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1000
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Abstract/Summary
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Phase 1 of the project therefore used CCRT to explore the genetic basis of cold adaptation. First, we identified candidate genes involved in the physiological response to cold shock by comparing gene expression in cold-tolerant and cold-sensitive lines. Second, we could map three quantitative trait loci (QTL) that together explained a substantial 64% of the variation in CCRT in the ancestral population. Last, molecular genome editing tools based on CRISPR/ Cas9 and PiggyBac systems, were established for the first time in D. ananassae to enable future functional studies of candidate genes, not only for cold stress tolerance. Phase 2 extended this work, motivated by debate about whether CCRT alone fully captures ecologically relevant cold tolerance. Further, experiments included cold acclimation and additional phenotypes. The key findings were that cold acclimation improves cold tolerance and dramatically alters gene expression, particularly in ionoregulatory tissues. Importantly, additional cold tolerance phenotypes, such as lethal time and cold shock mortality, were found not to correlate significantly with chill coma recovery time. This highlights that while CCRT is useful, studying multiple phenotypes provides a more complete understanding of cold tolerance. Further genomic analysis linked specific regions influencing CCRT to biological processes like muscle development and metabolism. Overall, this project advanced our knowledge of thermal adaptation in natural populations.
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