Lung respiration, somatic activity and gas metabolism in embryonic chicks prevented from hatching by thiourea

Area of Science:

• Embryology
• Developmental Biology
• Physiology

Background:

• Avian hatching is a complex process involving physiological and behavioral changes.
• The role of active breathing in initiating hatching remains incompletely understood.

Purpose of the Study:

• To investigate the effect of thiourea on chick embryo hatching and related physiological parameters.
• To determine the importance of active breathing in the prenatal period for successful hatching.

Main Methods:

• Chick embryos were treated with high doses of thiourea (32.8 mumol) on day 17 of incubation.
• Key parameters monitored included hatching success, active breathing, oxygen consumption, and somatic activity.

Main Results:

• Thiourea treatment prevented hatching and active breathing in chick embryos.
• The drug also inhibited the expected increase in oxygen consumption and somatic activity prior to hatching.
• These results indicate a direct link between active breathing and the hatching process.

Conclusions:

• Active breathing in the prenatal period is essential for initiating pipping and hatching in avian embryos.
• Thiourea's inhibitory effects underscore the physiological importance of prenatal respiration for embryonic development and emergence.