GSE157915
Transcriptomic analysis of the trade-off between endurance and burst-performance in the frog Xenopus allofraseri
Background: Variation in locomotor capacity among animals often reflects adaptations to different environments. Despite evidence that physical performance is heritable, the molecular basis of locomotor performance and performance trade-offs remains poorly understood. In this study we identify the genes, signaling pathways, and regulatory processes responsible for the trade-off between burst performance and endurance observed in Xenopus allofraseri, using a transcriptomic approach. Results: We obtained a total of about 121 million paired-end reads from Illumina RNA sequencing and analyzed 218,541 transcripts obtained from a de novo assembly. We identified 109 transcripts with a significant differential expression between endurant and burst performant individuals (FDR = 0.05 and logFC = 2), and blast searches resulted in 103 protein-coding genes. We found major differences between endurant and burst-performant individuals in the expression of genes involved in the polymerization of actin filaments, cellular trafficking, proteoglycans and extracellular proteins secreted, lipid metabolism, mitochondrial activity and regulators of signaling cascade. Remarkably, we revealed transcripts isoforms of key genes with function in metabolism, apoptosis, nuclear export and as transcriptional corepressor, expressed in either burst-performant or endurant individuals. Lastly, we find two up-regulated transcripts in burst-performant individuals that correspond to the expression of myosin-binding protein C fast-type (mybpc2). This suggests the presence of mybpc2 homoeologs and may have been favored by selection to permit fast and powerful locomotion. Conclusion: Locomotor performance trade-off in Xenopus allofraseri can be attributed to the differential expression of genes belonging to the different pathways of calcium signaling, endoplasmic reticulum stress response and striated muscle contraction, but also attributed to the use of alternative splicing and regulatory processes. Ultimately, our transcriptomic analysis offers new perspectives for future analyses of the role of single nucleotide variants, homoeology and alternative splicing in the evolution of locomotor performance trade-offs. Overall design: Differential expression analysis between four endurant and four burst-performant males