1. Department of Biology, College of Science, Jouf University , Sakaka, Al-Jouf 72341 , Saudi Arabia
2. Department of Histology, Faculty of Veterinary Medicine, South Valley University , Qena 83523 , Egypt
3. Department of Cell and Tissues, Faculty of Veterinary Medicine, Assiut University , Assiut 71526 , Egypt
4. Department of Theriogenology, Faculty of Veterinary Medicine, New Valley University, El-kharga 71511, Egypt
5. Department of Anatomy and Embryology, Faculty of Veterinary Medicine, Alexandria University , Alexandria 21321 , Egypt