Compensatory growth in C. elegans is regulated by a thermosensitive TRP channel and increases reproductive fitness

We set to measure compensatory growth and slowed-down plasticity, and its consequences for age-specific reproduction and lifespan in wild-type <i>Caenorhabditis elegans</i> worms as well as worms with a null-mutation in the <i>trpa-1</i> gene. Newly laid eggs of worms were exposed to one of three temperatures: 15°C, 20°C or 25°C until they reached third larval stage whereafter we moved them to standard temperature (20°C). To asses growth rate we photographed worms every 24h for five consecutive days (since switch to 20°C). We analyzed the photographs using ImageJ to calculate the total area of the worms and we calculated growth rate as the size of a worm each day, divided by the number of days since the switch to 20°C. We checked worms every 24h to assess lifespan and if still alive, we moved them to a new plate. We kept the old plates to allow eggs to hatch, and after 48h we counted offspring to asses a daily fecundity.