Bosma A A, Elgersma A, de Haan N A
Tijdschr Diergeneeskd. 1987 Jul 1;112(13):789-94.
Three hundred young Dutch Friesian and Holstein-Friesian bulls, kept in the Central Opfokstation (Central Breeding Station) in Terwispel (Friesland), were studied cytogenetically, using conventional staining methods. Structural chromosome aberrations were not observed. Four animals showed XX/XY-chimerism in the lymphocytes, probably caused by the interchange of haemopoietic cells between the male and its female co-twin by placental vascular anastomosis. The number of (iso)chromatid gaps in 25 metaphase plates varied from 0 to 4. Chromosome breaks were not observed. The chimeric bulls and those with (iso)chromatid gaps were not found to show significantly reduced fertility rates.
对饲养在特维斯佩尔（弗里斯兰省）中央育种站的300头荷兰弗里西亚公牛和荷斯坦 - 弗里西亚公牛进行了细胞遗传学研究，采用传统染色方法。未观察到染色体结构畸变。四只动物的淋巴细胞呈现XX/XY嵌合现象，这可能是由于胎盘血管吻合导致雄性与其雌性孪生体之间造血细胞的交换所致。25个中期板中的（等）染色单体间隙数量从0到4不等。未观察到染色体断裂。未发现嵌合公牛和有（等）染色单体间隙的公牛的生育率显著降低。
