Meeting Abstract
Temporal organization is an important aspect of organismal biology, yet little is known about the nature of this variation within populations. We examined temporal variation in hemolymph characteristics in a cricket species with genetically-based differences in circadian fluctuation of juvenile hormone(JH). Circadian fluctuation in JH is thought to regulate the temporal aspects of reproduction and locomotor behavior in insects. If the circadian fluctuation in JH regulates metabolic processes, we would expect to observe correlated changes in hemolymph metabolites. Specifically, morphs with differing JH chronotypes will exhibit hemolymph profiles reflective of their life history patterns. We measured total hemolymph macronutrient content and concentration across the circadian cycle at five time points in five day old female Gryllus firmus.Hemolymph content was quantified using standard biochemical assays, while volume was determined by injection and recovery of a FITC-inulin solution. Overall, the flight capable morph (FC) maintained constitutively lower hemolymph volumes. The FC morph also had higher total lipid content and concentration, which increased toward the evening. There were no significant differences in carbohydrate and protein concentration between morphs, nor did concentrations fluctuate. However, the flightless reproductive morph had higher total protein and carbohydrate amounts. This supports the claim that the JH titer acts as a priming signal for lipid mobilization in FC morphs. Therefore temporal organization of hemolymph volume and content support the physiological and metabolic demands associated with life history patterns like flight preparation.
