1
|
Sobrido-Cameán D, Yáñez-Guerra LA, Deber A, Freire-Delgado M, Cacheiro-Vázquez R, Rodicio MC, Tostivint H, Anadón R, Barreiro-Iglesias A. Differential expression of somatostatin genes in the central nervous system of the sea lamprey. Brain Struct Funct 2021; 226:1031-1052. [PMID: 33532926 DOI: 10.1007/s00429-021-02224-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 01/19/2021] [Indexed: 01/29/2023]
Abstract
The identification of three somatostatin (SST) genes (SSTa, SSTb, and SSTc) in lampreys (Tostivint et al. Gen Comp Endocrinol 237:89-97 https://doi.org/10.1016/j.ygcen.2016.08.006 , 2016) prompted us to study their expression in the brain and spinal cord of the sea lamprey by in situ hybridization. These three genes were only expressed in equivalent neuronal populations in the hypothalamus. In other regions, SST transcripts showed clear differential expression. In the telencephalon, SSTc-positive cells were observed in the medial pallium, ventral part of the lateral pallium, striatum, subhippocampal lobe, and preoptic region. In the diencephalon, SSTa-positive cells were observed in the thalamus and SSTc-positive cells in the prethalamus, posterior tubercle, pretectal area, and nucleus of the medial longitudinal fascicle. In the midbrain, SSTc-positive cells were observed in the torus semicircularis, lateral reticular area, and perioculomotor tegmentum. Different SSTa- and SSTc-positive populations were observed in the isthmus. SSTc neurons were also observed in the rostral octavolateralis area and caudal rhombencephalon. In the spinal cord, SSTa was expressed in cerebrospinal-fluid-contacting (CSF-c) neurons and SSTc in non-CSF-c interneurons. Comparison with previous immunohistochemical studies using anti-SST-14 antibodies strongly suggests that SST-14-like neurons correspond with the SSTa populations. Thus, the SSTc populations were not reported previously in immunohistochemical studies. Cluster-based analyses and alignments of mature peptides suggested that SSTa is an ortholog of SST1 and that SSTb is closely related to SST2 and SST6. These results provide important new insights into the evolution of the somatostatinergic system in vertebrates.
Collapse
Affiliation(s)
- D Sobrido-Cameán
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain.,Department of Zoology, University of Cambridge, Cambridge, UK
| | | | - A Deber
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain
| | - M Freire-Delgado
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain
| | - R Cacheiro-Vázquez
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain
| | - M C Rodicio
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain
| | - H Tostivint
- Molecular Physiology and Adaptation, UMR7221, CNRS and Muséum National D'Histoire Naturelle, Paris, France
| | - R Anadón
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain
| | - A Barreiro-Iglesias
- Department of Functional Biology, Faculty of Biology, CIBUS, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, A Coruña, Spain.
| |
Collapse
|
2
|
Feng P, Tian C, Lin X, Jiang D, Shi H, Chen H, Deng S, Zhu C, Li G. Identification, Expression, and Functions of the Somatostatin Gene Family in Spotted Scat ( Scatophagus argus). Genes (Basel) 2020; 11:genes11020194. [PMID: 32059553 PMCID: PMC7073721 DOI: 10.3390/genes11020194] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/31/2020] [Accepted: 02/07/2020] [Indexed: 12/24/2022] Open
Abstract
Somatostatins (SSTs) are a family of proteins consisting of structurally diverse polypeptides that play important roles in the growth regulation in vertebrates. In the present study, four somatostatin genes (SST1, SST3, SST5, and SST6) were identified and characterized in the spotted scat (Scatophagus argus). The open reading frames (ORFs) of SST1, SST3, SST5, and SST6 cDNA consist of 372, 384, 321, and 333 bp, respectively, and encode proteins of 123, 127, 106, and 110 amino acids, respectively. Amino acid sequence alignments indicated that all SST genes contained conserved somatostatin signature motifs. Real-time PCR analysis showed that the SST genes were expressed in a tissue specific manner. When liver fragments were cultured in vitro with synthetic peptides (SST1, SST2, or SST6 at 1 μM or 10 μM) for 3 h or 6 h, the expression of insulin-like growth factor 1 and 2 (Igf-1 and Igf-2) in the liver decreased significantly. Treatment with SST5 had no significant effect on Igf-1 and Igf-2 gene expression. This study provides an enhanced understanding of the gene structure and expression patterns of the SST gene family in S. argus. Furthermore, this study provides a foundation for future exploration into the role of SST genes in growth and development.
Collapse
Affiliation(s)
- Peizhe Feng
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (P.F.); (C.T.); (X.L.); (D.J.); (H.S.); (H.C.); (S.D.); (C.Z.)
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
| | - Changxu Tian
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (P.F.); (C.T.); (X.L.); (D.J.); (H.S.); (H.C.); (S.D.); (C.Z.)
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
- Marine Ecology and Aquaculture Environment of Zhanjiang, Zhanjiang 524088, China
| | - Xinghua Lin
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (P.F.); (C.T.); (X.L.); (D.J.); (H.S.); (H.C.); (S.D.); (C.Z.)
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
| | - Dongneng Jiang
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (P.F.); (C.T.); (X.L.); (D.J.); (H.S.); (H.C.); (S.D.); (C.Z.)
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
- Marine Ecology and Aquaculture Environment of Zhanjiang, Zhanjiang 524088, China
| | - Hongjuan Shi
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (P.F.); (C.T.); (X.L.); (D.J.); (H.S.); (H.C.); (S.D.); (C.Z.)
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
- Marine Ecology and Aquaculture Environment of Zhanjiang, Zhanjiang 524088, China
| | - Huapu Chen
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (P.F.); (C.T.); (X.L.); (D.J.); (H.S.); (H.C.); (S.D.); (C.Z.)
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
- Marine Ecology and Aquaculture Environment of Zhanjiang, Zhanjiang 524088, China
| | - Siping Deng
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (P.F.); (C.T.); (X.L.); (D.J.); (H.S.); (H.C.); (S.D.); (C.Z.)
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
- Marine Ecology and Aquaculture Environment of Zhanjiang, Zhanjiang 524088, China
| | - Chunhua Zhu
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (P.F.); (C.T.); (X.L.); (D.J.); (H.S.); (H.C.); (S.D.); (C.Z.)
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
- Marine Ecology and Aquaculture Environment of Zhanjiang, Zhanjiang 524088, China
| | - Guangli Li
- Fisheries College, Guangdong Ocean University, Zhanjiang 524088, China; (P.F.); (C.T.); (X.L.); (D.J.); (H.S.); (H.C.); (S.D.); (C.Z.)
- Guangdong Research Center on Reproductive Control and Breeding Technology of Indigenous Valuable Fish Species, Zhanjiang 524088, China
- Marine Ecology and Aquaculture Environment of Zhanjiang, Zhanjiang 524088, China
- Correspondence: ; Tel.: +86-75-92-383-124; Fax: +86-75-92-382-459
| |
Collapse
|
3
|
Tostivint H, Gaillard AL, Mazan S, Pézeron G. Revisiting the evolution of the somatostatin family: Already five genes in the gnathostome ancestor. Gen Comp Endocrinol 2019; 279:139-147. [PMID: 30836103 DOI: 10.1016/j.ygcen.2019.02.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/10/2019] [Accepted: 02/28/2019] [Indexed: 11/21/2022]
Abstract
The somatostatin (SST) family members are a group of neuropeptides that are best known for their role in the regulation of growth, development and metabolism. The occurrence of six paralogous SST genes named SST1, SST2, SST3, SST4, SST5 and SST6 has been reported in vertebrates. It has been proposed that SST1, SST2 and SST5 arose in 2R from a common ancestral gene. SST3 and SST6 would have been subsequently generated by tandem duplications of the SST1 and SST2 genes respectively, at the base of the actinopterygian lineage. SST4 is thought to have appeared more recently from SST1, in teleost-specific 3R. In order to gain more insights into the SST gene family in vertebrates, we sought to identify which paralogs of this family are present in cartilaginous fish. For this purpose, we first searched the recently available genome and transcriptome databases from the catshark Scyliorhinus canicula. In a previous study, three S. canicula SST genes, called at that time SSTa, SSTb and SSTc, were identified and proposed to correspond to SST1, SST5 and SST2 respectively. In the present work, two additional SST genes, called SSTd and SSTe, were found in S. canicula plus two other chondrichtyan species, elephant shark (Callorhinchus milii) and whale shark (Rhincodon typus). Phylogeny and synteny analyses were then carried out in order to reveal the evolutionary relationships of SSTd and SSTe with other vertbrates SSTs. We showed that SSTd and SSTe correspond to SST2 and SST3 respectively, while SSTc corresponds to SST6 and not to SST2 as initially proposed. Our investigations in other vertebrate species also led us to find that the so-called SST2 gene in chicken, lungfish, sturgeons and teleosts actually corresponds to SST6. Conversely, the so-called SST6 gene in actinopterygians corresponds to SST2. Taken together, our results suggest that: i) SST3 and SST6 were already present in the gnathostome ancestor, much earlier than previously thought; ii) SST6 was also present in the tetrapod ancestor and still occurs in living birds; with this respect, it is likely that SST6 was independently lost several times during evolution: in amphibians, squamates and mammals; iii) SST2, SST3 and SST5 were probably lost in euteleosts, sarcopterygians and tetrapods, respectively.
Collapse
Affiliation(s)
- Hervé Tostivint
- Physiologie moléculaire et adaptation UMR 7221 CNRS and Muséum National d'Histoire Naturelle, Paris, France.
| | - Anne-Laure Gaillard
- Physiologie moléculaire et adaptation UMR 7221 CNRS and Muséum National d'Histoire Naturelle, Paris, France
| | - Sylvie Mazan
- Biologie intégrative des organismes marins, UMR 7232 CNRS, Observatoire Océanologique, Sorbonne Université, Banyuls-sur-Mer, France
| | - Guillaume Pézeron
- Physiologie moléculaire et adaptation UMR 7221 CNRS and Muséum National d'Histoire Naturelle, Paris, France
| |
Collapse
|
4
|
Feng X, Yu X, Pang M, Liu H, Tong J. Molecular characterization and expression of three preprosomatostatin genes and their association with growth in common carp (Cyprinus carpio). Comp Biochem Physiol B Biochem Mol Biol 2014; 182:37-46. [PMID: 25536408 DOI: 10.1016/j.cbpb.2014.12.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2014] [Revised: 12/12/2014] [Accepted: 12/13/2014] [Indexed: 12/21/2022]
Abstract
Somatostatins (SSs) are a structurally diverse family of peptides that play important roles in the regulation of growth, development and metabolism in vertebrates. In this study, three preprosomatostatin genes (PSSs) in the common carp, Cyprinus carpio (Cc) were identified and characterized. Based on cloned sequences and genome BLAST, six isoforms of the PSS gene in C. carpio (CcPSS) were identified and included CcPSS1a and CcPSS1b, CcPSS2a and CcPSS2b, and finally, CcPSS3a and CcPSS3b. The open reading frames (ORF) of CcPSS1a, CcPSS2a and CcPSS3a consist of 345, 336 and 363 nucleotides. During embryonic development, the expressions of CcPSS2 and CcPSS3 were first observed at the stage of optic vesicle, and CcPSS1 mRNA was initially detected at the stage of muscular effect. The highest mRNA levels of CcPSS1, CcPSS2 and CcPSS3 were observed at 1-day post-hatch (dph), 2-dph and the stage of heart beating, respectively. In the adult brain, the distributions of three CcPSS mRNAs were differential but overlapping in the hypothalamus, telencephalon and medulla oblongata. For peripheral tissues, all three CcPSS mRNAs were detected in the mid-intestine, and CcPSS1 and CcPSS3 mRNAs were also expressed in the liver. Owing to the importance of somatostatins on regulating growth, functional mutations of CcPSSs were identified in a C. carpio population. A total of 23 polymorphic sites were detected in CcPSS1a and CcPSS3a. Of them, two SNPs (CcPSS1a-g.922C>T, and CcPSS3a-g.1125C>A) were significantly associated with growth traits, indicating their potential applications in gene (marker)-assisted selective breeding in C. carpio.
Collapse
Affiliation(s)
- Xiu Feng
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xiaomu Yu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, China
| | - Meixia Pang
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haiyang Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jingou Tong
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, China.
| |
Collapse
|
5
|
Acclimation to different environmental salinities induces molecular endocrine changes in the GH/IGF-I axis of juvenile gilthead sea bream (Sparus aurata L.). J Comp Physiol B 2014; 185:87-101. [PMID: 25395251 DOI: 10.1007/s00360-014-0871-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Revised: 10/15/2014] [Accepted: 10/26/2014] [Indexed: 02/03/2023]
Abstract
To assess the role of the GH/IGF-I axis in osmotic acclimation of the gilthead seabream Sparus aurata, juvenile specimens were acclimated to four environmental salinities: hyposmotic (5 ‰), isosmotic (12 ‰) and hyperosmotic (40 and 55 ‰). The full-length cDNAs for both pituitary adenylate cyclase-activating peptide (PACAP) and prepro-somatostatin-I (PSS-I), the precursor for mature somatostatin-I (SS-I), were cloned. Hypothalamic PACAP and PSS-I, hypophyseal growth hormone (GH) and prolactin (PRL), and hepatic insulin-like growth factor-I (IGF-I) mRNA expression levels were analyzed in the four rearing salinities tested. PACAP and IGF-I mRNA values increased significantly in response to both 5 and 55 ‰ salinities, showing a U-shaped curve relationship with the basal level in the 40 ‰ group. Hypothalamic PSS-I expression increased strongly in the 55 ‰ environment. GH mRNA levels did not change in any of the tested environmental salinities. PRL mRNA maximum levels were encountered in the 5 and 12 ‰ environments, but significantly down-regulated in the 40 ‰. Plasma cortisol levels significantly increased in the 40 ‰ environment. These results are discussed in relation to the well-known high adaptability of Sparus aurata to different environmental salinities and the role of the GH/IGF-I axis in this process.
Collapse
|
6
|
Wang B, Qin C, Zhang C, Jia J, Sun C, Li W. Differential involvement of signaling pathways in the regulation of growth hormone release by somatostatin and growth hormone-releasing hormone in orange-spotted grouper (Epinephelus coioides). Mol Cell Endocrinol 2014; 382:851-9. [PMID: 24183819 DOI: 10.1016/j.mce.2013.10.025] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 10/20/2013] [Accepted: 10/22/2013] [Indexed: 11/25/2022]
Abstract
Somatostatin is the most effective inhibitor of GH release, and GHRH was recently identified as one of the primary GH-releasing factors in teleosts. In this study, we analyzed the possible intracellular transduction pathways that are involved in the mechanisms induced by SRIF and GHRH to regulate GH release. Using a pharmacological approach, the blockade of the PLC/IP/PKC pathway reversed the SRIF-induced inhibition of GH release but did not affect the GHRH-induced stimulation of GH release. Furthermore, SRIF reduced the GH release induced by two PKC activators. Inhibitors of the AC/cAMP/PKA pathway reversed both the SRIF- and GHRH-induced effects on GH release. Moreover, the GH release evoked by forskolin and 8-Br-cAMP were completely abolished by SRIF. The blockade of the NOS/NO pathway attenuated the GHRH-induced GH release but had minimal effects on the inhibitory actions of SRIF. In addition, inhibitors of the sGC/cGMP pathway did not modify the SRIF- or GHRH-induced regulation of GH release. Taken together, these findings indicate that the SRIF-induced inhibition of GH release is mediated by both the PLC/IP/PKC and the AC/cAMP/PKA pathways and not by the NOS/NO/sGC/cGMP pathway. In contrast, the GHRH-induced stimulation of GH secretion is mediated by both the AC/cAMP/PKA and the NOS/NO pathways and is independent of the sGC/cGMP pathway and the PLC/IP/PKC system.
Collapse
Affiliation(s)
- Bin Wang
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Chaobin Qin
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Cong Zhang
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Jirong Jia
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Caiyun Sun
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Wensheng Li
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China.
| |
Collapse
|
7
|
Sun C, Duan D, Li B, Qin C, Jia J, Wang B, Dong H, Li W. UII and UT in grouper: cloning and effects on the transcription of hormones related to growth control. J Endocrinol 2014; 220:35-48. [PMID: 24169050 DOI: 10.1530/joe-13-0282] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Urotensin II (UII) is a cyclic peptide that was originally extracted from the caudal neurosecretory system (CNSS) of fish. UII is well known to exhibit cardiovascular, ventilatory, and motor effects in vertebrates. Studies have reported that UII exerts mitogenic effects and can act as an autocrine/paracrine growth factor in mammals. However, similar information in fish is limited. In this study, the full-length cDNAs of UII and its receptor (UT) were cloned and characterized in the orange-spotted grouper. UII and UT were expressed ubiquitously in various tissues in grouper, and particularly high levels were observed in the CNSS, CNS, and ovary. A functional study showed that UT was coupled with intracellular Ca2+ mobilization in HEK293 cells. Studies carried out using i.p. injections of UII in grouper showed the following: i) in the hypothalamus, UII can significantly stimulate the mRNA expression of ghrh and simultaneously inhibit the mRNA expression of somatostatin 1 (ss1) and ss2 3 h after injection; ii) in the pituitary, UII also significantly induced the mRNA expression of gh 6 and 12 h after injection; and iii) in the liver, the mRNA expression levels of ghr1/ghr2 and igf1/igf2 were markedly increased 12 and 3 h after the i.p. injection of UII respectively. These results collectively indicate that the UII/UT system may play a role in the promotion of the growth of the orange-spotted grouper.
Collapse
Affiliation(s)
- Caiyun Sun
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, No. 135, XinGang West Road, Guangzhou 510275, People's Republic of China
| | | | | | | | | | | | | | | |
Collapse
|
8
|
Li Y, Liu X, Zhang Y, Ma X, Lin H. Effects of cysteamine on mRNA levels of growth hormone and its receptors and growth in orange-spotted grouper (Epinephelus coioides). FISH PHYSIOLOGY AND BIOCHEMISTRY 2013; 39:605-613. [PMID: 23064985 DOI: 10.1007/s10695-012-9723-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 09/19/2012] [Indexed: 06/01/2023]
Abstract
Effects of cysteamine (CS) on growth hormone (GH) mRNA, two types of growth hormone receptor (GHR) mRNAs and growth rate in orange-spotted grouper (Epinephelus coioides) were investigated. CS could cause a modification in the structure of somatostatin, which is the most important neuroendocrine inhibitor of basal and stimulated growth hormone synthesis and release, and renders it nonimmunoreactive probably through interaction with the disulfide bonds. In the present study, cysteamine hydrochloride (CSH) enhanced the level of pituitary GH mRNA in a dose-dependent manner through attenuating or deleting the inhibiting action of somatostatin on GH mRNA expression. CSH at relatively low doses (from 1 to 3 mg/g diet) enhanced the levels of two types of GHR mRNAs in dose-dependent manner, whereas the stimulation induced by CSH declined from the peak at higher dose of CSH (4 mg/g diet). It might be attributed to the variation in GH-induced up-regulation of GHRs at different doses of GH. Feeding of CSH could induce remarkable enhancement of growth rate in orange-spotted grouper. In addition, the stimulatory effect of CSH could be potentiated by the additive effect of luteinizing hormone-releasing hormone analog (LHRH-A). Compared with individual treatments, combined feeding of CSH and LHRH-A caused more efficient elevation of growth rate after 8 weeks of feeding. CSH and LHRH-A individually and in combination remarkably increased the levels of GH and GHR mRNAs compared with the control. The combined administration of CSH and LHRH-A in diet was most effective to enhance the level of GH and GHR1 mRNA. The morphological characteristics of the experimental fish were evaluated. Compared with control, the ratios of muscle RNA/DNA, condition factors (CF) and feed conversion efficiency (FCE) were significantly enhanced in the treated groups, while the highest values were observed in the combined treatment. All the results suggested that CSH (1-3 mg/g diet) is an effective, economical and feasible feed additive in orange-spotted grouper culture.
Collapse
Affiliation(s)
- Yun Li
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | | | | | | | | |
Collapse
|
9
|
Quan FB, Kenigfest NB, Mazan S, Tostivint H. Molecular cloning of the cDNAs encoding three somatostatin variants in the dogfish (Scylorhinus canicula). Gen Comp Endocrinol 2013; 180:1-6. [PMID: 23103685 DOI: 10.1016/j.ygcen.2012.10.007] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 10/13/2012] [Accepted: 10/17/2012] [Indexed: 11/18/2022]
Abstract
It has been recently shown that the somatostatin gene family was likely composed of at least three paralogous genes in the common ancestor of all extant jawed vertebrates. These three genes, namely SS1, SS2 and SS5, are thought to have been generated through the two rounds of whole-genome duplications (2R) that took place early during the vertebrate evolution. In the present study, we report the cloning of three distinct somatostatin cDNAs from the dogfish Scylorhinus canicula, a member of the group of cartilaginous fish. We decided to call these cDNAs, at least provisionally, SSa, SSb and SSc, respectively. Two of them, SSa and SSb, encode proteins that both contain the same tetradecapeptide sequence at their C-terminal extremity (AGCKNFFWKTFTSC). This putative peptide is identical to that generated by the SS1 gene in other vertebrate species. The last cDNA, SSc, encodes a protein that contains at its C-terminal extremity the same peptide sequence as that generated by the SS2 gene in teleosts (APCKNFFWKTFTSC). Phylogenetic analysis showed that the SSa and SSc genes likely correspond to the dogfish counterparts of the SS1 and SS2 genes, respectively. In contrast, the phylogenetic status of the SSb gene is less clear. Several lines of evidence suggest that it could correspond to the SS5 gene, but this view will need to be confirmed, for example by synteny analysis. Finally, RT-PCR analysis revealed that SSa, SSb and SSc genes are differentially expressed in dogfish tissues, suggesting that the corresponding peptides may exert distinct functions.
Collapse
Affiliation(s)
- Feng B Quan
- Evolution des Régulations Endocriniennes, UMR 7221 CNRS and Muséum National d'Histoire Naturelle, Paris, France
| | | | | | | |
Collapse
|
10
|
Wu S, Li B, Lin H, Li W. Stimulatory effects of neuropeptide Y on the growth of orange-spotted grouper (Epinephelus coioides). Gen Comp Endocrinol 2012; 179:159-66. [PMID: 22926329 DOI: 10.1016/j.ygcen.2012.08.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2012] [Revised: 07/28/2012] [Accepted: 08/05/2012] [Indexed: 01/18/2023]
Abstract
Neuropeptide Y (NPY) is a member of the pancreatic polypeptide family which is a potent orexigenic peptide known to date in mammals and teleost. This study was carried out to investigate the effects of NPY on food intake and growth of orange-spotted grouper (Epinephelus coioides). Synthetic grouper NPY (gNPY) was given orally at the dose of 0.5, 1.0 and 2.0 μg/g feed for 50 days, results showed that NPY treatment (1.0 and 2.0 μg/g feed) significantly increased growth rate, weight gain, feed conversion efficiency (FCE) and pituitary growth hormone (GH) mRNA level than the control group (p<0.05). Furthermore, high level secretion of gNPY was expressed and purified in the Pichia pastoris expression system. The bioactivity of recombinant gNPY was confirmed by its ability to up-regulate GH mRNA expression in vivo and in vitro and down-regulate preprosomatostatin I (PSSI) mRNA expression in vivo. These results demonstrate that NPY has stimulatory effects on food intake as well as growth of grouper as in other teleost fish, also indicate that recombinant gNPY from P. pastoris has the same bioactivity as synthetic gNPY and has the potential to be used as a feed additive for both research and aquatic application.
Collapse
Affiliation(s)
- Shuge Wu
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
| | | | | | | |
Collapse
|
11
|
Molecular basis and genetic improvement of economically important traits in aquaculture animals. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s11434-012-5213-0] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
|
12
|
Liu Y, Lu D, Zhang Y, Li S, Liu X, Lin H. The evolution of somatostatin in vertebrates. Gene 2010; 463:21-8. [DOI: 10.1016/j.gene.2010.04.016] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2010] [Revised: 04/23/2010] [Accepted: 04/29/2010] [Indexed: 11/25/2022]
|
13
|
Yu Y, Chang JP. Involvement of protein kinase C and intracellular Ca2+ in goldfish brain somatostatin-28 inhibitory action on growth hormone release in goldfish. Gen Comp Endocrinol 2010; 168:71-81. [PMID: 20403359 DOI: 10.1016/j.ygcen.2010.04.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/07/2010] [Revised: 03/17/2010] [Accepted: 04/14/2010] [Indexed: 10/19/2022]
Abstract
Goldfish brain somatostatin-28 (gbSS-28) is present in brain and pituitary tissues of goldfish. We assessed whether gbSS-28 targets Ca(2+) and/or protein kinase C (PKC)-dependent signaling cascades in inhibiting growth hormone (GH) release. gbSS-28 decreased basal GH release from primary cultures of dispersed goldfish pituitary cells and intracellular free calcium levels ([Ca(2+)](i)) in goldfish somatotropes. gbSS-28 partially reduced [Ca(2+)](i) and GH responses induced by two endogeneous gonadotropin-releasing hormones (GnRHs), salmon (s)GnRH and chicken (c)GnRH-II. Furthermore, gbSS-28 reduced GH increases and abolished [Ca(2+)](i) elevations elicited by two PKC activators, tetradecanoyl 4beta-phorbol-13-acetate and dioctanyl glycerol. The PKC inhibitors Gö6976 and Bis II abolished [Ca(2+)](i) responses to PKC activators, but only attenuated GnRH-induced increases in [Ca(2+)](i) and did not alter basal [Ca(2+)](i). In cells pretreated with Bis II, gbSS-28 further reduced basal [Ca(2+)](i). Our results suggest that gbSS-28 inhibits GnRH-induced GH release in part by attenuating PKC-mediated GnRH [Ca(2+)](i) signals. gbSS-28 reduces basal GH release also via reduction in [Ca(2+)](i) but PKC is not involved in this regard.
Collapse
Affiliation(s)
- Y Yu
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | | |
Collapse
|
14
|
Haiyan D, Wensheng L, Haoran L. Comparative analyses of sequence structure, evolution, and expression of four somatostatin receptors in orange-spotted grouper (Epinephelus coioides). Mol Cell Endocrinol 2010; 323:125-36. [PMID: 20347929 DOI: 10.1016/j.mce.2010.03.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/08/2009] [Revised: 03/16/2010] [Accepted: 03/19/2010] [Indexed: 11/27/2022]
Abstract
Somatostatins (SSs) and somatostatin receptors (SSTRs) play important roles in the growth, development and metabolism of vertebrates. In the present study, four SSTRs were isolated from orange-spotted grouper (Epinephelus coioides), a coral fish of high commercial value cultivated in Southeast Asia. Phylogenetic tree analysis grouped the four SSTRs as two distinct groups of SSTR1 and SSTR2/3/5. Four SSTRs exhibited high homology across the vertebrates. The expression of four grouper SSTR mRNAs was studied in 11 tissues. The highest level of SSTR1 mRNA was found in forebrain. The mRNAs of SSTR2 and SSTR3 were highly expressed in pituitary, forebrain and liver. The levels of SSTR5 mRNA were low in most tissues except for pituitary and intestine. The expression of four grouper SSTR mRNAs was investigated in seven embryonic stages and five early larval development stages. The highest levels of SSTR1 and 2 mRNAs appeared during hatching, while the highest levels of SSTR3 and 5 mRNAs were found in brain vesicle stage. Intraperitoneal injection of SS14 significantly increased the levels of all four SSTR mRNAs in pituitary and SSTR1, 3 mRNAs in liver in a dose-dependent manner, but no effect on SSTR2 and 5 in liver. These observations contribute to the understanding of the evolution of SSTR family and offer information on structure, distribution and function of fish SSTRs.
Collapse
Affiliation(s)
- Dong Haiyan
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals and Guangdong Provincial Key Laboratory for Aquatic Economic Animals, Sun Yat-Sen University, Guangzhou 510275, China
| | | | | |
Collapse
|
15
|
Zhou L, Gui JF. Molecular mechanisms underlying sex change in hermaphroditic groupers. FISH PHYSIOLOGY AND BIOCHEMISTRY 2010; 36:181-193. [PMID: 20467860 DOI: 10.1007/s10695-008-9219-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2008] [Accepted: 03/30/2008] [Indexed: 05/29/2023]
Abstract
Groupers are widely distributed throughout the tropical and subtropical waters of the world and are regarded as a favourite marine food fish. However, their large-scale aquaculture has been hindered by the rarity of natural males. Being protogynous hermaphrodites, groupers have been considered as study model for development and reproduction, especially for sex determination or sex differentiation, owing to the advantage that grouper gonad development undergoes transition from ovary to intersexual gonad and then to testis, and primordial germ cells and different stages of gametic cells during oogenesis and spermatogenesis are synchronously observed in the transitional gonads. Recently, a series of genes related to the reproduction regulation or sex differentiation have been identified in the groupers, mainly by researchers in China. One important finding was that the grouper gene, doublesex/male abnormal 3-related transcription factor 1 (DMRT1), is not only differentially expressed in gonads at different stages, but that it is also restricted to specific stages and specific cells of spermatogenesis. Grouper DMRT1 protein exists only in spermatogonia, primary spermatocytes and secondary spermatocytes, but not in the supporting Sertoli cells. Moreover, no introns were found in the grouper DMRT1, and no duplicated DMRT1 genes were detected. The finding implies that the intronless DMRT1 that is able to undergo rapid transcriptional turnover might be a significant gene for stimulating spermatogenesis in the protogynous hermaphroditic gonad. Additionally, we have found that grouper expression of sex-determining region Y-related high-mobility group-box gene 3 (SOX3) is a significant time point for enterable gametogenesis of primordial germ cells, because SOX3 is obviously expressed and localized in primordial germ cells. As SOX3 continues to express, the SOX3-positive primordial germ cells develop toward oogonia and then oocytes, whereas, when SOX3 expression is ceased, the SOX3-positive primordial germ cells develop toward spermatogonia. Therefore, we suggest that SOX3, as a transcription factor, might have more important roles in oogenesis than in spermatogenesis. Based on the findings, a hypothetic molecular mechanism underlying sex change is proposed in the hermaphroditic groupers, and some candidate genes related to the grouper sex change are also suggested for further research.
Collapse
Affiliation(s)
- Li Zhou
- State Key Laboratory of Freshwater Ecology and Biotechnology, Wuhan Center for Developmental Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Graduate School of the Chinese Academy of Sciences, Wuhan 430072, China
| | | |
Collapse
|
16
|
The endocrine regulation network of growth hormone synthesis and secretion in fish: Emphasis on the signal integration in somatotropes. SCIENCE CHINA-LIFE SCIENCES 2010; 53:462-70. [DOI: 10.1007/s11427-010-0084-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Accepted: 01/06/2010] [Indexed: 01/21/2023]
|
17
|
Zhang L, Li W, Hong X, Lin H. Regulation of preprosomatostatin 1 (PSS1) gene expression by 17beta-estradiol and identification of the PSS1 promoter region in orange-spotted grouper (Epinephelus coioides). Mol Cell Endocrinol 2009; 311:87-93. [PMID: 19559750 DOI: 10.1016/j.mce.2009.06.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/26/2009] [Revised: 06/02/2009] [Accepted: 06/11/2009] [Indexed: 12/01/2022]
Abstract
In the present paper the effects of 17beta-estradiol on the expression of the preprosomatostatin 1 (PSS1) in the orange-spotted grouper hypothalamus and ovary were investigated. Results from in vivo of intraperitoneal injection and in vitro static cultures showed that estradiol increased the mRNA expression of PSS1 gene in both hypothalamus and ovary. To investigate the molecular basis of the estrogen regulation on PSS1 gene expression, we cloned the upstream region of 848bp from the translation initiation codon of the grouper PSS1 gene. The TATA-box and putative transcription factor binding sites were identified using computer analysis. Transient transfections with promoter-luciferase reporter constructs together with hER expression vector were carried out in MCF-7 cell line. The results suggest that the region from -848 to -373bp, containing five putative ERE half sites, may contribute to the promoter activity induced by estradiol. These results represent the first demonstration at the molecular level of the regulation of PSS1 gene by 17beta-estradiol in fish.
Collapse
Affiliation(s)
- Li Zhang
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animals, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, PR China
| | | | | | | |
Collapse
|
18
|
Abstract
Somatostatin and its receptors have a critical role in mammalian growth through their control pattern of secretion of growth hormone, but the evolutionary history of somatostatin and somatostatin receptors are ill defined. We used comparative whole genome analysis of Danio rerio, Carassius auratus, Xenopus tropicalis, Gallus gallus, Monodelphis domestica, Homo sapiens, Sus scrofa, Bos taurus, Mus musculus, Rattus norvegicus, Canis lupus familiaris, Ovis aries, Equus caballus, Pan troglodytes and Macaca mulatto to identify somatostatin and somatostatin receptors in each species. To date, we have identified a minimum of two genes of somatostatin and five somatostatin receptor genes in mammalian species with variable forms. We established a clear evolutionary history of the somatostatin system and traced the origin of the somatostatin system to 395 million years ago (MYA), identifying critical steps in their evolution.
Collapse
|
19
|
Molecular and expression characterization of two somatostatin genes in the Chinese sturgeon, Acipenser sinensis. Comp Biochem Physiol A Mol Integr Physiol 2009; 154:127-34. [DOI: 10.1016/j.cbpa.2009.05.012] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2009] [Revised: 05/07/2009] [Accepted: 05/19/2009] [Indexed: 11/23/2022]
|
20
|
Xu M, Volkoff H. Cloning, tissue distribution and effects of food deprivation on pituitary adenylate cyclase activating polypeptide (PACAP)/PACAP-related peptide (PRP) and preprosomatostatin 1 (PPSS 1) in Atlantic cod (Gadus morhua). Peptides 2009; 30:766-76. [PMID: 19135491 DOI: 10.1016/j.peptides.2008.12.010] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2008] [Revised: 12/09/2008] [Accepted: 12/09/2008] [Indexed: 10/21/2022]
Abstract
Full-length complementary deoxyribonucleic acid sequences encoding pituitary adenylate cyclase activating polypeptide (PACAP)/PACAP-related peptide (PRP) and preprosomatostatin 1 (PPSS 1) were cloned from Atlantic cod (Gadus morhua) hypothalamus using reverse transcription and rapid amplification of complementary deoxyribonucleic acid ends. Semi-quantitative reverse transcriptase polymerase chain reaction shows that PRP/PACAP mRNA and PPSS 1 mRNA are widely distributed throughout cod brain. During development, PRP/PACAP and PPSS 1 were detected at the 30-somite stage and pre-hatching stage, respectively, and expression levels gradually increased up to the hatched larvae. PPSS 1, but not PRP/PACAP, appeared to be affected by food availability during early development. In juvenile cod, PPSS 1 expression levels increased and remained significantly higher than that of control fed fish throughout 30 days of starvation and during a subsequent 10 days refeeding period. In contrast, PRP/PACAP expression levels were not affected by 30 days of food deprivation, but a significant increase in expression levels was observed during the 10 days refeeding period in the experimental food-deprived group as compared to the control fed group. Our results suggest that PRP/PACAP and PPSS 1 may be involved in the complex regulation of growth, feeding and metabolism during food deprivation and refeeding in Atlantic cod.
Collapse
Affiliation(s)
- Meiyu Xu
- Departments of Biology, Memorial University of Newfoundland, St John's, Canada.
| | | |
Collapse
|
21
|
|
22
|
|
23
|
Klein SE, Sheridan MA. Somatostatin signaling and the regulation of growth and metabolism in fish. Mol Cell Endocrinol 2008; 286:148-54. [PMID: 17919810 DOI: 10.1016/j.mce.2007.08.010] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2007] [Revised: 08/06/2007] [Accepted: 08/25/2007] [Indexed: 11/17/2022]
Abstract
The study of the somatostatins (SS) signaling system in fish has provided important information about the structure, function, and evolution of SSs and their receptors. The SS signaling system elicits widespread biological actions via multiple hormone variants, numerous receptor subtypes, and a variety of signal transduction pathways. SSs alter growth via both direct and indirect actions, including inhibiting growth hormone release at the pituitary, decreasing hepatic GH sensitivity, and lowering plasma IGF-I levels. Metabolism also is significantly influenced by SSs. SSs stimulate the breakdown of energy stores and influences digestion, food intake, nutrient absorption, and food conversion both directly and through the modulation of other hormonal systems. The study of fish, which display a diversity of habitat types and life history forms, reveals that the SS signaling system helps regulate energy partitioning and integrate metabolism with growth and other biological processes.
Collapse
Affiliation(s)
- Sarah E Klein
- Department of Biological Sciences, North Dakota State University, Fargo, ND 58105, USA
| | | |
Collapse
|
24
|
Tostivint H, Lihrmann I, Vaudry H. New insight into the molecular evolution of the somatostatin family. Mol Cell Endocrinol 2008; 286:5-17. [PMID: 18406049 DOI: 10.1016/j.mce.2008.02.029] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 02/26/2008] [Accepted: 02/28/2008] [Indexed: 12/11/2022]
Abstract
The present review describes the molecular evolution of the somatostatin family and its relationships with that of the urotensin II family. Most of the somatostatin sequences collected from different vertebrate species can be grouped as the products of at least four loci. The somatostatin 1 (SS1) gene is present in all vertebrate classes from agnathans to mammals. The SS1 gene has given rise to the somatostatin 2 (SS2) gene by a segment/chromosome duplication that is probably the result of a tetraploidization event according to the 2R hypothesis. The somatostatin-related peptide cortistatin, first identified in rodents and human, is the counterpart of SS2 in placental mammals. In fish, the existence of two additional somatostatin genes has been reported. The first gene, which encodes a peptide usually named somatostatin II (SSII), exists in almost all teleost species investigated so far and is thought to have arisen through local duplication of the SS1 gene. The second gene, which has been characterized in only a few teleost species, encodes a peptide also named SSII that exhibits a totally atypical structure. The origin of this gene is currently unknown. Nevertheless, because the two latter genes are clearly paralogous genes, we propose to rename them SS3 and SS4, respectively, in order to clarify the current confusing nomenclature. The urotensin II family consists of two genes, namely the urotensin II (UII) gene and the UII-related peptide (URP) gene. Both UII and URP exhibit limited structural identity to somatostatin so that UII was originally described as a "somatostatin-like peptide". Recent comparative genomics studies have revealed that the SS1 and URP genes, on the one hand, and the SS2 and UII genes, on the other hand, are closely linked on the same chromosomes, thus confirming that the SS1/SS2 and the UII/URP genes belong to the same superfamily. According to these data, it appears that an ancestral somatostatin/urotensin II gene gave rise by local duplication to a somatostatin ancestor and a urotensin II ancestor, whereupon this pair was duplicated (presumably by a segment/chromosome duplication) to give rise to the SS1-UII pair and the SS2-URP pair.
Collapse
Affiliation(s)
- Hervé Tostivint
- INSERM U413, Laboratory of Cellular and Molecular Neuroendocrinology, University of Rouen, 76821 Mont-Saint-Aignan, France
| | | | | |
Collapse
|