Developmental study of vertebrate jaw evolution by using shark embryos

2014 Fiscal Year Final Research Report

• Project/Area Number: 24770217
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Developmental biology
• Research Institution: Tokyo Medical and Dental University (2013-2014); Iwate Medical University (2012)
• Principal Investigator: MASAKI Takechi 東京医科歯科大学, 医歯(薬)学総合研究科, テニュアトラック助教 (10455355)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 顎 / 形態進化 / トラザメ / 軟骨魚類 / 鰓弓 / 咽頭弓 / 鼓膜 / 中耳

Outline of Final Research Achievements

To elucidate the developmental basis of jaw patterning in the vertebrate evolution, I tried to examine jaw development in the shark embryo (Scyliorhinus torazame). I isolated genes that are considered to be involved in jaw patterning in the shark, and examined expression pattern of these genes in shark embryos. Expression pattern of Dlx1-6 genes suggest that jaw patterning along the dorsal-ventral axis in the shark is established by Dlx-code as in the other jawed vertebrates. I also compared expression pattern of Bapx1 gene in the mouse, chick and shark, and found that the position of the expression shifted dorsally in the mammalian lineage. We suggest that this developmental event led to tympanic membrane formation in the lower jaw region in a mammalian ancestor.

Free Research Field

進化発生学