Post-hatching developmental changes in the adrenal gland of the Japanese quail (Coturnix coturnix japonica): Histological, immunohistochemical, and electron microscopic studies

Dynamics of the Posthatching Testicular Development in Japanese Quail (Coturnix coturnix japonica): Histological and Ultrastructural Study

The posthatching development of the testis is a well-organized process comprising the maturation of Sertoli cells, the development of Leydig cells, and the differentiation of germ cells. This study aimed to investigate the posthatching testicular development in the Japanese quail, using light and electron microscope. The current study was performed on 25 healthy Japanese quail chicks at 0, 7, 21, 40, and 50 posthatching days. The results revealed that the testis consists of solid seminiferous cords, and their lining epithelium is composed of two types of cells; immature Sertoli cells and gonocyte or spermatogonia at the early stage, which begins from the day of hatching till 21 days posthatching. The interstitium during this period consisted of different developmental stages of the Leydig cells. However, at the late posthatching developmental stage the testis is characterized by the presence of round and elongated spermatids as well as the initiation of spermiogenesis. The interstitial compartment also showed an increase in the number and size of Leydig cells. The findings of the current study provide comprehensive insights into the posthatching development of the Japanese quail testis, contributing to the understanding of avian reproduction.

Post-hatch Development of the Adrenal Gland in Chickens (Gallus gallus domesticus): Insights From Histology, Immunohistochemistry, Transmission Electron Microscopy, and Catecholamine Level Analysis

This study is the first to describe posthatching morphological changes in chicken adrenal glands using histology, immunohistochemistry, transmission electron microscopy, and catecholamine levels. The study involved 30 chickens in 3 posthatching stages: Juvenile (1 day old), immature (2 months old), and mature (6 months old). The results showed no demarcation between cortical and medullary, with the interrenal tissue comprising most of the adrenal parenchyma. The 1-day-old chickens did not exhibit the zoning of interrenal tissue into subcapsular and inner zones, while as they aged, the proportion of medullary tissue increased. The norepinephrine-secreting cells exhibited a significantly higher number of secretory granules compared to the epinephrine-secreting cells across the different stages. The plasma levels of catecholamines increased with advancing age. Chromogranin immunoactivity increased with age during the development of the adrenal gland. It can be concluded that the adrenal gland undergoes significant structural and functional changes during various posthatching developmental periods. In general, the study provides valuable insights into the growth and maturation of the adrenal glands in posthatch chickens, potentially aiding in understanding their maturation and their role in controlling catecholamines. In conclusion, the findings suggest that optimizing stress responses in chickens could enhance poultry production, potentially leading to the development of new stress management strategies.

Prehatching development of the adrenal gland in Japanese quail (Coturnix japonica): Histological, immunohistochemical, and electron microscopic studies

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. RESEARCH HIGHLIGHTS: The present study aimed to give a detailed study of the histological, ultrastructural, and immunohistochemical investigations of the adrenal gland in Japanese quail during the prehatching period. The interrenal primordium was observed on the third embryonic day, on the fifth ED the primordium of the chromaffin tissue appeared as row of migrating neural crest cell. At the ultrastructural level, the interrenal cells take steroid-secreting cells characters, they have varying amounts of lipid droplets and abundant mitochondria at 15th ED contained moderate number of lysosomes and mitochondria.

Morphological and Immunohistochemical Differentiation of Neuronal and Glial Cells of the Vascular and Avascular Regions of the Donkey's Paurangiotic Retina

INTRODUCTION

Ocular diseases pose a significant health concern for donkeys. However, studies examining the microanatomy and cell populations of the donkey retina are scarce. The current study aimed to describe the vascular pattern of the donkey retina and document its cellular components.

METHODS

The donkey retina specimens were obtained from different retinal regions and prepared for semithin sectioning and immunohistochemistry.

RESULTS

The donkey has a paurangiotic retina in which retinal vessels are confined to a narrow area around the optic disc. Glial cells coexist with the blood vessels being very numerous in the vascular region and become scanty in the avascular ones. S-100-positive astrocytes could be observed in these avascular areas. Ganglion cells are organized in a single layer with the least population existing in the peripheral retina. Acidic fibroblast growth factor (AFGF) is immunoreactive in amacrine and ganglion cells. A subpopulation of amacrine cells reacted strongly to tyrosine hydroxylase (TH), and others reacted positively to S-100 protein. Ganglion cell nuclei exhibited a strong immunoreactivity to S-100 protein as well. Furthermore, glial fibrillary acidic protein (GFAP) is used to identify Müller cells that extend their processes across the retina from the inner to the outer limiting membrane.

CONCLUSIONS

In conclusion, our findings provide novel insights into the normal retinal organization. The donkey retina shows the characteristic expression of immunohistochemical markers for the major cell types. In addition, the distribution of glial cells is comparable between the vascular and avascular regions.

Meckel's Diverticulum in Adult Geese (Alopochen egyptiacus): A Comprehensive Study of Structure Using Histological, Electron Microscopy, and Immunohistochemical Methods

INTRODUCTION

The intestine plays an important role in mediating between the bird and its nutritional environment. The yolk stalk, also known as Meckel's diverticulum, is a landmark between the jejunum and ileum. This work aimed to investigate the anatomical, histological, and electron microscopical features of cellular components of the Meckel's diverticulum (MD) in adult geese.

METHODS

The intestine was dissected from the bird's body cavity, and Meckel's diverticulum was exposed and prepared for light and electron microscopical examinations.

RESULTS

Our results revealed that the MD mucosa is thrown up into villi and crypts, and the mucosal epithelium is a columnar epithelium with goblet cells as well as intraepithelial lymphocytes. Lymphoid follicles and numerous immune cells were demonstrated within the lamina propria. The mucous glands were also observed within the lamina propria and among the lymphoid follicles. The lining epithelium of MD appeared with different staining affinities: dark cells (electron-dense) and light cells (electron-lucent) contained few mitochondria and more secretory vesicles, while dark cells contained more mitochondria and fewer secretory vesicles. Immunohistochemical analysis of MD revealed positive immunoreactivity for several markers, such as CD117, chromogranin, PLCβ, cytokeratin, MHC II, and S100.

CONCLUSION

Taken together, our findings suggest that MD is considered an immune organ in adult geese.