Role of commensal bacteria in the switch of reproductive modes of planarians

2015 Fiscal Year Final Research Report

• Project/Area Number: 25650103
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Morphology/Structure
• Research Institution: Tsuyama National College of Technology
• Principal Investigator: MAEZAWA TAKANOBU 津山工業高等専門学校, その他部局等, 准教授 (90548398)
• Co-Investigator(Renkei-kenkyūsha): KAZUYA KOBAYASHI 弘前大学, 農学生命科学部, 准教授 (50360110)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: プラナリア / 生殖様式転換 / 共生細菌

Outline of Final Research Achievements

In the process of conversion from asexual to sexual reproduction (sexual induction), hermaphroditic sexual organs are gradually developed in the planarian Dugesia ryukyuensis. Tryptophan (Trp) has been identified as an inducing factor of ovary, which is firstly developed during the sexual induction. Sexual planarians contain higher concentration of Trp than that of asexual planarians. We expected that symbiotic bacteria are concerned with increasing concentration of Trp, an essential amino acid, during sexual induction. In this study, the experiment of treatment of an antibiotic suggested that the bacteria are required for ovarian development at the initial step of sexual induction. Moreover, by comparing bacteria species between asexual and sexual planarians, we found that the rate of a particular bacterium become increased during sexual induction.

Free Research Field

発生・生殖生物学