The molecular mechanism underlying the acquisition of novel traits by focusing on the evolution of hairs to spines in mammals

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K19422
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Research Field: Ecology and Evolution (including anthropology), and related fields
• Research Institution: Tokyo Institute of Technology
• Principal Investigator: Nikaido Masato 東京工業大学, 生命理工学院, 准教授 (70432010)
• Co-Investigator(Kenkyū-buntansha): 岡部 正隆 東京慈恵会医科大学, 医学部, 教授 (10300716) ; 重谷 安代 東京慈恵会医科大学, 医学部, 講師 (70431773)
• Project Period (FY): 2017-06-30 – 2020-03-31
• Keywords: ハリネズミ / 針 / 体毛 / パラフィン切片 / RNAseq / 平行進化

Outline of Final Research Achievements

The main objectives of this study are 1. to examine whether the spines of hedgehogs are a fusion of multiple hairs or an enlargement of one hair, and 2. to exhaustively explore the genes that contribute to the morphological fifferences between spines and hairs by using RNAseq technique. Microscopic observation of paraffin sections of spines and hairs showed that the base of the needles had a single structure of papillary cell region, implying that the spines developmentally originate from a single hair. Subsequent RNAseq results on spines and hairs indicated that specific keratin and keratin-related protein genes were expressed in the spine region, that may be involved in the hard and characteristic internal structure and of spines.

Free Research Field

進化生物学

Academic Significance and Societal Importance of the Research Achievements

ハリネズミは研究者だけでなく一般の人々にとってもよく知られた生き物であるにもかかわらず、その針の発生学的起源に関しては意外にも知られていなかった。また、ハリネズミだけでなく多くの哺乳類において観察される体毛の針化は平行進化を理解するための好例である。この体毛の針化メカニズムの一端を明らかにした本成果は学術的・社会的な意義は大きいと感じている。