2014 年 24 巻 2 号 p. 9-14
Medaka (Oryzias latipes) is an old but new model animal in the life sciences. Recently, numerous mutants have been produced in which orthologs of human disease genes have been knocked out. These new human disease models require methods for examining the whole-body histology of the mutant medaka. We therefore serially sectioned the whole body of adult medaka to microscopically examine all of the tissues and organs at the cellular level, and to identify any abnormalities resulting from gene knockout. In order to promote discussion of the histological and pathological findings, virtual slides of the serial whole-body sections of the medaka were prepared and shared among the authors via the internet. We also developed a tracking system with which to digitize the movements of the medaka over a 24- hour period. The system can be used to accurately clarify the circadian rhythms of medaka. We consider that the whole body sectioning and the 24-hour tracking system will be useful for comprehensively examining disease-gene knockout in medaka, and that the methods described here may open a new field of research examining the global relationships between gene functioning and physiological significance.