Effects of temperature on reptilian and other cells

Abstract

Reptilian cells, whether from adult organs or from entire embryos, may be cultured satisfactorily in Medium 199, to which is added 20 % foetal-calf serum. This medium, used at normal strength, is adequate even for the maintenance and proliferation of kidney and liver cells from an amphibian tadpole, but the performance of cells of lower vertebrates in the medium is inferior to that of mammalian and avian cells. When cultured for periods of at least 2 days, avian cells survive in an apparently normal fashion at higher temperatures (maximal, 45 °C) than reptilian; reptilian cells at higher temperatures than mammalian; and mammalian cells at higher temperatures than amphibian. There is a close correspondence between the lethal high temperatures of embryonic cells of diurnal lizards in culture (42-43 °C) and the known heatdeath temperatures of adult animals. Although inactive and contracted in culture at 3 °C, reptilian, avian and mammalian cells remain viable, often for prolonged periods without change of medium. The optimal temperature for cell culture is in the vicinity of 37·5 °C for reptilian, avian and mammalian cells, and about 31·5 °C for the amphibian cells used. Different types of cells from the same animal may have different temperature ranges. Epithelioid cells, for example, function better at higher temperatures than fibroblasts and in some cases may be shown to have a slightly higher maximal temperature. Dissociated epithelioid cells in culture may adopt a fibroblast-type of morphology, wandering on the glass surface with extended processes, or they may come together with other similar cells to form epithelial sheets. Fibroblasttype cells may contribute to monolayer formation, but do not join with epithelioid cells to form epithelial sheets.