الفهرس 
ACKNOWLEDGEMENTSOnly 14 pages are availabe for public view
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Abstract
The present study was investigated the developmental stages of the adrenal gland of the Japanese quail. It was carried out on 45 embryos and 35 quail’s chicks. The materials were collected from the Research Farm of Faculty of Agriculture, Assiut University. The specimens of the adrenal gland were fixed in the proper fixatives and prossesed for histological, histochemical and immunohistochemical investigation. Paraffin sections of some ages were used for scanning and transmission electron examination. The main results that were observed during this study could be summarized as follow:
The interrenal primordium of the adrenal gland of Japanese quail was observed on the 3rd embryonic day (ED) as a thickening of the coelomic epithelium and this thickning was protruded into the coelomic cavity as a fold.
On the 4th ED, the interrenal cells that form this fold were proliferated and increased in size.
On the 5th ED, the cells of the interrenal tissue migrated dorsally and reach their position on either side of the dorsal aorta and medial to the mesonephros. At this stage of development, these cells were characterized by their high nucleocytoplasmic ratio.
Also, at this stage of development, the primordium of the chromaffin tissue appeared as row of migrating neural crest cell.
The migrating neural crest cells showed strong positive reaction for TH during their way of migration and this indicate that their
differentiation into chromaffin cells occurred before reaching the interrenal tissue of the adrenal gland.
from this stage of development, the adrenal gland became surrounded by thin mesenchymal layer that form the capsule of the adrenal gland and this layer contained different mesenchymal cells as telocytes and fibroblasts.
On the 7th ED, the adrenal gland was formed of intermingled interrenal and chromaffin tissues and this gland reach its adult position from this stage of development, dorsolteral to the dorsal aorta and medial to the mesonephros.
On the 11th ED, the cells of the interrenal tissue started their arrangement into rows of two cell lines and they were columnar with apically located nuclei.
On the 15th ED, the adrenal parenchyma started its arrangement of three different zones; subcapsular, peripheral and central zones and the narrowest zone was the subcapsular one.
During the pre- hatching period, the cells of the interrenal tissue contained moderate amount of lysosomes and mitochondria. The amount of mitochondria greately increased during the post- hatching period.
Small granule containing cells (SGC) appeared during pre- and post- hatching periods peripheral to the chromaffin cells.
The chromaffin cells during the pre- hatching period were’t differentiated into epinephrine and norepinephrine producing cells and this differentiation started from 17th ED.
The lipid and mitochondrial content within the cells of the interrenal tissue was higher at the central zone than the peripheral one.
The chromaffin cells showed positive reaction for NSE protein. The cells of the interrenal tissue showed a less staining level for NSE protein than the chromaffin cells but this level increased with increasing age.
The chromaffin cells showed positive Sox10 reaction that increased with age while the cells of the interrenal tissue were negative for sox 10 protein.
β-catenin was expressed within the plasmalemma and the cytoplasm of the cells of the interrenal tissue and chromaffin cells.
The chromaffin cells at central zone showed stronger reaction for chromogranin A than that at the peripheral one, and this reaction was confined to the cell junctions only while the cells of the interrenal tissue were negative for chromogranin A.