Nutritional Requirements for Reproduction of a Temperature Sensitive Nematode,Reared in Axenic Culture. ∗ †

Abstract

Summary

1. Temperature-sensitivity in C. clegans Bergerac is a complex system, composed of a combination of factors, i.e., a) the production of an inhibitory factor in response to higher temperatures, and b) nutritional requirements consisting of proper mineral balance and certain vitamins. 2. Temperature-sensitivity can be overcome by growing the worms at 17°C in 50% heated liver extract + 30% partially defined (peptone) medium and heat-treating them at 27°C for 27 hours in distilled water or in cold blooded Ringers solution. Worms grown in 50% liver extract + water and heat-shocked in distilled water do not reproduce. Deletion and addition of groups of nutrients to the medium indicates that both vitamins and salts are required for protection against heat-shock in distilled water. 3. The need for extra vitamins is eliminated when the worms are grown at 17°C in 50% liver extract + water and heat-shocked in Ringers solution. Comparison of the salts in the peptone medium and Ringers solution suggests that either Na⁺ or (less likely) HCO₃ ⁻ could be responsible for protection against higher temperatures.