The Last Half Century of Fish Explant and Organ Culture

Abstract

Explants are three-dimensional tissue fragments maintained outside the organism. The goals of this article are to review the history of fish explant culture and discuss applications of this technique that may assist the modern zebrafish laboratory. Because most zebrafish workers do not have a background in tissue culture, the key variables of this method are deliberately explained in a general way. This is followed by a review of fish-specific explantation approaches, including presurgical husbandry, aseptic dissection technique, choice of media and additives, incubation conditions, viability assays, and imaging studies. Relevant articles since 1970 are organized in a table grouped by organ system. From these, I highlight several recent studies using explant culture to study physiological and embryological processes in teleosts, including circadian rhythms, hormonal regulation, and cardiac development.

Keywords: cell culture; explant; media; organ culture; organoid; slice culture; tissue culture.

FIG. 1.

Pathways from in vivo to in vitro. Starting with a fish, a tissue explant or slice is prepared. Historically, the purpose of the explant was to outgrow primary cells. Surviving cells were then passaged repeatedly, establishing permanent or “immortal” cell lines. Although convenient to manipulate, immortal cells may differ phenotypically and genetically from in vivo or primary cells, and represent only a fraction of the explant from which they were derived. 3D, three dimensional.

FIG. 2.

Selected explant culture supports. For clarity, components are not necessarily shown to scale.

FIG. 3.

Adventures in fish explant culture. (A) Lazado et al. (B) Bloch et al. (C) Yue et al. For descriptions, see text.