There is growing evidence that estrogens play important roles in both normal and xenoestrogen disrupted testis physiology. However, the mechanisms and signaling pathways involved, in particular in fish, are largely unknown. We have used suppression subtractive hybridization to isolate 152 candidate estrogen-responsive genes in the testis of male estradiol (E2)-treated sea bream (Sparus aurata). The E2 up-regulation of some of the genes (e.g., choriogenin L and H, vitellogenin I and II, apolipoprotein A-I, fibrinogen beta and gamma, and thyroid receptor interacting protein 4) was confirmed by reverse transcriptase polymerase chain reaction in fish treated with 0.1-10 mg/kg E2. Many of these genes are typical E2-induced genes in liver, and this is the first report of its up regulation with E2 in testis. Moreover, low levels of expression were also found for nontreated fish. Hepatic differential expression for these genes was also confirmed, although, contrary to testis, fibrinogen beta, and gamma were downregulated. The possible significance of these findings in normal testis physiology and in endocrine disruption is discussed.

In the present study cDNA clones representing two slow skeletal muscle troponin T genes (sTnT1sb and sTnT2sb) in the sea bream (Sparus auratus), an important aquaculture species, were isolated and characterised. A third, intronless, TnT gene (iTnTsb), which is an apparent orthologue of a previously described zebrafish TnT, was also isolated. In adult sea bream sTnT expression was restricted to red muscle and, using northern blotting, a single low abundance transcript was identified for sTnT1sb (1260 nucleotides) and a single high abundance transcript was identified for sTnT2sb (1000 nucleotides). In contrast, iTnTsb is predominantly expressed in adult fast muscle. All three TnT genes are also expressed during larval development. Phylogenetic analysis of sea bream sTnT proteins to identify maximum parsimony showed that iTnTsb, sTnT1sb and sTnT2sb each cluster in independent groups. sTnT1sb clustered with other vertebrate sTnTs, while sTnT2 clustered with a group of fish specific sequences (from Fugu rubripes, Oryzia latipes and Salmo trutta). The teleost sTnT2 and iTnT each constitute new, apparently teleost specific, TnT groups. Analysis of the corresponding Fugu scaffold indicates that sTnT2sb is encoded by a gene with twelve exons. The two sTnT cDNAs isolated in sea bream probably arose by duplication of an ancestral gene, and iTnT by reverse transcription. It remains to be established if the encoded proteins have different structural and mechanistic roles in fish muscle.

Sox (SRY-related genes containing a HMG box) genes encode a family of transcription factors that are involved in a variety of developmental processes including sex determination. Twenty Sox genes are present in the genomes of humans and mice, but far less is known about the Sox gene family in other vertebrate types. We have obtained clones representing the HMG boxes of twelve Sox genes from European sea bass (Dicentrarchus labrax), a fish species whose farming is complicated by a heavily skewed sex ratio, with between 70% and 99% of offspring typically being male. The cloned Sox genes are members of the SoxB, SoxC, SoxE and SoxF groups. Sequence analysis shows that some of the clones represent genes duplicated in sea bass with respect to the mammalian Sox gene family.

Thyroid hormones have been implicated as important regulators of teleost development. To gain a better understanding of the potential roles of the thyroid system in salmonids a genomic clone which encoded rainbow trout TR-alpha was isolated. This clone exhibited highest amino acid identity to Japanese flounder TR-alphaB (94%) and zebrafish TR-alpha1 (94%). Oligonucleotides were designed against the rainbow trout sequence and the complete coding region of Atlantic salmon TR-alpha was isolated by RACE-PCR. The Atlantic salmon sequence exhibited highest amino acid identity to rainbow trout TR-alpha (98%), Japanese flounder TR-alphaB (93%), and zebrafish TR-alpha1 (90%). Atlantic salmon TR-alpha exhibited the classic modular structure associated with members of the nuclear receptor superfamily and consisted of a divergent A/B domain while the DNA and ligand-binding domains were highly conserved to other teleost TR proteins. Temporal expression from the rainbow trout TR-alpha gene was monitored by semiquantitative RT-PCR at selected stages during rainbow trout embryonic and larval development. High levels of maternal transcripts were present at cleavage (Stage 6) which were rapidly degraded by gastrulation (Stage 13). Low levels of TR-alpha expression were then detected during organogenesis (Stages 20, 24, 26, 29, and 31). A peak in mRNA levels was observed at hatch (Stage 32) after which levels rose in a gradual manner during larval development (Stages 33, 34, 35, and 36) to reach maximal values at first feeding (Stage 37). These results suggest that the thyroid axis is functional and that embryonic and larval rainbow trout are at least capable of responding to thyroid hormones. These observations implicate the thyroid system as being an important regulator of salmonid development.

The thyroid hormones (THs), thyroxine (T(4)) and triiodothyronine (T(3)) are products of the thyroid gland in all vertebrates. Their role in early development and metamorphosis is well established in mammals and amphibians, respectively, and recently several studies in fish have highlighted the importance of THs during flatfish metamorphosis. THs are present in high quantities in fish eggs and are presumably of maternal origin. During embryogenesis the concentration of T(4) and T(3) in the eggs decrease until endogenous production starts. Thyroid hormone receptors (TR) have been isolated from several teleosts and in common with tetrapods two receptor isoforms have been identified, TR alpha and TR beta. Both the receptors are expressed in early embryos and larvae of the Japanese flounder (Paralichthys olivaceus), zebrafish (Danio rerio) and seabream (Sparus aurata) although a different temporal pattern is apparent. The role of THs and TRs in fish embryogenesis, larval development and during metamorphosis will be discussed.

A clone encoding thyroid hormone receptor-beta (TR-beta) was isolated from a sea bream (Sparus aurata) ovary cDNA library. Sea bream (sb)TR-beta is closely related to its counterparts from other vertebrates and, like them, preferentially binds T3 rather than T4. However, the putative sbTR-beta protein contains a nine-amino-acid insert that is also present in the corresponding proteins from flounder and salmon but absent in TR-betas from zebrafish and terrestrial vertebrates. Semiquantitative RT-PCR analysis showed that sbTR-beta transcripts begin to accumulate during gastrulation and increase markedly in quantity up to the period around hatch (ca. 40 h postfertilization) before declining slightly. In adult tissues, TR-beta mRNA was present in approximately equal quantities in heart, intestine, brain, kidney, skeletal muscle, liver, and gill. The significance of the relatively strong expression of TR-beta during sea bream embryogenesis is discussed.

A full-length clone of the aldolase B gene has been isolated from a cDNA library constructed from liver of Atlantic salmon (Salmo salar). Sequencing showed that the clone encodes a typical aldolase B, possessing a number of amino acid residues which are seen in aldolase B, but not in other aldolase isoforms. RT-PCR analysis showed that the gene is expressed in liver, kidney and intestine as expected. However, in contrast to mammalian and avian aldolase B, expression was also found in a number of other tissues. Levels of aldolase B mRNA in liver and kidney were not significantly altered during smoltification, the transformation of freshwater-dwelling salmon (parr) into saltwater-adapted salmon (smolts).

We report here the cloning, characterisation and developmental expression profile of the Xenopus laevis CCAAT-enhancer binding protein β (xC/EBPβ) gene. The protein synthesised from the xC/EBPβ gene interacts specifically with a C/EBP-recognition sequence and acts as a transcriptional activator. Several conserved regions are present in the xC/EBPβ sequence, including the basic region, leucine zipper, activation domains, three in-frame AUG codons, and a consensus site for mitogen activated protein kinase. The corresponding mRNA is present at high levels in the kidney, liver, lung, muscle and adipose tissue, and at low levels in the ovary, brain and heart. Although the xC/EBPβ mRNA and protein are present throughout embryogenesis, there is a biphasic increase in their expression levels during development. Whole-mount in situ hybridisation shows a restricted spatial expression profile of the xC/EBPβ gene during early embryogenesis, with transcripts present around the blastopore lip and in the endodermal cells at the mid-gastrula stage, and, the whole dorsal side at the neurula and early tailbud stage. The expression domain becomes almost ubiquitous during later embryonic development, and includes the brain, spinal cord, somites and regions that give rise to the liver and the heart.

Annals of the New York Academy of SciencesVolume 839, Issue 1 p. 610-611 Expression of Thyroid Hormone Receptor during Early Development of the Sea Bream (Sparus aurata)a LYNDA LLEWELLYN, LYNDA LLEWELLYN School of Molecular and Medical Biosciences, University of Wales, PO Box 911, Cardiff CF1 3US, United Kingdom School of Pure and Applied Biology, University of Wales, PO Box 915, Cardiff CF1 3TL, United KingdomSearch for more papers by this authorVIMI P. RAMSURN, VIMI P. RAMSURN School of Molecular and Medical Biosciences, University of Wales, PO Box 911, Cardiff CF1 3US, United Kingdom School of Pure and Applied Biology, University of Wales, PO Box 915, Cardiff CF1 3TL, United KingdomSearch for more papers by this authorGLEN E. SWEENEY, GLEN E. SWEENEY School of Molecular and Medical Biosciences, University of Wales, PO Box 911, Cardiff CF1 3US, United KingdomSearch for more papers by this authorTREVOR WIGHAM, TREVOR WIGHAM School of Molecular and Medical Biosciences, University of Wales, PO Box 911, Cardiff CF1 3US, United KingdomSearch for more papers by this authorDEBORAH M. POWER, DEBORAH M. POWER CCMAR, Unidade de Ciencias e Tecnologias Agrarias, Universidade do Algarve, Campus de Gambelas, Faro 8000, PortugalSearch for more papers by this author LYNDA LLEWELLYN, LYNDA LLEWELLYN School of Molecular and Medical Biosciences, University of Wales, PO Box 911, Cardiff CF1 3US, United Kingdom School of Pure and Applied Biology, University of Wales, PO Box 915, Cardiff CF1 3TL, United KingdomSearch for more papers by this authorVIMI P. RAMSURN, VIMI P. RAMSURN School of Molecular and Medical Biosciences, University of Wales, PO Box 911, Cardiff CF1 3US, United Kingdom School of Pure and Applied Biology, University of Wales, PO Box 915, Cardiff CF1 3TL, United KingdomSearch for more papers by this authorGLEN E. SWEENEY, GLEN E. SWEENEY School of Molecular and Medical Biosciences, University of Wales, PO Box 911, Cardiff CF1 3US, United KingdomSearch for more papers by this authorTREVOR WIGHAM, TREVOR WIGHAM School of Molecular and Medical Biosciences, University of Wales, PO Box 911, Cardiff CF1 3US, United KingdomSearch for more papers by this authorDEBORAH M. POWER, DEBORAH M. POWER CCMAR, Unidade de Ciencias e Tecnologias Agrarias, Universidade do Algarve, Campus de Gambelas, Faro 8000, PortugalSearch for more papers by this author First published: 07 February 2006 https://doi.org/10.1111/j.1749-6632.1998.tb10893.xCitations: 9 a This work was funded by a European Union grant. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat REFERENCES 1 Brown C. L., Sullivan C.V., Bern H.A. & Dickhoff W.W. 1987. Trans. Am. Fish Soc. Symp. 2: 144–150. 2 Yamano K., Takano-Ohmuro H., Obinata T. & Inui Y. 1994. Gen. Comp. Endocrinol. 93: 321–326. Citing Literature Volume839, Issue1TRENDS IN COMPARATIVE ENDOCRINOLOGY AND NEUROBIOLOGY: FROM MOLECULAR TO INTEGRATIVE BIOLOGYMay 1998Pages 610-611 ReferencesRelatedInformation

A full length cDNA clone representing apolipoprotein A-I was isolated from a sea bream (Sparus aurata) liver library. The clone encodes a 261 amino acid protein which shows highest amino acid identity (38%) with salmon apolipoprotein A-I. Northern blot analysis showed strong expression of a 1.4 kb transcript in liver with lower expression in intestine. Expression of apolipoprotein A-I in intestine was markedly reduced by treatment with triiodothyronine (T3).

Conference Article| November 01 1997 117 Characterisation of a Xenopus 14-3-3 gene STAVROULA KOUSTENI; STAVROULA KOUSTENI 1School of Molecular and Medical Biosciences, University of Wales, Cardiff, Museum Avenue, Cardiff CF1 3US, U.K. Search for other works by this author on: This Site PubMed Google Scholar FERAY TURA KOCKAR; FERAY TURA KOCKAR 1School of Molecular and Medical Biosciences, University of Wales, Cardiff, Museum Avenue, Cardiff CF1 3US, U.K. Search for other works by this author on: This Site PubMed Google Scholar GLEN E. SWEENEY; GLEN E. SWEENEY 1School of Molecular and Medical Biosciences, University of Wales, Cardiff, Museum Avenue, Cardiff CF1 3US, U.K. Search for other works by this author on: This Site PubMed Google Scholar DIPAK P. RAMJI DIPAK P. RAMJI 1School of Molecular and Medical Biosciences, University of Wales, Cardiff, Museum Avenue, Cardiff CF1 3US, U.K. Search for other works by this author on: This Site PubMed Google Scholar Author and article information Publisher: Portland Press Ltd Online ISSN: 1470-8752 Print ISSN: 0300-5127 © 1997 Biochemical Society1997 Biochem Soc Trans (1997) 25 (4): S649. https://doi.org/10.1042/bst025s649 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Cite Icon Cite Get Permissions Citation STAVROULA KOUSTENI, FERAY TURA KOCKAR, GLEN E. SWEENEY, DIPAK P. RAMJI; 117 Characterisation of a Xenopus 14-3-3 gene. Biochem Soc Trans 1 November 1997; 25 (4): S649. doi: https://doi.org/10.1042/bst025s649 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1997 Biochemical Society1997 Article PDF first page preview Close Modal You do not currently have access to this content.

We report the cloning and characterisation of a cDNA that encodes a novel member of the Xenopus laevis 14-3-3 protein family. Sequence analysis reveals that the cDNA-encoded protein shares 84% identity with the rat, human or sheep 14-3-3ζ isoform, and between 66% and 77% identity with bovine, human or rat β, bovine γ, human τ, Drosophila 14-3-3 and a previously isolated Xenopus member. The corresponding mRNA is present in all adult tissues examined with the highest levels in the brain. Although the gene is expressed throughout embryogenesis, higher levels of mRNA accumulate after gastrulation. Whole-mount in situ hybridisation on tailbud stage embryo reveals strong expression of the gene in the head, optic vesicles, spinal cord and branchial arches with weaker expression in the somites. In addition, expression along the notochord is observed at stage 45 (tadpole). This spatial and temporal expression profile along with recent studies implicating the importance of 14-3-3 proteins in the regulation of signal transduction pathways argues for a key role of this isoform in embryonic development.

A full-length cDNA clone encoding beta-actin (beta-actin) was isolated from a sea bream (Sparus aurata) liver cDNA library. Sequencing of this clone reveals an open reading frame encoding a 375 amino acid protein that shares a high degree of conservation to other known actins. The sea bream beta-actin sequence showed 98% identity to carp and human beta-actin and 95% and 94% identity to sea squirt and Dictyostelium cytoplasmic actins, respectively.

COUP-TFs (Chicken Ovalbumin Upstream Promoter Transcription Factors) have been proposed to be negative regulators of retinoid receptor-mediated transcriptional activation. In a previous paper we reported the cloning of a Xenopus (x) COUP-TF (Matharu, P.J. and Sweeney, G.E. (1992) Biochim. Biophys. Acta 1129, 331-334). Here we describe the cloning of a second xCOUP-TF. Amino acid sequence comparison between these two Xenopus COUP-TFs revealed a high level of similarity. Extensive amino acid sequence conservation was found among all Drosophila, Xenopus, zebrafish and mammalian COUP-TF genes examined. Phylogenetic tree analyses indicate that the vertebrate COUP-TFs fall into three classes. The two Xenopus COUP-TF genes show similar temporal expression patterns: both are expressed from the end of gastrulation. In situ hybridization studies reveal complex expression patterns in the developing central nervous system (CNS), besides expression in the eye and in some mesodermal tissues. Retinoic acid (RA) treatment enhances xCOUP-TF-A expression in neurula stage embryos, whereas the expression of xCOUP-TF-B is inhibited during the same developmental period. The strictly conserved amino acid sequences and the strong similarities between the expression patterns of the two different xCOUP-TFs on the one hand, and other vertebrate COUP-TF homologues on the other, make it likely that COUP-TFs have a conserved role in patterning the nervous system.

To investigate the factors involved in the control of metallothionein (MT) expression in fish, genomic clones encoding the MTs from the Cd-tolerant fish (pike and stone loach) were isolated. Sequencing revealed putative metal regulatory elements (MREs) in the 5′-regions of both MT genes. Comparison of their composition and location showed little distinction between different fish species. However, although high overall homology exists between fish MTs and their mammalian counterparts, the 5′-regions of the fish genes are distinct, not only in the organisation of their MREs but also in the absence of other transcription factor binding sites.

A full length cDNA clone representing an aldolase mRNA was isolated from a sea bream (Sparus aurata) liver cDNA library. Sequencing of this clone revealed it to encode a 364 amino acid protein with 74% amino acid identity to human aldolase B and slightly lower similarity to human aldolase A and C. In view of the sequence data and of Northern blot analysis showing strong expression of a 1.6 kb transcript in liver it was concluded that the cloned gene represents aldolase B. This clone represents the first aldolase gene to be sequenced from any fish species thus providing new data on the evolution of the vertebrate aldolase gene family.

Conference Article| August 01 1994 A Xenopus homologue of the NGFI-B orphan receptor TRUDI S. SMITH; TRUDI S. SMITH 1Department of Biochemistry, P. O. Box 903, University of Wales, Cardiff CF1 1ST Search for other works by this author on: This Site PubMed Google Scholar GLEN E. SWEENEY GLEN E. SWEENEY 1Department of Biochemistry, P. O. Box 903, University of Wales, Cardiff CF1 1ST Search for other works by this author on: This Site PubMed Google Scholar Biochem Soc Trans (1994) 22 (3): 250S. https://doi.org/10.1042/bst022250s Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Cite Icon Cite Get Permissions Citation TRUDI S. SMITH, GLEN E. SWEENEY; A Xenopus homologue of the NGFI-B orphan receptor. Biochem Soc Trans 1 August 1994; 22 (3): 250S. doi: https://doi.org/10.1042/bst022250s Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1994 Biochemical Society1994 Article PDF first page preview Close Modal You do not currently have access to this content.

Conference Article| August 01 1994 Expression of the XCOUP transcription factor in Xenopus laevls PHILIP J. MATHARU; PHILIP J. MATHARU 1Department of Biochemistry, P. O. Box 903, University of Wales, Cardiff CF1 1ST Search for other works by this author on: This Site PubMed Google Scholar GLEN E. SWEENEY GLEN E. SWEENEY 1Department of Biochemistry, P. O. Box 903, University of Wales, Cardiff CF1 1ST Search for other works by this author on: This Site PubMed Google Scholar Author and article information Publisher: Portland Press Ltd Online ISSN: 1470-8752 Print ISSN: 0300-5127 © 1994 Biochemical Society1994 Biochem Soc Trans (1994) 22 (3): 251S. https://doi.org/10.1042/bst022251s Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Cite Icon Cite Get Permissions Citation PHILIP J. MATHARU, GLEN E. SWEENEY; Expression of the XCOUP transcription factor in Xenopus laevls. Biochem Soc Trans 1 August 1994; 22 (3): 251S. doi: https://doi.org/10.1042/bst022251s Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1994 Biochemical Society1994 Article PDF first page preview Close Modal You do not currently have access to this content.

Conference Article| August 01 1994 Sequence analysis of the 5′ flanking sequence of ovine Lipoprotein Lipase (LPL) CARL P. VOLPE; CARL P. VOLPE 1Department of Biochemistry, University of Wales, Cardiff, PO Box 903. Cardiff, CF1 1ST, U.K. Search for other works by this author on: This Site PubMed Google Scholar MICHAEL C. BARBER; MICHAEL C. BARBER *Hannah Research Institute, Ayr, Scotland, KA6 5HL, U.K. Search for other works by this author on: This Site PubMed Google Scholar MAUREEN T. TRAVERS; MAUREEN T. TRAVERS *Hannah Research Institute, Ayr, Scotland, KA6 5HL, U.K. Search for other works by this author on: This Site PubMed Google Scholar GLEN E. SWEENEY; GLEN E. SWEENEY 1Department of Biochemistry, University of Wales, Cardiff, PO Box 903. Cardiff, CF1 1ST, U.K. Search for other works by this author on: This Site PubMed Google Scholar DAVID J. FLINT; DAVID J. FLINT *Hannah Research Institute, Ayr, Scotland, KA6 5HL, U.K. Search for other works by this author on: This Site PubMed Google Scholar ANTHONY CRYER ANTHONY CRYER 1Department of Biochemistry, University of Wales, Cardiff, PO Box 903. Cardiff, CF1 1ST, U.K. Search for other works by this author on: This Site PubMed Google Scholar Author and article information Publisher: Portland Press Ltd Online ISSN: 1470-8752 Print ISSN: 0300-5127 © 1994 Biochemical Society1994 Biochem Soc Trans (1994) 22 (3): 246S. https://doi.org/10.1042/bst022246s Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Cite Icon Cite Get Permissions Citation CARL P. VOLPE, MICHAEL C. BARBER, MAUREEN T. TRAVERS, GLEN E. SWEENEY, DAVID J. FLINT, ANTHONY CRYER; Sequence analysis of the 5′ flanking sequence of ovine Lipoprotein Lipase (LPL). Biochem Soc Trans 1 August 1994; 22 (3): 246S. doi: https://doi.org/10.1042/bst022246s Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1994 Biochemical Society1994 Article PDF first page preview Close Modal You do not currently have access to this content.