Dr. Rie GOTO (Ehime University)

2016. 08. 22 (Mon) 16:30 ~ 17:30

Conference Room, NIBB (Myodaiji)

Laboratory of Bioresources, Yusuke Takehana (7579)

The 9th NIBB International Practical Course

The 4th NIBB-TLL Joint International Practical Course

Open Seminar

Development of “the Next-Generation Breeding System” for suma, Euthynnus affinis

In our laboratory, we have started developing “the Next-Generation Breeding System (NGBS)” for preserving good strains of suma, Euthynnus affinis. Suma belongs to the Scombridae family and is genetically related to bluefin tuna. Since 2012, we have been investigating suma to introduce this as a new farming species in Ehime.
 

In tuna species, techniques required for traditional subculturing for aquaculture, such as artificial fertilization and one to one cross breeding, are methods in theory but not in practice since fish handling can cause the fish intolerable damage. NGBS will overcome these difficulties and be able to provide fish with catalogue ordered gametes through cryopreserved germ cells while avoiding breed deterioration. This system allows us to restore the strains through germline chimeras only when necessary. The goal of our project is to develop a workable process for a breeding system suitable for suma in parallel with selective breeding.
 

NGBS is based on the concept of “surrogate propagation in fish” which is a technique for production of target gametes through germline chimeras. A series of techniques to achieve “surrogate propagation” such as 1) isolation and visualization of donor germ cells, 2) sterilization of host fish, 3) production of germline chimeras and 4) cryopreservation of donor germ cells. These techniques have been mainly developed in fresh-water species including zebrafish and medaka, but partially in marine species. Germline chimeras produced by transplantation of donor germ cells provide only donor-derived gametes when the host is completely sterilized. To develop NGBS in suma, we need to solve a problem unique to marine species.
 

In this seminar, parts of NGBS for suma, gene transfer into fertilized eggs, sterilization of the host by gene knockdown, production of germline chimeras, development of host strains by genome editing are discussed.