Fish Physiology and Biochemistry

, Volume 44, Issue 3, pp 829–839 | Cite as

Spexin in the half-smooth tongue sole (Cynoglossus semilaevis): molecular cloning, expression profiles, and physiological effects

  • Shengpeng Wang
  • Bin Wang
  • Songlin Chen


Spexin (SPX), a novel neuropeptide discovered by the bioinformatics approach, has been shown to exert pleiotropic functions in mammals. However, little information regarding the physiological role of SPX is available in teleosts. As a first step, we cloned the spexin gene from a flatfish, the half-smooth tongue sole. The open reading frame (ORF) of tongue sole spexin contained 363 nucleotides encoding a 120 amino acid (aa) preprohormone with a calculated molecular mass and isoelectric point of 14.06 kDa and 5.86, respectively. The tongue sole SPX precursor contained a 27 aa signal peptide and a 14 aa mature peptide flanked by two dibasic protein cleavage sites (RR and GRR). Tissue distribution analysis showed that spexin mRNA could be detected in various tissues, notably in the brain. In addition, fasting stimulated the hypothalamic expression of spexin mRNA. Intraperitoneal injection of SPX increased gnih and gnrh3 mRNA levels in the hypothalamus; however, SPX inhibited the pituitary expression of gh, fshβ, and gthα mRNAs. Overall, our results reveal the existence of a functional SPX in the tongue sole, which could represent an important factor in the neuroendocrine control of flatfish reproduction and growth, and the spexin mRNA expression is regulated by feeding status.


Spexin cDNA cloning Fasting Cynoglossus semilaevis 



This work was supported by grants from the National Natural Science Foundation of China (31530078, 31730099, and 31602133), AoShan Talents Cultivation Program supported by Qingdao National Laboratory for Marine Science and Technology (No. 2017ASTCP-OS15), Taishan Scholar Climbing Project of Shandong, and the China Agriculture Research System (CARS-47).


  1. Chen S, Zhang G, Shao C, Huang Q, Liu G, Zhang P, Song W, An N, Chalopin D, Volff JN, Hong Y, Li Q, Sha Z, Zhou H, Xie M, Yu Q, Liu Y, Xiang H, Wang N, Wu K, Yang C, Zhou Q, Liao X, Yang L, Hu Q, Zhang J, Meng L, Jin L, Tian Y, Lian J, Yang J, Miao G, Liu S, Liang Z, Yan F, Li Y, Sun B, Zhang H, Zhang J, Zhu Y, Du M, Zhao Y, Schartl M, Tang Q, Wang J (2014) Whole-genome sequence of a flatfish provides insights into ZW sex chromosome evolution and adaptation to a benthic lifestyle. Nat Genet 46(3):253–260. CrossRefPubMedGoogle Scholar
  2. Gu L, Ma Y, Gu M, Zhang Y, Yan S, Li N, Wang Y, Ding X, Yin J, Fan N, Peng Y (2015) Spexin peptide is expressed in human endocrine and epithelial tissues and reduced after glucose load in type 2 diabetes. Peptides 71:232–239. CrossRefPubMedGoogle Scholar
  3. Ji XS, Chen SL, Jiang YL, Xu TJ, Yang JF, Tian YS (2011a) Growth differences and differential expression analysis of pituitary adenylate cyclase activating polypeptide (PACAP) and growth hormone-releasing hormone (GHRH) between the sexes in half-smooth tongue sole Cynoglossus semilaevis. Gen Comp Endocrinol 170(1):99–109. CrossRefPubMedGoogle Scholar
  4. Ji XS, Liu HW, Chen SL, Jiang YL, Tian YS (2011b) Growth differences and dimorphic expression of growth hormone (GH) in female and male Cynoglossus semilaevis after male sexual maturation. Mar Genomics 4(1):9–16. CrossRefPubMedGoogle Scholar
  5. Kim DK, Yun S, Son GH, Hwang JI, Park CR, Kim JI, Kim K, Vaudry H, Seong JY (2014) Coevolution of the spexin/galanin/kisspeptin family: spexin activates galanin receptor type II and III. Endocrinology 155(5):1864–1873. CrossRefPubMedGoogle Scholar
  6. Li S, Liu Q, Xiao L, Chen H, Li G, Zhang Y, Lin H (2016) Molecular cloning and functional characterization of spexin in orange-spotted grouper (Epinephelus coioides). Comp Biochem Physiol B Biochem Mol Biol 196-197:85–91. CrossRefPubMedGoogle Scholar
  7. Lin CY, Zhang M, Huang T, Yang LL, Fu HB, Zhao L, Zhong LL, Mu HX, Shi XK, Leung CF, Fan BM, Jiang M, Lu AP, Zhu LX, Bian ZX (2015) Spexin enhances bowel movement through activating L-type voltage-dependent calcium channel via galanin receptor 2 in mice. Sci Rep 5(12095)Google Scholar
  8. Liu Y, Li S, Qi X, Zhou W, Liu X, Lin H, Zhang Y, Cheng CH (2013) A novel neuropeptide in suppressing luteinizing hormone release in goldfish, Carassius auratus. Mol Cell Endocrinol 374(1-2):65–72. CrossRefPubMedGoogle Scholar
  9. Ma A, He M, Bai J, Wong MK, Ko WK, Wong AO (2017) Dual role of insulin in spexin regulation: functional link between food intake and spexin expression in a fish model. Endocrinology 158(3):560–577. PubMedCrossRefGoogle Scholar
  10. Mirabeau O, Perlas E, Severini C, Audero E, Gascuel O, Possenti R, Birney E, Rosenthal N, Gross C (2007) Identification of novel peptide hormones in the human proteome by hidden Markov model screening. Genome Res 17(3):320–327. CrossRefPubMedPubMedCentralGoogle Scholar
  11. Moazen P, Taherianfard M, Ahmadi Soleimani M, Norozpor M (2017) Synergistic effect of spexin and progesterone on pain sensitivity attenuation in ovariectomized rats. Clin Exp Pharmacol Physiol.
  12. Munoz-Cueto JA, Paullada-Salmeron JA, Aliaga-Guerrero M, Cowan ME, Parhar IS, Ubuka T (2017) A journey through the gonadotropin-inhibitory hormone system of fish. Front Endocrinol (Lausanne) 8(285)Google Scholar
  13. Porzionato A, Rucinski M, Macchi V, Stecco C, Malendowicz LK, De Caro R (2010) Spexin expression in normal rat tissues. J Histochem Cytochem 58(9):825–837. CrossRefPubMedPubMedCentralGoogle Scholar
  14. Porzionato A, Rucinski M, Macchi V, Stecco C, Sarasin G, Sfriso MM, Di Giulio C, Malendowicz LK, De Caro R (2012) Spexin is expressed in the carotid body and is upregulated by postnatal hyperoxia exposure. Adv Exp Med Biol 758:207–213. CrossRefPubMedGoogle Scholar
  15. Rucinski M, Porzionato A, Ziolkowska A, Szyszka M, Macchi V, De Caro R, Malendowicz LK (2010) Expression of the spexin gene in the rat adrenal gland and evidences suggesting that spexin inhibits adrenocortical cell proliferation. Peptides 31(4):676–682. CrossRefPubMedGoogle Scholar
  16. Sonmez K, Zaveri NT, Kerman IA, Burke S, Neal CR, Xie X, Watson SJ, Toll L (2009) Evolutionary sequence modeling for discovery of peptide hormones. PLoS Comput Biol 5(1):e1000258. CrossRefPubMedPubMedCentralGoogle Scholar
  17. Tamura K, Stecher G, Peterson D, Filipski A, Kumar S (2013) MEGA6: Molecular Evolutionary Genetics Analysis version 6.0. Mol Biol Evol 30:2725–2729CrossRefPubMedPubMedCentralGoogle Scholar
  18. Toll L, Khroyan TV, Sonmez K, Ozawa A, Lindberg I, McLaughlin JP, Eans SO, Shahien AA, Kapusta DR (2012) Peptides derived from the prohormone proNPQ/spexin are potent central modulators of cardiovascular and renal function and nociception. FASEB J 26(2):947–954. CrossRefPubMedPubMedCentralGoogle Scholar
  19. Tsutsui K, Ubuka T, Son YL, Bentley GE, Kriegsfeld LJ (2015) Contribution of GnIH research to the progress of reproductive neuroendocrinology. Front Endocrinol (Lausanne) 6(179)Google Scholar
  20. Ubuka T, Son YL, Tsutsui K (2016) Molecular, cellular, morphological, physiological and behavioral aspects of gonadotropin-inhibitory hormone. Gen Comp Endocrinol 227:27–50. CrossRefPubMedGoogle Scholar
  21. Volkoff H, Canosa LF, Unniappan S, Cerda-Reverter JM, Bernier NJ, Kelly SP, Peter RE (2005) Neuropeptides and the control of food intake in fish. Gen Comp Endocrinol 142(1-2):3–19. CrossRefPubMedGoogle Scholar
  22. Walewski, J.L., Ge, F., Lobdell, H.t., Levin, N., Schwartz, G.J., Vasselli, J.R., Pomp, A., Dakin, G., Berk, P.D., 2014. Spexin is a novel human peptide that reduces adipocyte uptake of long chain fatty acids and causes weight loss in rodents with diet-induced obesity. Obesity (Silver Spring) 22, 1643–1652, 7, DOI:
  23. Wang B, Jia J, Yang G, Qin J, Zhang C, Zhang Q, Sun C, Li W (2016) In vitro effects of somatostatin on the growth hormone-insulin-like growth factor axis in orange-spotted grouper (Epinephelus coioides). Gen Comp Endocrinol 237:1–9. CrossRefPubMedGoogle Scholar
  24. Wang B, Liu Q, Liu X, Xu Y, Shi B (2017a) Molecular characterization of Kiss2 receptor and in vitro effects of Kiss2 on reproduction-related gene expression in the hypothalamus of half-smooth tongue sole (Cynoglossus semilaevis). Gen Comp Endocrinol 249:55–63. CrossRefPubMedGoogle Scholar
  25. Wang B, Liu Q, Liu X, Xu Y, Shi B (2018) Molecular characterization and expression profiles of LPXRFa at the brain-pituitary-gonad axis of half-smooth tongue sole (Cynoglossus semilaevis) during ovarian maturation. Comp Biochem Physiol B Biochem Mol Biol 216:59–68. CrossRefPubMedGoogle Scholar
  26. Wang B, Liu Q, Liu X, Xu Y, Song X, Shi B (2017b) Molecular characterization of kiss2 and differential regulation of reproduction-related genes by sex steroids in the hypothalamus of half-smooth tongue sole (Cynoglossus semilaevis). Comp Biochem Physiol A Mol Integr Physiol 213:46–55. CrossRefPubMedGoogle Scholar
  27. Wang B, Liu X, Liu Q, Zhao M, Xu Y, Shi B (2017c) Molecular cloning, localization, and expression analysis of gnrh2 in different tissues of half-smooth tongue sole (Cynoglossus semilaevis) during ovarian maturation. Prog Fish Sci 38:63–72Google Scholar
  28. Wang B, Qin C, Zhang C, Jia J, Sun C, Li W (2014) 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 382(2):851–859. CrossRefPubMedGoogle Scholar
  29. Wong MK, Sze KH, Chen T, Cho CK, Law HC, Chu IK, Wong AO (2013) Goldfish spexin: solution structure and novel function as a satiety factor in feeding control. Am J Physiol Endocrinol Metab 305(3):E348–E366. CrossRefPubMedGoogle Scholar
  30. Wu H, Lin F, Chen H, Liu J, Gao Y, Zhang X, Hao J, Chen D, Yuan D, Wang T, Li Z (2016) Ya-fish (Schizothorax prenanti) spexin: identification, tissue distribution and mRNA expression responses to periprandial and fasting. Fish Physiol Biochem 42(1):39–49. CrossRefPubMedGoogle Scholar
  31. Yang G, Qin C, Wang B, Jia J, Yuan X, Sun C, Li W (2017) Molecular identification and functional analysis of Ctrp9 in Epinephelus coioides. J Mol Endocrinol 58(4):179–191. CrossRefPubMedGoogle Scholar
  32. Zhang C, Sun C, Wang B, Yan P, Wu A, Yang G, Li W (2016) Orexin-A stimulates the expression of GLUT4 in a glucose dependent manner in the liver of orange-spotted grouper (Epinephelus coioides). Comp Biochem Physiol A Mol Integr Physiol 199:95–104. CrossRefPubMedGoogle Scholar
  33. Zheng B, Li S, Liu Y, Li Y, Chen H, Tang H, Liu X, Lin H, Zhang Y, Cheng CHK (2017) Spexin suppress food intake in zebrafish: evidence from gene knockout study. Sci Rep 7(14643):14643. CrossRefPubMedPubMedCentralGoogle Scholar
  34. Zhou X, Yi Q, Zhong Q, Li C, Muhammad S, Wang X, Wang Z, Qi J, Yu H, Zhang Q (2012) Molecular cloning, tissue distribution, and ontogeny of gonadotropin-releasing hormone III gene (GnRH-III) in half-smooth tongue sole (Cynoglossus semilaevis). Comp Biochem Physiol B Biochem Mol Biol 163(1):59–64. CrossRefPubMedGoogle Scholar
  35. Zohar Y, Munoz-Cueto JA, Elizur A, Kah O (2010) Neuroendocrinology of reproduction in teleost fish. Gen Comp Endocrinol 165(3):438–455. CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media B.V., part of Springer Nature 2018

Authors and Affiliations

  1. 1.Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, Yellow Sea Fisheries Research InstituteChinese Academy of Fishery SciencesQingdaoChina
  2. 2.Laboratory for Marine Fisheries and Food Production ProcessesQingdao National Laboratory for Marine Science and TechnologyQingdaoChina

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