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Chen H.,Sun Yat Sen University | Zhang Y.,Sun Yat Sen University | Li S.,Sun Yat Sen University | Lin M.,Sun Yat Sen University | And 9 more authors.
General and Comparative Endocrinology | Year: 2011

Estrogen plays key roles in vertebrate reproductive system via estrogen receptors (ERs) as mediating pathways. In the present study, three full-length ERs cDNA sequences were isolated from a protogynous teleost, the orange-spotted grouper (Epinephelus coioides), and were 2235. bp for gERα, 1967. bp for gERβ1 and 2158. bp for gERβ2, respectively. Phylogenetic and amino acid alignment analyses showed that each gER was clustered in the corresponding taxonomic groups of the perciformes and exhibited high evolutional conservation in functional domains. RT-PCR revealed that gERs expressed at different levels in all the obtained tissues. gERα highly expressed in mature ovaries, gERβ1 mainly expressed in immature ovaries and gERβ2 varied greatly during ovarian development. During female to male sex reversal induced by 17α-methyltestosterone (MT) implantation, gERα decreased gradually, gERβ1 increased gradually, and gERβ2 decreased firstly and recovered subsequently in male stage. The present study speculated the potential roles of gERs during female maturation and female to male sex reversal induced by MT in the protogynous grouper E. coioides. © 2011 Elsevier Inc. Source

Xu S.-W.,Biocontrol | Wu J.-Y.,Biocontrol | Hu K.-S.,Biocontrol | Ping H.-L.,Biocontrol | And 2 more authors.
Fish and Shellfish Immunology | Year: 2011

T-cell surface glycoprotein CD8 consists of two distinguished chains, termed α and β chains, and functions as a co-receptor for the T-cell receptor by binding to MHC class I proteins. In this study we report the cloning and identification of both CD8α and CD8β genes from orange-spotted grouper (Epinephelus coioides). The predicted grouper CD8α and CD8β proteins were structurally similar to other fish especially to those of Pleuronectiformes. Real-time RT-PCR revealed that the CD8 mRNA was much higher in the thymus than in other immune organs, and the expression level were very low in stomach, liver, and brain. During embryonic development of the grouper, the highest CD8 transcripts were detected in the multi-cell stage, followed by muscle burl stage, which suggested that the multi-cell stage may be critical in CD8 transcript synthesis. Moreover, CD8 mRNA levels were examined in lymphocytes at different time treated with lipopolysaccharide (LPS), polyriboinosinic polyribocytidylic acid (PolyI:C), phytohemagglutinin (PHA), and concanavalin A (ConA). The result showed that the CD8 mRNA levels were significantly affected in time-dependent manner by PolyI:C, PHA, and ConA, but not by LPS. © 2010 Elsevier Ltd. Source

Shu H.,Guangzhou University | Chen H.,Guangdong Ocean University | Chen H.,Guangdong Medical College | Liu Y.,Chinese University of Hong Kong | And 3 more authors.
Comparative Biochemistry and Physiology Part - B: Biochemistry and Molecular Biology | Year: 2014

The peptide QRFP plays an important role in the regulation of vertebrate feeding behavior. In this study, we cloned the full length cDNA of a QRFP precursor in a teleost fish, the orange-spotted grouper (Epinephelus coioides). Sequence analysis has shown that the functional regions of QRFP in other vertebrates (QRFP-25 and QRFP-7) are conserved in orange-spotted grouper. RT-PCR demonstrated that the pre-processed mRNA of QRFP is widely expressed in orange-spotted grouper. Three days of food deprivation did not change the hypothalamic pre-processed QRFP expression. However, QRFP expression significantly increased when the fish were reefed after three days of fasting. Intraperitoneal injection of QRFP-25 peptide to orange-spotted grouper suppressed expression of orexin, but elevated expression of pro-opiomelanocortin (POMC) in the hypothalamus. We also investigated the effects of QRFP-25 on the expression of reproductive genes. The peptide suppressed the expression of seabream-type gonadotropin-releasing hormones (sbGnRH), luteinizing hormone beta subunit (LHβ) and follicle-stimulating hormone beta subunit (FSHβ) in vivo, as well as inhibited the expression of LHβ and FSHβ in pituitary cells in primary culture. Our results indicate that QRFP may play an inhibitory role in the regulation of feeding behavior and reproduction in orange-spotted grouper. © 2014 Elsevier Inc. Source

Zhang H.,Sun Yat Sen University | Chen H.,Sun Yat Sen University | Zhang Y.,Sun Yat Sen University | Li S.,Sun Yat Sen University | And 6 more authors.
General and Comparative Endocrinology | Year: 2013

Leptin plays key roles in body weight regulation, energy metabolism, food intake, reproduction and immunity in mammals. However, its function in teleosts is still unclear. In the present study, two leptin genes (gLepA and gLepB) and one leptin receptor gene (gLepR) were cloned and characterized in orange-spotted grouper (Epinephelus coioides). The cDNAs of gLepA and gLepB were 671. bp and 684. bp in length, encoding for proteins of 161 amino acid (aa) and 158 aa, respectively. The three-dimensional (3D) structures modeling of gLepA and gLepB showed strong conservation of tertiary structure with that of other vertebrates. The total length of gLepR cDNA was 4242. bp, encoding a protein of 1169 aa which contained all functionally important domains conserved among vertebrate LEPR. Tissue distribution analysis showed that gLepA was highly expressed in cerebellum, liver and ovary, while gLepB mRNA abundantly in the brain regions, as well as in the ovary with some extend. The gLepR was mainly expressed in kidney, head kidney and most of brain regions. Analysis of expression profiles of gLep and gLepR genes during the embryonic stages showed that high expression of gLepR was observed in the brain vesicle stage, while neither gLepA nor gLepB mRNA was detected during different embryonic stages. Finally, fasting and refeeding experiments were carried out to investigate the possible function of leptin genes in food intake and energy metabolism, and the results showed that a significant increase of gLepA expression in the liver was induced by food deprivation in both short-term (7. days) and long-term (3. weeks) fasting and gLepA mRNA upregulation was eliminated after refeeding, while gLepB wasn't detected in the liver of grouper during fasting. No significant differences in hypothalamic leptin and leptin receptor expression were found during short-term fasting and refeeding. Hepatic expression of gLepA mRNA increased significantly 9. h after a single meal. These results suggested gLepA, other than gLepB, functioned in the regulation of energy metabolism and food intake in this Perciform fish. © 2012 Elsevier Inc. Source

Yang Y.,Sun Yat Sen University | Yang Y.,Guangdong Daya Bay Fisheries Development Center | Xie Z.,Sun Yat Sen University | Peng C.,Sun Yat Sen University | And 5 more authors.
Mitochondrial DNA | Year: 2016

The complete mitochondrial genome of the Epinephelus tukula was presented in this study. The mitochondrial genome is 16,503 bp long and consists of 13 protein-coding genes, two rRNA genes, 22 tRNA genes and a control region. The gene order and composition of Epinephelus tukula mitochondrial genome was similar to that of most other vertebrates. The nucleotide compositions of the light strand are 28.37% of A, 29.00% of C, 26.36% of T and 16.26% of G. With the exception of the NADH dehydrogenase subunit 6 (ND6) and seven tRNA genes, all other mitochondrial genes are encoded on the heavy strand. © 2014 Informa UK Ltd. Source

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