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.

Aquaculture faces significant challenges from bacterial pathogens such as Pseudomonas putida, which causes severe infections in Nile tilapia (Oreochromis niloticus), leading to economic losses and public health concerns. To address this, a bacterial ghost vaccine of P. putida (PPGs) was developed using a sponge-like reduced protocol, ensuring structural integrity and complete inactivation while preserving immunogenic surface components. The vaccine was formulated with a water-in-oil-in-water (W/O/W) adjuvant to enhance immunogenicity. Efficacy of the vaccine were evaluated in tilapia through serum IgM quantification, gene expression analysis, and challenge trials. Results demonstrated that both plain and adjuvanted PPGs vaccines elicited robust humoral and cellular immune responses, with significant upregulation of immune-related genes (IL-1β, IL-8, IgM, MHC-II α) and high serum IgM levels. The adjuvanted PPGs vaccine provided superior protection, achieving relative percent survival (RPS) values of 76.8 %, 93.9 %, and 97.2 % at 4-, 8-, and 10-weeks post-vaccination, respectively, compared to plain PPGs (62.9 %, 67.8 %, 64.4 %). No adverse effects resulted from the PPGs vaccine administration were observed, confirming the vaccine's biocompatibility. These results prove that the adjuvanted PPGs vaccine prepared herein is a safe and effective prophylactic intervention in Nile tilapia aquaculture against P. putida infections, conferring durable immunity and exhibiting potential for scalable implementation.

This study provides a detailed histological and immunohistochemical analysis of the kidney and adrenal gland in Varanus niloticus (Nile monitor lizard), highlighting their structural features and adaptive mechanisms. Ten adult female Nile monitors were collected from Qena Province, Egypt, and their kidneys and adrenal glands were examined. Kidney tissues were processed for histological analysis, and immunohistochemistry was performed to evaluate the expression of key markers, including vimentin, E-cadherin, CK7, and NSE. In contrast to other reptiles, the kidney was divided into the cortex and medulla and contained a loop of Henle. The cortex contains renal corpuscles and nephron tubules, while the medulla primarily comprises collecting ducts. The proximal tubules were lined with acidophilic cuboidal cells, whereas the distal tubules exhibited pale cuboidal cells with fewer microvilli. Immunohistochemistry revealed vimentin expression in podocytes and a few renal tubule epithelial cells, while E-cadherin was expressed in the distal tubules, loop of Henle, and collecting ducts. NSE was strongly expressed in the renal corpuscles and macula densa of the juxtaglomerular apparatus, as well as in the peripolar cells, but was absent in the proximal tubules. CK7 was predominantly expressed in the distal tubules and collecting ducts. The adrenal glands comprise steroidogenic and chromaffin cells associated with the posterior cardinal veins of the kidney. NSE was strongly expressed in chromaffin cells, while vimentin was detected in steroidogenic cells. E-cadherin and CK7 are not expressed in the adrenal tissues. These findings provide insights into the structural and functional adaptations of the kidney and adrenal glands in Nile monitors, offering a foundation for future research into the comparative anatomy and functional ecology of reptilian excretory and endocrine systems.

Cartilage is a crucial component of the vertebrate skeletal system, providing structural integrity, flexibility, and adaptive functions across species. In teleost fish, cartilage exhibits significant morphological and functional diversity, providing specialized biomechanical properties essential for aquatic life. This study presents a detailed histological, immunohistochemical, and ultrastructural investigation of cartilage in molly fish (Poecilia sphenops), identifying five distinct types of cartilage: hyaline-cell, scleral, 

Background

Synanthropic filth flies thrive in human and animal habitats, posing health risks through the transmission of infectious agents. They breed on organic waste, including animal feces, making them carriers of various pathogens. In Egypt, where livestock farming is common and poor sanitation, these flies may contribute to zoonotic disease transmission. The current study investigates parasitic infections in filth flies from three livestock farms in Assiut Governorate, Upper Egypt, highlighting their role as vectors for zoonotic infections, particularly Cryptosporidium, via morphological and molecular tools.

Methods

A total of 12,749 flies were collected from the study sites via sweep nets. After taxonomic identification, the flies were examined microscopically for parasites using various concentration and staining techniques. Positive samples were further confirmed for infections, particularly for Cryptosporidium parasites, via nested PCR and sequence analysis targeting the COWP and SSU rRNA genes.

Results

This study revealed the presence of several fly species from seven dipteran families, particularly the family Muscidae, primarily Musca domestica, which presented a high parasite infestation rate of 96.6%. This study revealed a high prevalence of various protozoans and helminths in the collected flies. Cryptosporidium was the most prevalent parasite (64.4–100%), infecting all fly species. Entamoeba and Balantidium were also significant, especially in M. domestica (22.6–90.1%, 8.9–100%), Fannia canicularis (10.5–74.4%, 44.2–88.2%), and Borborillus vitripennis (11.1–50%, 37.2–91.4%). Giardia, Trichuris, and Trichostrongylidae had low to moderate prevalence in multiple fly species. Mites are commonly detected on fly exoskeletons, with high infestation rates observed in Musca domestica (77–100%) and Physiphora alceae (66.7–100%). The present study also reported sporadic infections with Trichomonas, Toxocara vitulorum, and pseudoscorpions, along with notable midge larval infestations (52.1%), mainly at site B. Parasitic infections were highest in autumn and spring, with the lowest rates in winter. Molecular identification confirmed the presence of the zoonotic species Cryptosporidium parvum and Cladotanytarsus gedanicus.

Conclusion

This study revealed that zoonotic parasites exist in flies and pose potential risks when they are found near humans. Cryptosporidium parvum is the prevalent parasite causing diarrhea outbreaks in animals. This is the first genetic evidence of Cladotanytarsus gedanicus midge from Upper Egypt.

Spermatogenesis in teleosts is essential for reproductive function; however, it varies considerably among species. The testis of the viviparous molly fish (Poecilia sphenops) was
examined using both ultrastructural and immunohistochemical methods. The testis displays a restricted lobular type, where germ cells develop synchronously within Sertoli
cell-forming cysts. Transmission electron microscopy (TEM) revealed all stages of spermatogenesis. Mature sperm are at the apex of the cysts and migrate toward the sperm
ducts. Sperm duct epithelium is lined by cuboidal cells joined by tight junctions, with
apical cilia and desmosomal complexes contributing to transport and structural integrity.
The sperm ducts showed strong Periodic Acid–Schiff (PAS)-positive expression among
negative stained spermatocysts. Centrally, a cavity serves as a storage area for spermatozoa
that are organized into unencapsulated bundles known as spermatozeugmata. Sertoli cells
exhibited extended cytoplasmic processes that supported developing germ cells, whereas
Leydig cells occupied the interstitial tissue, contributing to hormonal regulation. Immunohistochemical labeling demonstrated strong vimentin expression in Sertoli cells and
telocytes, indicating their mesenchymal origin and structural role. Calretinin expression
was confined to Leydig cells and certain ductal epithelial cells, supporting its use as a
marker for steroidogenic and secretory functions. These findings provide new insights into
the testicular specialization of P. sphenops, highlighting key somatic–germ cell interactions,
ductal adaptations, and marker expression patterns that underlie male reproductive success
in viviparous fish