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Full-Text Articles in Life Sciences

Severe Hypoxia Up-Regulates Gluconeogenesis In Daphnia, Morad C. Malek May 2022

Severe Hypoxia Up-Regulates Gluconeogenesis In Daphnia, Morad C. Malek

Undergraduate Honors Theses

Hypoxia is a significant low oxygen state that has complex and diverse impacts on organisms. In aerobes, various adaptive responses to hypoxia are observed that vary depending on the level of oxygen depletion and previous adaptation, hence the continued attention to hypoxia as an important abiotic stressor. Adaptive responses to hypoxia are primarily governed by the hypoxia-inducible factors (HIFs), which activate downstream genetic pathways responsible for oxygen transport and metabolic plasticity. In aquatic habitats, oxygen availability can vary greatly over time and space. Therefore, aquatic organisms’ adaptation to hypoxia is likely pervasive, especially in genotypes originating from waterbodies prone to …


Effects Of Maternal And Neonatal Hypoxia On The Future Life History Of Daphnia Magna, Rachael Lowman Dec 2021

Effects Of Maternal And Neonatal Hypoxia On The Future Life History Of Daphnia Magna, Rachael Lowman

Undergraduate Honors Theses

Early exposure to hypoxia is related to a variety of physiological and metabolic changes that have lasting effects on organisms’ physiology and life history. We measured the effects of maternal and embryonic mild, intermittent hypoxia on the life history of four clones of microcrustacean Daphnia magna, an emerging model organism for the studies of senescence and longevity. Daphnia individuals were produced parthenogenically, maintained in individual vials, and fed standard algal concentration daily. The cohort consisted of 189 individuals. We measured body size at first reproduction, fecundity (including late-life fecundity peak), offspring sex ratio, and longevity. We found no effect …


Effects Of Respiratory Perturbations On Aging And Healthspan In Daphnia Magna, Millicent Nkiruka Ekwudo May 2021

Effects Of Respiratory Perturbations On Aging And Healthspan In Daphnia Magna, Millicent Nkiruka Ekwudo

Electronic Theses and Dissertations

Aging is a degenerative process characterized by a decline in physiological functions and cellular activities. Environmental and pharmacological interventions affecting longevity pathways have been extensively studied in model organisms. This study investigated the effect of chronic mild intermittent hypoxia (4 mg O2/L) or mild mitochondrial uncoupling with three doses of 0 (control), 0.1, 1, and 5 μM of 2,4-Dinitrophenol (DNP), on life history and gene expression in four clones of Daphnia magna. Interestingly, clones from intermittent ponds displayed better tolerance to hypoxia and DNP. Although neither treatments extended longevity, hypoxia increased fecundity and body size, and decreased food consumption and …