Evolutionary origin of the hypothalamic-pituitary axis in the most primitive vertebrate, hagfish

2015 Fiscal Year Final Research Report

• Project/Area Number: 25440159
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Morphology/Structure
• Research Institution: University of Miyazaki
• Principal Investigator: Uchida Katsuhisa 宮崎大学, 農学部, 准教授 (50360508)
• Co-Investigator(Kenkyū-buntansha): Shunsuke Moriyama 北里大学, 海洋生命科学部, 教授 (50222352)
• Co-Investigator(Renkei-kenkyūsha): Susumu Hyodo 東京大学, 大気海洋研究所, 准教授 (40222244)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 下垂体 / ホルモン / 無顎類 / 進化

Outline of Final Research Achievements

Here we report the identification of a growth hormone (GH) from the pituitary of the Pacific hagfish (Eptatretus burgeri) by next-generation sequence analysis. The hagfish GH cDNA consists of 870 nucleotides encoding a prehormone of 203 amino acid (aa) residues, with a putative signal peptide of 20 aa residues and a mature protein of 183 aa residues. By aligning cysteine (Cys) residues, the aa sequence was comparable to gnathostome GHs; four Cys were conserved at position 75, 177, 194, 204, which have been considered to be crucial for molecular construction of GH.
For immunohistochemistry, a rabbit antiserum was raised against the synthetic peptides corresponding to the hagfish pre-GH (aa 109-122). An intense immunoreaction to anti-hagfish GH was observed in peripheral cells of most cell clusters in the adenohypophysis. We are now analyzing the cellular localization of GH gene and functions of GH molecule in the Pacific hagfish.

Free Research Field

生物学