Temperature response in cold tolerance of C. elegans

The world is rapidly heating. As this century progresses, the effects of global warming will be ever more keenly felt. The global average temperature is set to rise by between 1.8 and 4oC. This will have a massive impact on the planet in a variety of different ways. Many parameters have been analysed: from sea level rises and changes in weather systems to desertification and food shortages. However, an often under-appreciated aspect of temperature change is the direct impact different temperatures will have on animals and plants. Individual species react differently to different temperatures. The biochemistry of how certain temperatures are tolerated is often well-known. For example, a common mechanism for dealing with cold is to increase the amount of unsaturated fatty acids in the cell membrane. This allows the membrane to maintain essential fluidity, even at freezing temperatures. What is less well established is how these changes are regulated at a genetic, cellular and whole organism level.

Reaction to temperature changes must include the whole of the organism. If not, only certain tissues and organs would respond, whereas organs would be totally unprepared for the change. Equally, it is useful for an organism to store information as to which temperatures yielded the environment most conducive to growth.

C. elegans is a tiny worm (<1mm) that is an established model organism for animal studies due to the combination of its simplicity – it has 959 cells including 302 neurons – and the fact the species has many features conserved across many animals, including humans. These desirable traits are also combined with extensive knowledge of how to manipulate the genetics of C. elegans. These factors make it ideal for studying features that are considered fundamental to an animal species’ survival. Temperature sensing and tolerance is one of those key features. In order to investigate cold tolerance, Kuhara has been developing novel techniques in C. elegans, as well as taking advantage of established methods.