1. Department of Reproductive Immunology and Pathology, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Tuwima Street, 10-748 Olsztyn, Poland
2. Institute of Veterinary Anatomy, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland
3. Graduate School of Natural Science and Technology, Okayama University, Tsushima Naka, Okayama 700-8530, Japan