Andersen Berg K, Filseth O, Engeland E
Department of Reproduction and Forensic Medicine, Veterinary College of Norway, Oslo, Norway.
Acta Vet Scand. 1996;37(3):367-73. doi: 10.1186/BF03548103.
A midpiece sperm defect with a frequency of 25-35% in ejaculates obtained from a Hereford bull with a 60 d non-return rate of 76.4% after careful pre- and post-freeze semen selection was studied in light microscope and by transmission electron microscopy. The defect consisted in a folding and coiling of the distal midpiece characterized by disorganization and irregularity of mitochondria surrounding the axial fiber bundle, combined with retraction of doublet fibers and dislocation and fracturing of these elements and the corresponding dense fibers. Based on examination of the spermatogenic epithelium it was concluded that the alterations in the axial fiber bundle were secondary to those in the mitochondrial sheath. The abnormality appeared to be related to the "Dag-like" defect earlier observed in different breeds.
从一头赫里福德公牛采集的精液中，中段精子缺陷的出现频率为25%-35%。在对冷冻前后的精液进行仔细筛选后，该公牛的60天不返情率为76.4%。利用光学显微镜和透射电子显微镜对这种缺陷进行了研究。该缺陷表现为远侧中段的折叠和盘绕，其特征是围绕轴纤维束的线粒体排列紊乱且不规则，同时伴有双联体纤维的回缩以及这些结构和相应致密纤维的错位和断裂。基于对生精上皮的检查得出结论，轴纤维束的改变继发于线粒体鞘的改变。这种异常似乎与先前在不同品种中观察到的“类达格”缺陷有关。
