Molecular evolution of seminal plasma protein in Tanganyikan cichlids

• Project/Area Number: 25840130
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Evolutionary biology
• Research Institution: University of the Ryukyus
• Principal Investigator: MORITA Masaya 琉球大学, 熱帯生物圏研究センター, 准教授 (80535302)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Project Status: Completed (Fiscal Year 2014)
• Budget Amount: ¥4,550,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥1,050,000); Fiscal Year 2014: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2013: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
• Keywords: 受精 / 生殖行動 / 精しょうタンパク質 / 分子進化 / 精子競争 / シクリッド / 種分化 / 産卵行動 / 精子

Outline of Final Research Achievements

Tanganyikan cichlids show variety rich reproductive behavior and also distinctive fertilization manners. Those fertilization manners were categorized into 3 types, oral fertilization, substrate fertilization, and stocked-sperm fertilization. Among those manners, only oral fertilization manner favors aggregation and immobilization of sperm. The seminal plasma protein 120 named SPP120 is suggested to function as a immobilization and aggregation of sperm. In this project, I investigated the relationship between fertilization manners and evolution of SPP120 in terms of molecular sequence evolution and glycosylation. The expressed SPP120 immobilized sperm motility and aggregated sperm. Furthermore, glycosylation enhanced aggregation of sperm via increase in viscosity of semen and PGLS analyses suggested the evolutionary correlation with oral fertilization manner. Those results indicated that SPP120 evolved in response to the changes in fertilization manners.

Research Products

• [Journal Article] Bower-building behaviour is associated with increased sperm longevity in Tanganyikan cichlids. (2014)
  • Author(s): Morita, M., Awata, S., Yorifuji, M., Ota, K., Kohda, M. & Ochi, H.
  • Journal Title: Journal of Evolutionary Biology Volume: 27 Issue: 12 Pages: 2629-2643
  • DOI: 10.1111/jeb.12522
  • Peer Reviewed / Acknowledgement Compliant
• [Journal Article] Sneaker males are not necessarily similar to females in colour in a sexually monochromatic cichlid (2013)
  • Author(s): Ota, K., Awata, S., Morita, M., & Kohda, M.
  • Journal Title: Journal of Zoology Volume: (Print ISSN 0952-8369) Issue: 1 Pages: 63-70
  • DOI: 10.1111/jzo.12125
  • Peer Reviewed
• [Presentation] 精しょうタンパク質SPP120と生殖行動の関係 (2013)
  • Author(s): 守田昌哉
  • Organizer: 日本動物学会
  • Place of Presentation: 岡山大学