Mitochondrial energy utilization maintains young status in the trophocytes and oenocytes of old queen honeybees

The lifespans of queen honeybees (Apis mellifera) are much longer than those of worker bees. Mitochondrial energy utilization in the trophocytes and oenocytes of worker bees during aging has been determined, but it remains unknown in queen bees. In this study, mitochondrial energy utilization was assayed in the trophocytes and oenocytes of young and old queen bees. The mitochondrial density and mitochondrial membrane potential (∆ψm); nicotinamide adenine dinucleotide (NAD⁺), nicotinamide adenine dinucleotide reduced form (NADH), and adenosine triphosphate (ATP) levels; NAD⁺/NADH ratio; and relative expression of NADH dehydrogenase 1 (ND1) and ATP synthase normalized against mitochondrial density were not significantly different between young and old queen bees. These results indicate that mitochondrial energy utilization maintains a young status in the trophocytes and oenocytes of old queen bees and that trophocytes and oenocytes have longevity-promoting mechanisms that can be investigated to clarify the secret of longevity in queen bees.