1. Department of Histology and Cytology, Faculty of Veterinary Medicine, University of Sadat City, Sadat City, Egypt
2. Department of Anatomy, Faculty of Veterinary Medicine, Mansoura University, Mansoura, Egypt
3. Department of Biology, College of Science, Jouf University, Sakakah, Saudi Arabia
4. Department of Zoology, Faculty of Science, Fayoum University, Fayoum, Egypt