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Full-Text Articles in Life Sciences
Long-Term Survival Of Anoxia Despite Rapid Atp Decline In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Jason E. Podrabsky, Michael A. Menze, Steven C. Hand
Long-Term Survival Of Anoxia Despite Rapid Atp Decline In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Jason E. Podrabsky, Michael A. Menze, Steven C. Hand
Faculty Research & Creative Activity
Embryos of the annual killifish Austrofundulus limnaeus can survive for months in the complete absence of oxygen. Survival of anoxia is associated with entry into a state of metabolic dormancy known as diapause. However, extreme tolerance of anoxia is retained for several days of post-diapause development. Rates of heat dissipation in diapause II and 4 days post-diapause II embryos were measured under aerobic conditions and during the transition into anoxia. Phosphorylated adenylate compounds were quantified in embryos during entry into anoxia and after 12 hr of aerobic recovery. Rates of heat dissipation were not affected by exposure to anoxia in …
Metabolic Restructuring During Energy-Limited States: Insights From Artemia Franciscana Embryos And Other Animals, Steven C. Hand, Michael A. Menze, Apu Borcar, Yuvraj Patil, Joseph A. Covi, Julie A. Reynolds, Mehmet Toner
Metabolic Restructuring During Energy-Limited States: Insights From Artemia Franciscana Embryos And Other Animals, Steven C. Hand, Michael A. Menze, Apu Borcar, Yuvraj Patil, Joseph A. Covi, Julie A. Reynolds, Mehmet Toner
Faculty Research & Creative Activity
Many life history stages of animals that experience environmental insults enter developmental arrested states that are characterized by reduced cellular proliferation, with or without a concurrent reduction in overall metabolism. In the case of the most profound metabolic arrest reported in invertebrates, i.e., anaerobic quiescence in Artemia franciscana embryos, acidification of the intracellular milieu is a major factor governing catabolic and anabolic downregulation. Release of ion gradients from intracellular compartments is the source for approximately 50% of the proton equivalents needed for the 1.5 unit acidification that is observed. Recovery from the metabolic arrest requires re-sequestration of the protons with …
Mechanisms Of Apoptosis In Crustacea: What Conditions Induce Versus Suppress Cell Death?, Michael A. Menze, Grady Fortner, Suman Nag, Steven C. Hand
Mechanisms Of Apoptosis In Crustacea: What Conditions Induce Versus Suppress Cell Death?, Michael A. Menze, Grady Fortner, Suman Nag, Steven C. Hand
Faculty Research & Creative Activity
Arthropoda is the largest of all animal phyla and includes about 90% of extant species. Our knowledge about regulation of apoptosis in this phylum is largely based on findings for the fruit fly Drosophila melanogaster. Recent work with crustaceans shows that apoptotic proteins, and presumably mechanisms of cell death regulation, are more diverse in arthropods than appreciated based solely on the excellent work with fruit flies. Crustacean homologs exist for many major proteins in the apoptotic networks of mammals and D. melanogaster, but integration of these proteins into the physiology and pathophysiology of crustaceans is far from complete. Whether apoptosis …
Mitochondria In Energy-Limited States: Mechanisms That Blunt The Signaling Of Cell Death, Steven C. Hand, Michael A. Menze
Mitochondria In Energy-Limited States: Mechanisms That Blunt The Signaling Of Cell Death, Steven C. Hand, Michael A. Menze
Faculty Research & Creative Activity
Cellular conditions experienced during energy-limited states – elevated calcium, shifts in cellular adenylate status, compromised mitochondrial membrane potential – are precisely those that trigger, at least in mammals, the mitochondrion to initiate opening of the permeability transition pore, to assemble additional protein release channels, and to release pro-apoptotic factors. These proapototic factors in turn activate initiator and executer caspases. How is activation of mitochondria-based pathways for the signaling of apoptotic and necrotic cell death avoided under conditions of hypoxia, anoxia, diapause, estivation and anhydrobiosis? Functional trade-offs in environmental tolerance may have occurred in parallel with the evolution of diversified pathways …