Fish embryo culture: Migration and spreading of zebrafish (Brachydanio rerio) pigmented retinal epithelium

The Last Half Century of Fish Explant and Organ Culture

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.

Development and use of retinal pigmented epithelial cell line from zebrafish (Danio rerio) for evaluating the toxicity of ultraviolet-B

Danio rerio retinal pigmented epithelial (DrRPE) cell line, derived from the RPE tissue, was established and characterized. The cells were able to grow at a wide range of temperatures from 25°C to 32°C in Leibovitz's L-15 medium. The DrRPE cell line consists of epithelial cells with a diameter of 15-19 μm. The cell line was characterized by mitochondrial 12S rRNA gene, immunocytochemical analysis, and karyotyping. DrRPE cells treated with 10 μM of all-trans-retinol for 24 h readily formed lipid droplets. DrRPE cells were irradiated with narrowband ultraviolet-B (UV-B) radiation at different time periods of 0, 10, 20, and 40 min. The cells were subsequently examined for changes in morphology, cell viability, phagocytotic activity, mitochondrial distribution, nuclei morphology, generation of reactive oxygen species, and expression of apoptotic-related genes p53 and Cas3 by quantitative polymerase chain reaction. The results demonstrate that UV-B radiation can cause a considerable decrease in DrRPE cell viability as well as in phagocytotic activity. In addition, the results demonstrate that UV-B radiation can induce the degradation of mitochondria and DNA in cultured DrRPE cells.

Differences in growth of neurons from normal and regenerated teleost spinal cord in vitro

Explants and dissociated cells from normal adult spinal cord and regenerating cord of the teleost Apteronotus albifrons were grown in vitro for periods of 8 to 12 wk. During this time the neurons showed extensive neurite outgrowth. Neurite outgrowth from tissue explants and dissociated cells of regenerated spinal cord starts sooner and is more profuse than that from normal (unregenerated) cord. Neurite outgrowth is maximized by using adhesive substrata and a high density of explants or dissociated cells. Inasmuch as Apteronotus does regenerate its spinal cord naturally after injury, whereas mammals do not, this culture system will be useful to study factors that control (permit) regeneration of spinal neurons in this adult vertebrate.

Recent applications of fish cell culture to biomedical research

Tissues of the fishes are as amenable to the techniques of modern cell culture as mammalian tissues and organs, and yet this vast resource, comprising thousands of vertebrate species, remains largely unexplored. The model systems that have been developed demonstrate the utility of fish cells as sources of special adaptations and exaggerated physiological systems. In this review, we briefly describe several of the successful models along with recent developments in fish cell culture with the hope of stimulating increased interest in the lower vertebrates as useful complements to mammalian cell culture in biomedical research. The topics covered include epithelial ion transport, endocrinological studies, the cellular stress (heat shock) response, thermotolerance, cancer biology, and environmental toxicology.