Metabolomics reveal physiological changes in mayfly larvae (Neocloeon triangulifer) at ecological upper thermal limits

Abstract

Aquatic insects play critical roles in freshwater ecosystems and temperature is a fundamental driver of species performance and distributions. However, the physiological mechanisms that determine the thermal performance of species remain unclear. Here we used a metabolomics approach to gain insights into physiological changes associated with a short-term, sublethal thermal challenge in the mayfly Neocloeon triangulifer (Ephemeroptera: Baetidae). Larvae were subjected to a thermal ramp (from 22 to 30 °C at a rate of 1°C/h) and metabolomics analysis (both Nuclear Magnetic Resonance (NMR) Spectroscopy and Gas Chromatography coupled Time-of-Flight Mass Spectrometry (GC-TOF-MS)) indicated that processes related to energetics (sugar metabolism) and membrane stabilization primarily differentiated heat treated larvae from controls. Limited evidence of anaerobic metabolism was observed in the heat treated larvae at 30°C, a temperature that is chronically lethal to larvae.

Antibiotic-induced acceleration of type 1 diabetes alters maturation of innate intestinal immunity

“…Rxi5Sil-MS column with 0.25 µm film thickness (Restek, Bellefonte PA), using a 250°C injector temperature in splitless mode with 25 s splitless time, at a constant flow of 1 ml/min. The oven temperature was ramped (20°C/min ramp) from 50°C to 330°C ( Chou et al, 2017 ). Data were acquired using a Leco Pegasus 4D TOF-MS (Leco, Saint Joseph MI) with a 280°C transfer line temperature, electron ionization at –70 V, and an ion source temperature of 250°C.…”

EDC IMPACT: Molecular effects of developmental FM 550 exposure in Wistar rat placenta and fetal forebrain

“…Samples were derivatized using a two-step method with acquisition parameters similar to methods described in detail ( 61 , 62 , 63 ). To summarize (as described previously ( 63 )), a 0.5 µL volume was injected into an Agilent 6890 gas chromatograph (Santa Clara, CA, USA) with a 30 m long, 0.25 mm i.d. Rxi5Sil-MS column with 0.25 µm film thickness (Restek, Bellefonte PA, USA), using a 250°C injector temperature in splitless mode with 25 s splitless time, at a constant flow of 1 mL/min.…”

The Good, the Bad, and the Lethal: Gene Expression and Metabolomics Reveal Physiological Mechanisms Underlying Chronic Thermal Effects in Mayfly Larvae (Neocloeon triangulifer)

“…Although the effect of histamine on feeding behavior and growth/development in insects has not been studied, it is possible that thermally driven increases in histamine reduces food intake in mayfly larvae, resulting in smaller body size and associated reduction in fecundity (Figure 4). Interestingly, histamine was not identified in the short term thermally challenged N. triangulifer larvae (Chou et al, 2017). This suggests there may be an association between histamine and growth/development.…”

“…was the first to apply these techniques on critical maximal temperatures (CT max ) acute thermal ramping challenges. Chou et al (2017) conducted an exploratory study on metabolic changes under acute thermal ramping challenges in N. triangulifer. Temperatures chosen for that study were based on chronic thermal limits, but the exposure was a single 8 h, 8 • C thermal ramp.…”