Meeting Abstract
Developmental stressors are thought to have a negative impact on physiological functions and fitness. However, recent work suggests that a mild developmental stressor can have beneficial effects by increasing tolerance to the stressor later in life. The environment experienced by the parental generation can also affect offspring phenotype prior to fertilization or through parental effects. Adaptive transgenerational plasticity has been well documented in invertebrates, however less is known in the vertebrate taxa. We hypothesized that acquired stress tolerance decreases the negative effects of heat stress on fitness-related traits, and that this effect carries on into the next generation. To test this we conditioned juvenile zebra finches (Taeniopygia guttata) to a mild heat stress (38° C) or control temperature for 28 days. Later after reaching adulthood, the female birds were then exposed to a high heat stress (42° C) or control temperature for 3 consecutive days and then paired. The eggs of those females were then collected and incubated at a control or high temperature, and embryonic heart rates were measured at two time points [embryonic day 4 & 10/11] during development. Hatchlings were later euthanized to quantify organ mass. We predict that embryos from heat conditioned, heat stressed mothers will have heart rates in the high heat incubator comparable to embryos from control-control mothers that were in the control incubator. We also predict that hatchlings from heat conditioned, heat stressed mothers in the high heat incubator will have heart, yolk, and body masses comparable to hatchlings from control-control mothers in the control incubator. We will discuss the results in relation to developmental plasticity and potential mechanisms.
