| Abstract: | Gonosomanomalies in mares and results of cytogenetic investigations in mares with major disturbances in fertility In the present study 28 mares with heavy disturbed fertility were examined on chromosome defects. Especially numerical anomalies on the gonosomes were taken into consideration. The preparation of the chromosomes was done by blood lymphocyte cultures. For that purpose blood tests were taken by the Venojekt** system. The preparations were stained by Giemsa- und c-band-technique. The caryotype by Hare 1980) served as the standard caryotype, by which at least 30 metaphases of each mare were analysed. The results of this examination are the following: 1. McCoy's 5A-medium with Hepes-supplement was suitable for the culture of lymphocytes for preparation of chromosomes of mares. 2. On the individual mitogenbatches important quality differences were stated. The mitogen Pokeweed turned out to be better qualified for the stimulation of lymphocytes than the mitogen Phytohaemagglutinin. 3. Good preparations resulted from the following medium-combination: 75% McCoy's 5A-medium with Hepes-buffer — 25% fetal calves' serum — 0, l ml Pokeweed as mi-togen. 4. Even after two days of storing the lymphocytes in the medium-combination good preparation results were obtained. 5. A modified staining-method for the presentation of c-bands respecting the exact identification of the gonosomes brought forth better results than the method of Schmidt (1976). 6. Although considerable fertility disturbances were present, not one gonosom anomaly was stated in the examined mares. |
