Kashima Makoto (Department of Chemistry and Biological Science, College of Science and Engineering, Brain Science Research Laboratory) made a presentation on the determination of gender in zebrafish tropical fish, at the 54th Annual Meeting of the Japanese Society of Developmental Biologists held online on Thursday, June 17 to Friday, June 18, 2021, and received the Best Oral Presentation Award.

The Japanese Society of Developmental Biologists was established in 1968 and has enjoyed a long history of more than half a century. The Society consists of various researchers covering everything from the basics to advanced applications.

The gender of mammals, including humans, is determined only by the genetic factor of the presence or absence of the Y chromosome. For some reptiles and fish, gender is influenced by temperature and nutritional status at an early stage, and environmental factors are found to be as important as genetic factors. However, its molecular entity was still unknown.

In particular, research in zebrafish had not advanced because there is no apparent gender difference at the time of sex determination.

Constructing a new methodology, Assistant Professor Kashima was able to classify zebrafish in the sex determination process into individuals that become female and individuals that become males based on the gene expression profile; by combining the technique of RNA-Seq, which acquires large amounts of gene expression data, with methods of machine-learning.

Furthermore, by focusing on the gene expression information of the individual in which sex divergence is about to occur, Assistant Professor Kashima found a candidate for a gene that responds to the environment and determines the sex.

In addition to the fundamental biological importance of the mechanism of molecules determining sex, the high versatility of the developmental methods combining biology and informatics as well as the easily understood presentation were both recognized. The presentation was chosen for the Best Oral Presentation Award from among approximately 160 titles.



Presentation Meeting: 54th Annual Meeting of the Japanese Society of Developmental Biologists.

Presentation Title: Time-course individual RNA-Seq revealed a transcriptomic landscape of environmental sex determination in zebrafish.

Presenters: Kashima Makoto, Nishimura Kanako, Hirata Hiromi.