Dr Glen Sweeney

Research

Our work concerns aspects of the molecular biology of farmed fish species. We have two main interests.

The nature and regulation of life cycle transitions in fish

All fish species go through a transition that converts the larva which emerges following hatching of an egg, into a juvenile that simply needs to grow to attain the adult phenotype. The most dramatic manifestation of the larval-juvenile transition is seen in flatfish metamorphosis, where there are dramatic morphological changes and a loss of external bilateral symmetry. We are studying metamorphosis in a major cultured flatfish species, the Atlantic halibut (Hippoglossus hippoglossus). Subtractive hybridisation is being used to identify genes that become activated during metamorphosis. Additionally the role of the endocrine system in metamorphosis is being investigated. In particular we are investigated the role of thyroid hormones, and thyroid hormone receptors in promoting halibut metamorphosis and the larval-juvenile transition in a non-metamorphic fish species, the sea bream Sparus aurata.

We are also conducting research into smoltification — the process by which freshwater salmon become adapted for life in salt water prior to their migration from river to sea. Subtractive hybridisation is being used to isolated genes that show differential expression during metamorphosis, and we have also cloned thyroid homrone receptors from salmon since thyroid hormones have a role in regulating smoltification.

Sex determination in fish

Unlike the simple XY/XX chromosomal sex-determining system of mammals, fish use a range of different strategies to determine sex. Some fish species have chromosomal sex determining systems analogous to those of mammals (XX/XY) or birds (ZZ/ZW), but in other species the are no morphologically distinct sex chromosomes, with environmental factors taking the lead role in sex determination. We are studying the role of candidate sex determining genes, particularly WT-1, and various members of the sox gene family, in sex determination in the European sea bass (Dicentrarchus labrax). Sea bass is of great interested because of the heavily skewed sex ratios (approx. 90% of offspiring are male), that are encountered on sea bass farms.

Grants

Recent Funding for research in my lab has come from the EU and the BBSRC.

Collaborations

• Dr D. Power, Centre for Marine Sciences, University of the Algarve, Portugal
• Professor A. Canario, Centre for Marine Sciences, University of the Algarve, Portugal
• Professor B. Th. Bjornsson, Department of Zoophysiology, University of Goteborg, Sweden.
• Dr K. Pittman, Department of Fisheries and Marine Biology, University of Bergen, 5020 Bergen, Norway
• Ms H. Smaradottir, Fiskeldi Eyjafjardar Ltd. Glerargata 34, Akureyri, Iceland.
• Dr S. Zanuy, Instituto de Acuicultura de Torre de la Sal (CSIC), Castellon, Spain
• Dr C. Mylonas, Institute of Marine Biology of Crete, Iraklion, Crete, Greece.
• Dr F. Piferrer, Institute of Marine Sciences, Barcelona, Spain
• Dr A. Tandler, National Center for Mariculture, Eilat, Israel.
• Professor A. J. Teale, Institute of Aquaculture, University of Stirling
• Professor C. Secombes, Department of Zoology, University of Aberdeen
• Dr S. Martin, Department of Zoology, University of Aberdeen
• Professor D. Houlihan, Department of Zoology, University of Aberdeen

Publications

2012

• Campinho, M. A., Galay-Burgos, M., Silva, N., Costa, R. A., Alves, R. N., Sweeney, G. E. and Power, D. M. 2012. Molecular and cellular changes in skin and muscle during metamorphosis of Atlantic halibut (Hippoglossus hippoglossus) are accompanied by changes in deiodinases expression. Cell and Tissue Research 350(2), pp. 333-346.   (10.1007/s00441-012-1473-x)
• Navarro-Martín, L., Galay-Burgos, M., Piferrer, F. and Sweeney, G. E. 2012. Characterisation and expression during sex differentiation of Sox19 from the sea bass Dicentrarchus labrax. Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 163(3-4), pp. 316-323.   (10.1016/j.cbpb.2012.08.004)

2010

• Campinho, M. A., Galay-Burgos, M., Sweeney, G. E. and Power, D. . M. 2010. Coordination of deiodinase and thyroid hormone receptor expression during the larval to juvenile transition in sea bream (Sparus aurata, Linnaeus). General and Comparative Endocrinology 165(2), pp. 181-194.   (10.1016/j.ygcen.2009.06.020)

2009

• Seear, P. J., Carmichael, S. N., Talbot, R., Taggart, J. B., Bron, J. E. and Sweeney, G. E. 2009. Differential gene expression during smoltification of Atlantic salmon (Salmo salar L.): a first large-scale microarray study. Marine Biotechnology 12(2), pp. 126-140.   (10.1007/s10126-009-9218-x)
• Navarro-Martín, L., Galay-Burgos, M., Sweeney, G. E. and Piferrer, F. 2009. Different sox17 transcripts during sex differentiation in sea bass, Dicentrarchus labrax. Molecular and Cellular Endocrinology 299(2), pp. 240-251.   (10.1016/j.mce.2008.11.013)

2008

• Power, D. M. et al. 2008. The Molecular and endocrine basis of flatfish metamorphosis. Reviews in Fisheries Science 16(sup 1), pp. 95-111.   (10.1080/10641260802325377)
• Taggart, J. B. et al. 2008. A description of the origins, design and performance of the TRAITS–SGP Atlantic salmon Salmo salar L. cDNA microarray. Journal of Fish Biology 72(9), pp. 2071-2094.   (10.1111/j.1095-8649.2008.01876.x)
• Galay-Burgos, M., Power, D. M., Llewellyn, L. and Sweeney, G. E. 2008. Thyroid hormone receptor expression during metamorphosis of Atlantic halibut (Hippoglossus hippoglossus). Molecular and Cellular Endocrinology 281(1-2), pp. 56-63.   (10.1016/j.mce.2007.10.009)

2007

• Seear, P. J. and Sweeney, G. E. 2007. Stability of RNA isolated from post-mortem tissues of Atlantic salmon (Salmo salar L.).   Fish Physiology and Biochemistry 34(1), pp. 19-24. (10.1007/s10695-007-9141-x)
• Martin, S. A. M. et al. 2007. Interferon type I and type II responses in an Atlantic salmon (Salmo salar) SHK-1 cell line by the salmon TRAITS/SGP microarray. Physiological genomics 32(1), pp. 33-44.   (10.1152/physiolgenomics.00064.2007)
• Campinho, M. A., Silva, N., Nowell, M. A., Llewellyn, L., Sweeney, G. E. and Power, D. M. 2007. Troponin T isoform expression is modulated during Atlantic Halibut metamorphosis. BMC Developmental Biology 7(1), article number: 71.   (10.1186/1471-213X-7-71)
• Hildahl, J., Galay-Burgos, M., Sweeney, G. E., Einarsdóttir, I. E. and Björnsson, B. T. 2007. Identification of two isoforms of Atlantic halibut insulin-like growth factor-I receptor genes and quantitative gene expression during metamorphosis. Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 147(3), pp. 395-401.   (10.1016/j.cbpb.2007.02.006)
• Rocha, A., Gómez, A., Galay-Burgos, M., Zanuy, S., Sweeney, G. E. and Carrillo, M. 2007. Molecular characterization and seasonal changes in gonadal expression of a thyrotropin receptor in the European sea bass. General and Comparative Endocrinology 152(1), pp. 89-101.   (10.1016/j.ygcen.2007.03.001)
• Hildahl, J., Sweeney, G. E., Galay-Burgos, M., Einarsdóttir, I. E. and Björnsson, B. T. 2007. Cloning of Atlantic halibut growth hormone receptor genes and quantitative gene expression during metamorphosis. General and Comparative Endocrinology 151(2), pp. 143-152.   (10.1016/j.ygcen.2006.10.003)

2006

• Campinho, M. A., Silva, N., Sweeney, G. E. and Power, D. M. 2006. Molecular, cellular and histological changes in skin from a larval to an adult phenotype during bony fish metamorphosis. Cell and Tissue Research 327(2), pp. 267-284.   (10.1007/s00441-006-0262-9)
• Campinho, M. A., Sweeney, G. E. and Power, D. M. 2006. Regulation of troponin T expression during muscle development in sea bream Sparus auratus Linnaeus: the potential role of thyroid hormones. Journal of Experimental Biology 209(23), pp. 4751-4767.   (10.1242/jeb.02555)
• Galay-Burgos, M., Gealy, E. C., Navarro-Martín, L., Piferrer, F., Zanuy, S. and Sweeney, G. E. 2006. Cloning of the promoter from the gonadal aromatase gene of the European sea bass and identification of single nucleotide polymorphisms. Comparative Biochemistry and Physiology A-Molecular & Integrative Physiology 145(1), pp. 47-53.   (10.1016/j.cbpa.2006.04.028)
• Pinto, P. I. S., Teodósio, H. R., Galay-Burgos, M., Power, D. M., Sweeney, G. E. and Canário, A. V. M. 2006. Identification of estrogen-responsive genes in the testis of sea bream (Sparus auratus) using suppression subtractive hybridization. Molecular Reproduction and Development 73(3), pp. 318-329.   (10.1002/mrd.20402)

2005

• Benedet, S., Johansson, V., Sweeney, G. E., Galay-Burgos, M. and Björnsson, B. T. 2005. Cloning of two Atlantic salmon growth hormone receptor isoforms and in vitro ligand-binding response. Fish Physiology and Biochemistry 31(4), pp. 315-329.   (10.1007/s10695-005-2524-y)
• Campinho, M. A., Power, D. M. and Sweeney, G. E. 2005. Identification and analysis of teleost slow muscle troponin T (sTnT) and intronless TnT genes. Gene 361, pp. 67-79.   (10.1016/j.gene.2005.07.003)
• Campinho, M. A., Power, D. M. and Sweeney, G. E. 2005. Isolation and identification of two slow Troponin T genes in the Sparus aurata: In Silico comparative genomic analysis with Fugu rubripes. Archiv fur Tierzucht 48(SI), pp. 77-78.  

2004

• Galay-Burgos, M., Llewellyn, L., Mylonas, C. C., Canario, A. V. M., Zanuy, S. and Sweeney, G. E. 2004. Analysis of the Sox gene family in the European sea bass (Dicentrarchus labrax). Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 137(2), pp. 279-284.   (10.1016/j.cbpc.2003.12.002)

2002

• Jones, I., Rogers, S. A., Kille, P. and Sweeney, G. E. 2002. Molecular cloning and expression of thyroid hormone receptor alpha during salmonid development. General and Comparative Endocrinology 125(2), pp. 226-235.   (10.1006/gcen.2001.7745)

2001

• Jones, I., Kille, P. and Sweeney, G. E. 2001. Cadmium delays growth hormone expression during rainbow trout development. Journal of Fish Biology 59(4), pp. 1015-1022.   (10.1006/JFBI.2001.1718)
• Power, D. M. et al. 2001. Thyroid hormones in growth and development of fish. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology 130(4), pp. 447-459.   (10.1016/S1532-0456(01)00271-X)
• Nowell, M. A., Power, D. M., Canario, A. V. M., Llewellyn, L. and Sweeney, G. E. 2001. Characterization of a sea bream (Sparus aurata) thyroid hormone receptor-β clone expressed during embryonic and larval development. General and Comparative Endocrinology 123(1), pp. 80-89.   (10.1006/gcen.2001.7649)

2000

• Rogers, S. A., Llewellyn, L., Wigham, T. and Sweeney, G. E. 2000. Cloning of the Atlantic salmon (Salmo salar) estrogen receptor-α gene. Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 125(3), pp. 379-385.   (10.1016/S0305-0491(99)00184-4)
• Nowell, M. A., DM, P., PM, G., L, L., V, R., T, W. and Sweeney, G. E. 2000. Cloning and expression of an elongation factor-1a in sea bream (Sparus aurata) larvae and adult tissue. Marine Biotechnology 2(2), pp. 173-179.   (10.1007/s101269900022)

1998

• Llewellyn, L., Sweeney, G. E., Ramsurn, V. P., Rogers, S. A. and Wigham, T. 1998. Cloning and unusual expression profile of the aldolase B gene from Atlantic salmon. Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression 1443(3), pp. 375-380.   (10.1016/S0167-4781(98)00229-2)
• Llewellyn, L., Ramsurn, V. P., Wigham, T., Sweeney, G. E. and Power, D. M. 1998. Cloning, characterisation and expression of the apolipoprotein A-I gene in the sea bream (Sparus aurata). Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression 1442(2-3), pp. 399-404.   (10.1016/S0167-4781(98)00171-7)
• Kousteni, S., Kockar, F. T., Sweeney, G. E. and Ramji, D. P. 1998. Characterisation and developmental regulation of the Xenopus laevis CCAAT-enhancer binding protein β gene. Mechanisms of Development 77(2), pp. 143-148.   (10.1016/S0925-4773(98)00128-2)
• Llewellyn, L., Ramsurn, V. P., Sweeney, G. E., Wigham, T. and Power, D. M. 1998. Expression of thyroid hormone receptor during early development of the sea bream (Sparus aurata). Annals of the New York Academy of Sciences 839(1), pp. 610-611.   (10.1111/j.1749-6632.1998.tb10893.x)

1997

• Santos, C. R. A., Power, D. M., Kille, P., Llewellyn, L., Ramsurn, V., Wigham, T. and Sweeney, G. E. 1997. Cloning and sequencing of a full-length sea bream (Sparus aurata) β-actin cDNA. Comparative Biochemistry and Physiology Part B: Biochemistry and Molecular Biology 117(2), pp. 185-189.   (10.1016/S0305-0491(96)00328-8)
• Kousteni, S., Tura, F., Sweeney, G. E. and Ramji, D. P. 1997. Sequence and expression analysis of a Xenopus laevis cDNA which encodes a homologue of mammalian 14-3-3 zeta protein. Gene 190(2), pp. 279-285.   (10.1016/S0378-1119(97)00013-9)

1996

• van der Wees, J., Matharu, P. J., de Roos, K., Destre ́e, O. H., Godsave, S. F., Durston, A. J. and Sweeney, G. E. 1996. Developmental expression and differential regulation by retinoic acid ofXenopus COUP-TF-A andCOUP-TF-B. Mechanisms of Development 54(2), pp. 173-184.   (10.1016/0925-4773(95)00471-8)

1995

• Kille, P., Kay, J. and Sweeney, G. E. 1995. Molecular biology and environmental induction of piscine metallothionein. Marine Environmental Research 39(1-4), pp. 107-110.   (10.1016/0141-1136(94)00046-R)

1993

• Kille, P., Kay, J. and Sweeney, G. E. 1993. Analysis of regulatory elements flanking metallothionein genes in Cd-tolerant fish (pike and stone loach). Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression 1216(1), pp. 55-64.   (10.1016/0167-4781(93)90037-E)
• Smith, T. S., Matharu, P. J. and Sweeney, G. E. 1993. Cloning and sequencing of a Xenopus homologue of the inducible orphan receptor NGFI-B. Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression 1173(2), pp. 239-242.   (10.1016/0167-4781(93)90189-K)

1992

• Matharu, P. J. and Sweeney, G. E. 1992. Cloning and sequencing of a COUP transcription factor gene expressed in Xenopus embryos. Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression 1129(3), pp. 331-334.   (10.1016/0167-4781(92)90512-X)

1987

• Sweeney, G. E., Brooks, A., Day, P. and Old, R. 1987. DNA sequence of the first exon and 5' flanking region of the 68-K serum albumin gene of Xenopus laevis. Nucleic Acids Research 15(14), pp. 5889.   (10.1093/nar/15.14.5889)