1. Division of Histology and Embryology, Department of Human Morphology and Embryology, Wroclaw Medical University, 50-368 Wroclaw, Poland
2. Prestage Department of Poultry Science, North Carolina State University, Raleigh, NC 27607, USA
3. Division of Anatomy, Department of Human Morphology and Embryology, Wroclaw Medical University, 50-368 Wroclaw, Poland
4. Fertility, Infertility and Perinatology Research Center, Ahvaz Jundishapur University of Medical Sciences, Ahvaz P.O. Box 6193673111, Iran
5. Department of Veterinary Surgery, Institute of Veterinary Medicine, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland
6. Department of Diagnostics and Clinical Sciences, Institute of Veterinary Medicine, Nicolaus Copernicus University in Torun, 87-100 Torun, Poland
7. Division of Ultrastructure Research, Department of Human Morphology and Embryology, Wroclaw Medical University, 50-368 Wroclaw, Poland
8. Physiology Graduate Faculty, North Carolina State University, Raleigh, NC 27613, USA
9. Department of Obstetrics and Gynecology, University Hospital and Masaryk University, 602 00 Brno, Czech Republic