Comprehensive Experimental System for a Promising Model Organism Candidate for Marine Teleosts

Keishi Sakaguchi,Michio Yoneda,Michiya Matsuyama,Noriyoshi Sakai,Kanako Nakashima,Hajime Kitano

doi:10.1038/s41598-019-41468-8

Abstract

A comprehensive experimental system for Japanese anchovy, a promising candidate model organism for marine teleosts, was established. Through the design of a rearing/spawning facility that controls the photoperiod and water temperature, one-cell eggs were continuously obtained shortly after spawning throughout the rearing period. The stages of eggs are indispensable for microinjection experiments, and we developed an efficient and robust microinjection system for the Japanese anchovy. Embryos injected with GFP mRNA showed strong whole-body GFP fluorescence and the survival rates of injected- and non-injected embryos were not significantly different, 87.5% (28 in 32 embryos) and 90.0% (45 in 50 embryos), respectively. We verified that the Tol2 transposon system, which mediates gene transfer in vertebrates, worked efficiently in the Japanese anchovy using the transient transgenesis protocol, with GFP or DsRed as the reporter gene. Finally, we confirmed that genome-editing technologies, namely Transcription Activator-Like Effector Nucleases (TALEN) and Clustered Regulatory Interspaced Short Palindromic Repeats (CRISPR)/Cas9, were applicable to the Japanese anchovy. In practice, specific gene-disrupted fishes were generated in the F1 generation. These results demonstrated the establishment of a basic, yet comprehensive, experimental system, which could be employed to undertake experiments using the Japanese anchovy as a model organism for marine teleost fish.

Highlights

Freshwater facility to breed and rear freshwater model teleosts, such as zebrafish or medaka and (3) researchers often consider that the direct analysis of the targeted fish species is more appropriate
We focused on the Japanese anchovy (Engraulis japonicus) as a candidate model organism for marine teleosts, which would be easy to handle for researchers of marine teleosts
The fishes continued to spawn every day throughout the year until the end of their lives. These results clearly indicate that the spawning of the Japanese anchovy can be readily controlled by regulating the photoperiod and the water temperature

Summary

Introduction

Freshwater facility to breed and rear freshwater model teleosts, such as zebrafish or medaka and (3) researchers often consider that the direct analysis of the targeted fish species is more appropriate. We focused on the Japanese anchovy (Engraulis japonicus) as a candidate model organism for marine teleosts, which would be easy to handle for researchers of marine teleosts. The present study established a basic, yet comprehensive experimental system for a marine teleost, the Japanese anchovy. This system, which includes various methodologies to establish the Japanese anchovy as a model organism, could facilitate the field of experimental biology of marine teleosts

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