Effect of exogenous corticosterone on chicken embryonic development

Area of Science:

• Developmental Biology
• Endocrinology
• Avian Embryology

Background:

• Corticosterone (CS) is a key hormone regulating stress and development in vertebrates.
• The role of embryonic corticosterone in avian development and hatching success is not fully understood.
• Understanding embryonic hormone levels is crucial for assessing developmental health and potential interventions.

Purpose of the Study:

• To investigate the effects of exogenous embryonic corticosterone exposure on Leghorn egg development.
• To determine the dose-dependent impact of corticosterone on embryonic mortality, growth, and serum CS levels.
• To elucidate the critical role of embryonic corticosterone in normal avian embryonic development and hatchability.

Main Methods:

• Fertile Leghorn eggs were dipped in varying concentrations (0, 0.01, 0.05, 1%) of corticosterone in ethanol.
• Embryonic mortality was assessed daily via candling from Day 4 through hatch.
• Embryo body weights and serum corticosterone levels were measured daily from Day 14 until hatch.

Main Results:

• Exposure to 1% corticosterone significantly reduced circulating embryonic CS levels.
• Increasing corticosterone concentrations correlated with reduced embryo weights and increased mortality rates.
• A pre-hatch CS peak was observed in control and lower concentration groups, but absent in the 1% group; all 1% embryos died before hatching.

Conclusions:

• Exogenous corticosterone exposure significantly disrupts normal avian embryonic development.
• Embryonic corticosterone plays a vital role in regulating growth, survival, and the hatching process.
• The study highlights the sensitivity of embryonic development to hormonal fluctuations and the importance of endogenous CS regulation.