Molecular mechanisms underlying avian metabolic variation: a genomic approach

metabolic gene expression;coding mutation;Dark-eyed Junco;Tachycineta;pace of life

Stager, Maria ; Cheviron ; Zachary A.

关键词: metabolic gene expression;    coding mutation;    Dark-eyed Junco;    Tachycineta;    pace of life;   

Others  :  https://www.ideals.illinois.edu/bitstream/handle/2142/50552/Maria_Stager.pdf?sequence=1&isAllowed=y

美国|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

Physiological adaptive acclimatization allows an organism to balance the competing demands of its life cycle and environment. This thesis seeks to further our understanding of the processes underlying physiological acclimation by characterizing two molecular mechanisms that enable organisms to mount physiological responses to changing environmental conditions. Comprised of two investigations, it focuses on the molecular mechanisms underlying variation in avian aerobic performance. In the first, I explore regulatory changes that act on relatively short time periods, enabling organisms to respond to rapid environmental changes within an individual’s lifetime. I show that thermogenic flexibility manifested from simultaneous changes in the expression of genes within hierarchical regulatory networks in response to temperature in the Dark-eyed Junco (Junco hyemalis). This transcriptomic variation resulted in rapid physiological modifications within individuals. In the second, I instead characterize coding mutations that occur on the timescale of generations. I show that differences in the mitochondrial sequences of the genes encoding the machinery of cellular metabolism could result in canalized differences in whole-organism aerobic performance among Tachycineta swallow species. Sites of positive selection were concentrated in species with ‘slow’ life histories that may be associated with low metabolic rates. Together these investigations provide a concise survey of the molecular tools birds are equipped with to metabolically respond and adapt to environmental variation.