Variations in mitochondrial DNA and gene transcription in freezing-tolerant larvae of Eurosta solidaginis (Diptera : Tephritidae) and Gynaephora groenlandica (Lepidoptera : Lymantriidae)

摘要

Respiration, mitochondrial (mt)DNA content, and mitochondrial-specific RNA expression in fat body cells from active and cold-adapted larvae of the goldenrod gall fly, Eurosta solidaginis , and the Arctic woolly bear caterpillar, Gynaephora groenlandica , were compared. Reduced amounts of mtDNA were observed in cold-adapted larvae of both E. solidaginis and G. groenlandica collected in fall or winter, compared with summer-collected larvae. mtDNA increased to levels similar to those of summer-collected larvae after incubation at 10degreesC or 15degreesC for 5 h. Mitochondrial-specific RNAs (COI and 16S) were observed in fat body cells of both active and cold-adapted E. solidaginis larvae. Our results suggest that mitochondrial proteins required for respiration may be restored rapidly from stable RNAs present in overwintering larvae.