Biochemical mechanisms for starvation-hardiness in the soft tick, Ornithodoros turicata Duges (Acari:Argasidae).

摘要

Biochemical mechanisms for starvation-hardiness were investigated in fed and starved nymphal and adult Ornithodoros turicata ticks. Total lipids, carbohydrates and fatty acids were measured to identify energy reserves. Surface lipids were analyzed to detect adaptive mechanisms for preventing desiccation. Dehydrogenase enzymes were detected in tick whole-body sections to compare metabolic pathways of fed and starved ticks. Total lipids increased proportionally in starved nymphs but not in fed nymphs. Total carbohydrates increased proportionally in starved ticks compared to their fed counterparts. A long-chain polyunsaturated fatty acid increased in relative abundance in starved ticks. Two nonpolar surface lipid classes, hydrocarbons and waxes, were detected in starved ticks but not in fed ticks. Lactate and alcohol dehydrogenases were present in starved male ticks only. The ability to store energy in the form of carbohydrates and lipids, alter fatty acid metabolism, prevent desiccation by adding epicuticular lipids and alter energy-releasing metabolic pathways allows O. turicata to cope with starvation.