Effects of temperature on growth and fatty acid synthesis in the cyclopoid copepod Paracyclopina nana

Abstract

We have used the cyclopoid copepod Paracyclopina nana to understand responses to the temperature shift. To determine the changes of molecular mechanisms, which would lead to physiological changes in P. nana, we investigated mRNA expression involved in lipogenesis, the area of lipid droplets, the ratio of fatty acids, and life parameters (growth and fecundity) in response to temperature changes (15, 20, and 30 A degrees C) with comparative control at 25 A degrees C. Setting the temperature 25 A degrees C as a standard point, there were increases in mRNA expression, the area of the lipid droplets, and fatty acid composition at temperatures below the standard (15 A degrees C), while all the markers mentioned above significantly decreased at higher temperatures than the standard (25 A degrees C). Through fecundity and growth rate experiments, daily nauplii production was reduced and growth retardation was observed at both 15 and 20 A degrees C, but no noticeable differences in the two parameters were observed at 30 A degrees C compared to the control (25 A degrees C). This study provides a better understanding of the effects of temperature on lipogenesis in copepods.