- Email: [email protected]
International Symposium for Fish Growth and Reproduction
General and Comparative Endocrinology 167 (2010) 339
Contents lists available at ScienceDirect
General and Comparative Endocrinology journal homepage: www.elsevier.com/locate/ygcen
Editorial
International Symposium for Fish Growth and Reproduction
The 2nd International Symposium for Fish Growth and Reproduction (ISFGR) was hosted in the University of Hong Kong in Hong Kong Special Administrative Region of China from June 20 to 21, 2009. The ISFGR meeting was started in 2003 by Prof. Ching-Fong Chang in National Taiwan Ocean University (Keelung, Taiwan) with the primary objective to provide a platform for updating recent progress, exchange of research ideas, and sprouting potential collaborations among scientists from different countries working on reproductive and growth physiology and endocrinology in fish models. The 2nd ISFGR in Hong Kong was organized as a satellite symposium for the 16th International Congress of Comparative Endocrinology and the program was well-attended by 132 delegates from 16 countries. With the support of Dr. Robert Dores, this issue of General and Comparative Endocrinology is dedicated to the papers from the oral presentations by invited speakers for the 2nd ISFGR. In this special issue, the recent progress in fish endocrinology on the development of research tools as well as the new findings in appetite control, growth regulation, modulation of reproductive functions, mechanisms for oocyte maturation and sex determination have been addressed. For the development of research tools, attempts have been made for the production of monoclonal antibodies for fish hormones including the different subunits of gonadotropins and other pituitary hormones related to the GH lineage. These monoclonal antibodies are a nice addition to the traditional polyclonal antisera used in fish studies, in particular for high-end applications in florescence-based flow cytometry and epitope mapping of functional domains in target hormones. Besides the monoclonal antibodies, recombinant proteins for fish FSH and LH have been successfully produced in silkworm larvae using baculovirus carrying the respective b subunit cDNA linked directly with the cDNA encoding the common a subunit. The recombinant gonadotropins of the fish origin produced in this eukaryotic expression system were found to be biologically active and will serve as useful tools for dissecting the differential functions of the two gonadotropins as well as for induced spawning in cultured fish with commercial value. Similar to mammals, proper feeding is required for normal growth and reproduction in fish models. In this issue of General and Comparative Endocrinology, the recent progress on feeding control in fish by appetite regulators, nutritional status, and environmental factors has been reviewed and new information has been presented in goldfish on functional interactions of hypothalamic aMSH and NPY neurons in regulating food intake. Regarding the control of body growth, the signaling mechanisms for IGF-induced myogenesis as well as the hepatic actions of somatostatin on GH receptor expression and IGF biosynthesis and secretion have been
0016-6480/$ - see front matter Ó 2010 Published by Elsevier Inc. doi:10.1016/j.ygcen.2010.03.007
unveiled. Besides its effect on body growth, the novel actions of IGF on GnRH receptor and gonadotropin expression in the fish pituitary have also been addressed. These findings provide new insights on IGF modulation of pituitary sensitivity to GnRH induction and shed light on the new mechanisms for the cross-talk between somatotropic and gonadotropic axes. Although ghrelin is well known for its orexigenic effect and GH-releasing action, its role in reproduction appears to be different between the fish and mammals and new evidence was put forward supporting the role of ghrelin as an autocrine/paracrine factor acting in the gonad of fish models. At the gonadal level, mainly based on the studies in zebrafish, local communication between the oocyte and follicular cell layers via the paracrine interactions of EGF and activin systems has been demonstrated, which may play a key role in the processes of folliculogenesis and oocyte maturation. Apart from the endocrine mechanisms regulating growth and reproduction, new information has been reported for the fundamental issue of sex determination. In this case, development studies in common carp have revealed the possible involvement of SF-1 and different isoforms of Cy19 in sex differentiation. Based on parallel studies in the protandrous black porgy, these factors may act together with other transcription factors (e.g., DMRT1, DAX1, Wnt4 and Foxl2) to control the process of sex reversal in fish. As a member of International Congress of Comparative Endocrinology, it was a pleasure and privilege for me to organize the 2nd ISFGR in Hong Kong. However, the ISFGR meeting would not be possible without the encouragement and support from Dr. ChingFong Chang and input from Dr. John P. Chang in selecting an excellent list of speakers. Special thanks are given to Dr. Robert Dores for his help in editing the special issue of General and Comparative Endocrinology and to the Gene Company Limited (Hong Kong) and School of Biological Sciences, University of Hong Kong, for the financial support and provision of meeting venue, respectively. The outstanding contributions by the session chairs and invited speakers are also acknowledged. We are also in debt to our staffs in the School of Biological Sciences including Mr. K.Y. Ng and Ms. Wendy K.W. Ko for the preparation and smooth operation of the meeting and Dr. Fredrick C.C. Leung and his team in setting up the website for the symposium. Anderson O.L. Wong * Endocrinology Division, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong * Fax: +852 2559 9114. E-mail address: [email protected] Available online 16 March 2010
Contents lists available at ScienceDirect
General and Comparative Endocrinology journal homepage: www.elsevier.com/locate/ygcen
Editorial
International Symposium for Fish Growth and Reproduction
The 2nd International Symposium for Fish Growth and Reproduction (ISFGR) was hosted in the University of Hong Kong in Hong Kong Special Administrative Region of China from June 20 to 21, 2009. The ISFGR meeting was started in 2003 by Prof. Ching-Fong Chang in National Taiwan Ocean University (Keelung, Taiwan) with the primary objective to provide a platform for updating recent progress, exchange of research ideas, and sprouting potential collaborations among scientists from different countries working on reproductive and growth physiology and endocrinology in fish models. The 2nd ISFGR in Hong Kong was organized as a satellite symposium for the 16th International Congress of Comparative Endocrinology and the program was well-attended by 132 delegates from 16 countries. With the support of Dr. Robert Dores, this issue of General and Comparative Endocrinology is dedicated to the papers from the oral presentations by invited speakers for the 2nd ISFGR. In this special issue, the recent progress in fish endocrinology on the development of research tools as well as the new findings in appetite control, growth regulation, modulation of reproductive functions, mechanisms for oocyte maturation and sex determination have been addressed. For the development of research tools, attempts have been made for the production of monoclonal antibodies for fish hormones including the different subunits of gonadotropins and other pituitary hormones related to the GH lineage. These monoclonal antibodies are a nice addition to the traditional polyclonal antisera used in fish studies, in particular for high-end applications in florescence-based flow cytometry and epitope mapping of functional domains in target hormones. Besides the monoclonal antibodies, recombinant proteins for fish FSH and LH have been successfully produced in silkworm larvae using baculovirus carrying the respective b subunit cDNA linked directly with the cDNA encoding the common a subunit. The recombinant gonadotropins of the fish origin produced in this eukaryotic expression system were found to be biologically active and will serve as useful tools for dissecting the differential functions of the two gonadotropins as well as for induced spawning in cultured fish with commercial value. Similar to mammals, proper feeding is required for normal growth and reproduction in fish models. In this issue of General and Comparative Endocrinology, the recent progress on feeding control in fish by appetite regulators, nutritional status, and environmental factors has been reviewed and new information has been presented in goldfish on functional interactions of hypothalamic aMSH and NPY neurons in regulating food intake. Regarding the control of body growth, the signaling mechanisms for IGF-induced myogenesis as well as the hepatic actions of somatostatin on GH receptor expression and IGF biosynthesis and secretion have been
0016-6480/$ - see front matter Ó 2010 Published by Elsevier Inc. doi:10.1016/j.ygcen.2010.03.007
unveiled. Besides its effect on body growth, the novel actions of IGF on GnRH receptor and gonadotropin expression in the fish pituitary have also been addressed. These findings provide new insights on IGF modulation of pituitary sensitivity to GnRH induction and shed light on the new mechanisms for the cross-talk between somatotropic and gonadotropic axes. Although ghrelin is well known for its orexigenic effect and GH-releasing action, its role in reproduction appears to be different between the fish and mammals and new evidence was put forward supporting the role of ghrelin as an autocrine/paracrine factor acting in the gonad of fish models. At the gonadal level, mainly based on the studies in zebrafish, local communication between the oocyte and follicular cell layers via the paracrine interactions of EGF and activin systems has been demonstrated, which may play a key role in the processes of folliculogenesis and oocyte maturation. Apart from the endocrine mechanisms regulating growth and reproduction, new information has been reported for the fundamental issue of sex determination. In this case, development studies in common carp have revealed the possible involvement of SF-1 and different isoforms of Cy19 in sex differentiation. Based on parallel studies in the protandrous black porgy, these factors may act together with other transcription factors (e.g., DMRT1, DAX1, Wnt4 and Foxl2) to control the process of sex reversal in fish. As a member of International Congress of Comparative Endocrinology, it was a pleasure and privilege for me to organize the 2nd ISFGR in Hong Kong. However, the ISFGR meeting would not be possible without the encouragement and support from Dr. ChingFong Chang and input from Dr. John P. Chang in selecting an excellent list of speakers. Special thanks are given to Dr. Robert Dores for his help in editing the special issue of General and Comparative Endocrinology and to the Gene Company Limited (Hong Kong) and School of Biological Sciences, University of Hong Kong, for the financial support and provision of meeting venue, respectively. The outstanding contributions by the session chairs and invited speakers are also acknowledged. We are also in debt to our staffs in the School of Biological Sciences including Mr. K.Y. Ng and Ms. Wendy K.W. Ko for the preparation and smooth operation of the meeting and Dr. Fredrick C.C. Leung and his team in setting up the website for the symposium. Anderson O.L. Wong * Endocrinology Division, School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong * Fax: +852 2559 9114. E-mail address: [email protected] Available online 16 March 2010