Dufour and Cohen-Tannoudji, Jo{\"e}lle and Qu{\'e}rat, Bruno} } @article {3639, title = {Neuroendocrine gene expression reveals a decrease in dopamine D2B receptor with no changes in GnRH system during prepubertal metamorphosis of silvering in wild Japanese eel.}, journal = {Gen Comp Endocrinol}, volume = {206}, year = {2014}, month = {2014 Sep 15}, pages = {8-15}, abstract = {

Silvering is a prepubertal metamorphosis preparing the eel to the oceanic reproductive migration. A moderate gonad development occurs during this metamorphosis from the sedentary yellow stage to the migratory silver stage. The aim of this study was to elucidate the molecular aspects of various endocrine parameters of BPG axis at different ovarian developmental stages in wild yellow and silver female Japanese eels. The GSI of the sampled female eels ranged between 0.18 and 2.3\%, corresponding to yellow, pre-silver and silver stages. Gonad histology showed changes from previtellogenic oocytes in yellow eels to early vitellogenic oocytes in silver eels. Both serum E2 and T concentrations significantly increased with ovarian development indicating a significant activation of steroidogenesis during silvering. In agreement with previous studies, significant increases in pituitary gonadotropin beta subunits FSH-β and LH-β transcripts were also measured by qPCR, supporting that the activation of pituitary gonadotropin expression is likely responsible for the significant ovarian development observed during silvering. We investigated for the first time the possible brain neuroendocrine mechanisms involved in the activation of the pituitary gonadotropic function during silvering. By analyzing the expression of genes representative of the stimulatory GnRH control and the inhibitory dopaminergic control. The transcript levels of mGnRH and the three GnRH receptors did not change in the brain and pituitary between yellow and silver stages, suggesting that gene expression of the GnRH system is not significantly activated during silvering. The brain transcript levels of tyrosine hydroxylase, limiting enzyme of DA synthesis did not change during silvering, indicating that the DA synthesis activity was maintained. In contrast, a significant decrease in DA-D2B receptor expression in the forebrain and pituitary was observed, with no changes in DA-D2A receptor. The decrease in the pituitary expression of DA-D2BR during silvering would allow a reduced inhibitory effect of DA. We may raise the hypothesis that this regulation of D2BR gene expression is one of the neuroendocrine mechanisms involved in the slight activation of the pituitary gonadotropin and gonadal activity that occur at silvering.

}, keywords = {Animals, Cells, Cultured, Dopamine, Eels, Female, Follicle Stimulating Hormone, beta Subunit, Gene Expression Regulation, Gonadotropin-Releasing Hormone, Immunoblotting, Immunoenzyme Techniques, Luteinizing Hormone, beta Subunit, Metamorphosis, Biological, Neurosecretory Systems, Oocytes, Ovary, Real-Time Polymerase Chain Reaction, Receptors, Dopamine D2, Reproduction, Reverse Transcriptase Polymerase Chain Reaction, RNA, Messenger, Sexual Maturation, Skin Pigmentation}, issn = {1095-6840}, doi = {10.1016/j.ygcen.2014.08.001}, author = {Jeng, Shan-Ru and Wen-Shiun Yueh and Pen, Yi-Ting and Lee, Yan-Horn and Chen, Guan-Ru and Sylvie Dufour and Chang, Ching-Fong} } @article {4512, title = {Temperature modulates the progression of vitellogenesis in the European eel}, journal = {Aquaculture}, volume = {434}, year = {2014}, pages = {38-47}, author = {Mazzeo, I and Penaranda, David S and Gallego, Victor and Sylvie Baloche and Nourizadeh-Lillabadi, R and Tveiten, Helge and Sylvie Dufour and Asturiano, Juan F and Weltzien, Finn-Arne and Perez, Luz} }