A new development of prolactin research to understanding the origin and multi-functionalization

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K14766
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Morphology/Structure
• Research Institution: The University of Tokyo
• Principal Investigator: HYODO SUSUMU 東京大学, 大気海洋研究所, 准教授 (40222244)
• Co-Investigator(Kenkyū-buntansha): 岡田 令子 静岡大学, 理学部, 講師 (50386554) ; 鈴木 雅一 静岡大学, 理学部, 教授 (60280913)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: プロラクチン / 軟骨魚類 / 両生類 / 脳下垂体 / 環境適応 / 変態

Outline of Final Research Achievements

The aim of this study is to understanding origin and evolution of pituitary hormone, prolactin (PRL). Genome and transcriptome analyses revealed that PRL and its specific receptor exist in elasmobranchs, suggesting that duplication and subsequent diversification of the growth hormone/PRL family already occurred when the cartilaginous fish lineage diverged. The cells expressing PRL receptor located close to the PRL-producing cells in the rostral pars distalis of pituitary of juvenile bull shark, implying that one of the original functions of PRL is paracrine control of pituitary function. Meanwhile, in the bullfrog, PRL1B, which is the orthologue of fish PRL, showed high expression in the pituitary of pre-metamorphic tadpoles, while tetrapod-type PRL1A, which is duplicated from the PRL1B gene, was highly expressed in the metamorphic tadpole and adult pituitaries. These achievements offer new insights into molecular and functional evolution of multifunctional PRL in vertebrates.

Free Research Field

魚類生理学、比較内分泌学