A method for partial decapitation of chicken embryos; its limitations as a substitute for adenohypophysectomy - an evaluation of "equivalent" methods in amniotes.

Abstract

ABSTRACT A procedure for partial decapitation, some apparent and possible sources of variation, implications, limitations and validation of the operation as "adenohypophysectomy" are described and considered. Usually 75% of "fertilized" eggs contain embryos eligible for surgery at ~38 hours of incubation and often 90 % of these can be operated upon successfully. The procedure requires 1.5 to 2 minutes per embryo. Mortality is high, but enough partially decapitated embryos can be obtained for quantitative studies even to the onset of hatching. Other apparently less accurate, precise, efficient and/or simple ways to remove adenohypophyseal influence during development in amniote embryos include: electro-cautery or -coagulation, X-rays, laser beams, inhibitors, anti-sera and decapitation. Surgical partial decapitation is a practical device for adenohypophyseal developmental endocrinology of chicken embryos.