1. Department of Infertility and Reproductive Endocrinology, Poznan University of Medical Sciences, Poznan, Poland.
2. Department of Histology and Embryology, Poznan University of Medical Sciences, Poznan, Poland.
3. Department of Anatomy, Poznan University of Medical Sciences, Poznan, Poland.
4. Department of Obstetrics and Gynecology, University Hospital and Masaryk University, Brno, Czech Republic.
5. Veterinary Center, Nicolaus Copernicus University in Torun, Torun, Poland.
6. Division of Histology and Embryology, Department of Human Morphology and Embryology, Wroclaw Medical University, Wroclaw, Poland.
7. Division of Anatomy and Histology, University of Zielona Góra, Zielona Góra, Poland.