The Transcription of Flight Energy Metabolism Enzymes Declined with Aging While Enzyme Activity Increased in the Long-Distance Migratory Moth, Spodoptera frugiperda

Abstract

Of all the things that can fly, the flight mechanisms of insects are possibly the least understood. By using RNAseq, we studied the aging-associated gene expression changes in the thorax of Spodoptera frugiperda females. Three possible flight energy metabolism pathways were constructed based on 32 key metabolic enzymes found in S. frugiperda. Differential expression analysis revealed up to 2000 DEGs within old females versus young ones. Expression and GO and KEGG enrichment analyses indicated that most genes and pathways related to energy metabolism and other biological processes, such as transport, redox, longevity and signaling pathway, were downregulated with aging. However, activity assay showed that the activities of all the five tested key enzymes increased with age. The age-associated transcriptional decrease and activity increase in these enzymes suggest that these enzymes are stable. S. frugiperda is a long-distance migrator, and a high activity of enzymes may be important to guarantee a high flight capacity. The activity ratio of GAPDH/HOAD ranged from 0.594 to 0.412, suggesting that lipid is the main fuel of this species, particularly in old individuals. Moreover, the expression of enzymes in the proline oxidation pathway increased with age, suggesting that this energy metabolic pathway also is important for this species or linked to some aging-specific processes. In addition, the expression of immunity- and repair-related genes also increased with age. This study established the overall transcriptome framework of the flight muscle and aging-associated expression change trajectories in an insect for the first time.

Molecular Characterization and Phylogenetic Analysis of Flightin Gene in Vespa basalis (Hymenoptera, Vespidae)

“…Comparing the flightin amino acid sequences of V. basalis with other species, we found 67 conserved sites, 29 completely conserved regions, and 30 conserved replacement sites. In comparison, the flightin proteins of the brown planthopper [ 31 ] and Spodoptera litura [ 32 ] have 14 and 31 completely conserved regions, respectively. The flightin protein sequence shows a relatively conservative nature, with the critical factors involved in muscle regulation primarily located in the middle region.…”