The adrenal glands play a key role in maintaining the physiological balance of birds and
helping them to survive environmental changes. The objective of the present work was to
give a detailed investigation of the histological, ultrastructural, and immunohistochemical
findings of the adrenal gland in Japanese quail during the prehatching phase. The current
study was performed on 45 healthy Japanese quail embryos at different prehatching
periods. Our results showed the primordium of the quail's adrenocortical tissue appeared
at 3 days of incubation as a thickening of the splanchnic mesoderm. The prospective chromaffin cells appeared at 5 days as clusters of cells migrated from the neural crest cells
along the dorsal aorta toward the interrenal tissue. TH immunoreactivity was observed in
the neural crest cells during their migration toward the adrenal primordium. Furthermore,
these TH immunopositive cells were intermingled with the developing interrenal cell cords
that developed from the coelomic epithelium. NSE immunostaining was detected within
the cytoplasm of interrenal cells, chromaffin cells, and ganglion cells. Sox10 is expressed in
chromaffin and ganglion cells with different staining intensities. On the 13th day of prehatching, both interrenal and chromaffin cells were β-catenin immunonegative, but on the
17th day, both cells were immunopositively. Our findings show that during prenatal life,
the adrenal gland undergoes significant morphological changes. Together, the present data
suggest that studying the prenatal development of the adrenal gland in birds is important
for advancing our understanding of this critical organ and its functions.
 

https://analyticalsciencejournals.onlinelibrary.wiley.com/journal/10970029