Project description:Many terrestrial ectotherms have gone to great evolutionary lengths to adapt to long cold winters; some have even evolved the ability to tolerate the freezing of most of the water in the body. Now, however, high-elevation, and high-latitude winters are experiencing an accelerated period of warming. Specialized winter adaptations that promoted fitness in a seasonally frozen environment may soon be superfluous or even maladaptive. We ask whether winter adaptations include changes in immune functions, and whether changing winter conditions could exert disparate effects on populations of a wide-ranging terrestrial ectotherm, the wood frog (Lithobates sylvaticus). By rearing wood frogs from ancestral winter environments that vary in length and temperature in a common garden, and reciprocally crossing post-metamorphic frogs into unfrozen and frozen artificial winter conditions in the lab, we were able to decompose transcriptomic differences in ventral skin gene expression into those that were environmentally induced (responsive to temperature), genetically determined, and those that varied as an interaction between genotype and environment. We found that frogs from harsh ancestral winter environments upregulated immune processes, including cellular immunity, inflammatory processes, and adaptive immune processes, as compared to frogs from mild ancestral winter environments. Further, we saw that expression of several genes varied in an interaction between genotype and artificial winter environment, a pattern that was recapitulated at the level of hepatosomatic index (the proportion of body mass comprising liver). We suggest that just as winter climates likely served as the selective force resulting in remarkable winter adaptations such as freeze tolerance, they also induced constitutive changes in immune gene expression.
Project description:Ectothermic animals that live in seasonally cold regions are adapted to seasonal variation and specific environmental conditions. During the winter, some amphibians hibernate terrestrially and encounter a limited amount of environmental water, deficient oxygen, and extremely low temperatures that can cause whole body freezing. These stresses trigger physiological and biochemical adaptations in amphibians that allow them to survive. Rana sylvatica, commonly known as the wood frog, shows excellent freeze tolerance. They can slow their metabolic activity to a near halt and endure freezing of 65-70% of their total body water as extracellular ice during hibernation, returning to normal when the temperatures rise again. To investigate the molecular adaptations of freeze-tolerant wood frogs, a comprehensive proteomic analysis was performed on frog liver tissue after anoxia, dehydration, or freezing exposures using a label-free LC-MS/MS proteomic approach. Quantitative proteomic analysis revealed that 87, 118, and 86 proteins were significantly upregulated in dehydrated, anoxic, and frozen groups, respectively, suggesting potential protective functions. The presence of three upregulated enzymes, glutathione S-transferase (GST), aldolase (ALDOA), and sorbitol dehydrogenase (SORD), were validated. For all enzymes, the specific enzymatic activity was significantly higher in liver of frozen and anoxic groups compared to controls. This study reveals that GST, ALDOA, and SORD might participate in the freeze tolerance mechanism by contributing to regulating cellular detoxification and energy metabolism.
2024-08-10 | PXD050540 | Pride
Project description:Microbial diversity of freezing-thawing soil
| PRJNA682512 | ENA
Project description:Effects of freezing and thawing on microorganisms
Project description:Methanol extractions of GI dissections of laboratory-reared wood frogs that were selectively inoculated with the herptile gut fungus, Basidiobolus.
Project description:Methanol extractions of fecal pellets collected from laboratory-reared wood frogs that were selectively inoculated with the herptile gut fungus, Basidiobolus.
Project description:Methanol extractions of fecal pellets collected from laboratory-reared wood frogs that were selectively inoculated with the herptile gut fungus, Basidiobolus.
2024-08-07 | MSV000095549 | MassIVE
Project description:Metatransciptomics analysis of thawing and freezing active layer permafrost
| PRJNA417839 | ENA
Project description:Effects of freezing and thawing on soil bacterial community