Tissue-Specific Transcriptomic Reprogramming in the Brain and Ovary of Mated Bombus terrestris Queens During Overwintering
This study compared the brain and ovary of mated Bombus terrestris queens after 4 and 12 weeks of overwintering to identify tissue-specific molecular changes. The results showed that, at 12 weeks, the brain was characterized mainly by enrichment of RNA processing and protein synthesis-related functions, such as the spliceosome and ribosome. In the ovary, 12 weeks of overwintering was associated with strong activation of translation-related functions and cellular structural reorganization, including ribosome, spindle, and microtubule-related processes. In contrast, the ovary at 4 weeks showed higher expression of genes related to fatty acid metabolism and biosynthesis, suggesting a state closer to storage metabolism. Overall, the findings indicate that prolonged overwintering induces distinct but connected transcriptomic changes, with the brain showing RNA-processing-centered regulation and the ovary shifting from storage metabolism toward preparation for reproductive reactivation.