Zoological Research ›› 2019, Vol. 40 ›› Issue (3): 185-197.doi: 10.24272/j.issn.2095-8137.2018.052

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Duplication and diversification of insulin genes in ray-finned fish

David M. Irwin1,2,*   

  1. 1. Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto Ontario M5S 1A8, Canada
    2. Banting and Best Diabetes Centre, University of Toronto, Toronto Ontario M5S 1A8, Canada
  • Received:2018-05-07 Accepted:2018-08-06 Online:2019-05-18 Published:2019-04-19
  • Contact: David M. Irwin E-mail:david.irwin@utoronto.ca

Abstract: Insulin is a key hormone for the regulation of metabolism in vertebrates. Insulin is produced by pancreatic islet cells in response to elevated glucose levels and leads to the uptake of glucose by tissues such as liver and adipose tissue to store energy. Insulin also has additional functions in regulating development. Previous work has shown that the proglucagon gene, which encodes hormones counter regulating insulin, is duplicated in teleost fish, and that the peptide hormones encoded by these genes have diversified in function. I sought to determine whether similar processes have occurred to insulin genes in these species. Searches of fish genomes revealed an unexpected diversity of insulin genes. A triplication of the insulin gene occurred at the origin of teleost fish, however one of these three genes, insc, has been lost in most teleost fish lineages. The two other insulin genes, insa and insb, have been retained but show differing levels of selective constraint suggesting that they might have diversified in function. Intriguingly, a duplicate copy of the insa gene, which I named insab, is found in many fish. The coding sequence encoded by insab genes is under weak selective constraint, with its predicted protein sequences losing their potential to be processed into a two-peptide hormone. However, these sequences have retained perfectly conserved cystine residues, suggesting that they maintain insulin’s three-dimensional structure and therefore might modulate the processing and secretion of insulin produced by the other genes.

Key words: Insulin, Teleost fish, Gene duplication, Adaptive evolution, Gene loss

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[1] CHEN Yi,TANG Jue. Studies on Colony structure and Life Cycle of The Spined ant,Polyrhchis Vicina Roger[J]. Zoological Research, 1989, 10(1): 57 -63 .
[2] YANG Da-tong,LI Si-min. A New Species of the Genus Rana From Yunnan[J]. Zoological Research, 1980, 1(2): 261 -264 .
[3] FENG Yan. Studies on The Calypterate flies in West Sichuan,China.Ⅳ.Preliminary observation on The Diurnal and Nocturnal Activity of Musca domestica Linnaeus in Yaan[J]. Zoological Research, 1989, 10(1): 65 -69 .
[4] DING Fang-mei,SHI Hong-wen,HUANG Yuan. Complete Mitochondrial Genome and Secondary Structures of lrRNA and srRNA of Atractomorpha sinensis (Orthoptera, Pyrgomorphidae)[J]. Zoological Research, 2007, 28(6): 580 -588 .
[5] DAI Qiang,GU Hai-jun ,,WANG Yue-zhao. Theories and Models for Habitat Selection[J]. Zoological Research, 2007, 28(6): 681 -688 .
[6] LIU Jing-yuan,DU Hong,TIAN Geng-bai,YU Pin-hong,WANG Shen-wen,PEN Hong. Community Structure and Diversity Distributions of Small Mammals in Different Sample Plots in the Eastern Part of Wuling Mountains[J]. Zoological Research, 2008, 29(6): 637 -645 .
[7] LIU Shu-bai ,HE Ying-ying ,QIAN Jin-qiao ,,LEE Wen-hui,ZHANG Yun. Research Progression of Non-lens βγ-crystallins[J]. Zoological Research, 2008, 29(6): 679 -688 .
[8] KONG De-jun,YANG Xiao-jun,ZHONG Xing-yao,DAO Mei-biao,ZHU Yong. Diurnal Time Budget and Behavior Rhythm of Wintering Black-necked Crane (Grus nigricollis) at Dashanbao in Yunnan[J]. Zoological Research, 2008, 29(2): 195 -202 .
[9] ZHOU Wei,LIU Zhao,WU Fei. Growth and Synchrony of Reproductive Organs in Males and Females of Rana pleuraden in Kunming Area, Yunnan[J]. Zoological Research, 2009, 30(1): 99 -104 .
[10] LI Cao,WEN Tao,GUO Peng. Pseudoxenodon stejnegeri: A New Snake Record in Yunnan Province[J]. Zoological Research, 2009, 30(1): 90 -104 .