Meeting Abstract

P2-71  Monday, Jan. 5 15:30  Effects of season and incubation temperature fluctuation frequency on oxidative stress in hatchling red-eared sliders (Trachemys scripta) TREIDEL, LA*; BOWDEN, RM; Illinois St. Univ.; Illinois St. Univ. latreid@ilstu.edu

Maternally derived yolk antioxidants promote cell differentiation and immune function, while protecting offspring from oxidative stress during embryonic and early postnatal periods in oviparous species. The role of yolk antioxidants in reptiles is presently unknown, but given their life-history, antioxidants may play crucial and unique roles in reptilian development. We performed two experiments to independently determine how season and temperature fluctuation frequency during incubation impact oxidative stress in the red eared slider turtle (Trachemys scripta). To investigate seasonal effects of egg production on oxidative stress, clutches collected either early or late in the 2013 nesting season were randomly and evenly assigned to a constant temperature (29.5°C) or daily sinusoidal fluctuating temperature incubation (28.7+3°C) treatment, which has a constant temperature equivalent of 29.4°C. To assess the effect of temperature fluctuation frequency on oxidative stress, eggs from early season clutches were incubated in one of three fluctuating incubation regimes; 28.7+3°C sinusoidal fluctuations every 12 (Hyper), 24 (Normal), or 48 hours (Hypo). After hatching all individuals from both experiments were sacrificed and liver and brain tissues were harvested. Lipid peroxidation and total antioxidant capacity (TAC) of tissues were then spectrophotometrically determined. We report that regardless of season and incubation conditions, both lipid peroxidation and TAC were significantly related to clutch identity. Furthermore, while antioxidant systems appear to sufficiently protect individuals from oxidative damage during embryonic development, TAC was negatively affected by season and low frequency (Hypo) temperature fluctuations.