Mobberley M A
Electron Microscopy Unit, Department of Histopathology, Charing Cross Hospital, Fulham Palace Road, London W6 8RF, UK.
Br J Biomed Sci. 2010;67(2):92-100. doi: 10.1080/09674845.2010.11730302.
Asthenozoospermia, defined as low sperm motility, is a significant cause of subfertility in men. Its origins are diverse and in some instances cannot be ascertained. However, severely reduced motility can often be associated with abnormalities in the structure of the sperm tails, which can only be detected by transmission electron microscopy (TEM). In this respect, TEM is an important adjunct to the traditional methods of semen analysis. This review examines the development of the current state of knowledge of sperm tail abnormalities. These may be genetic in origin, or they may be acquired as a result of extrinsic factors. At present, consistent molecular markers are not available to characterise many of the genetic defects. However, TEM can distinguish specific defects of genetic origin and the non-specific structural anomalies that are typical of an acquired condition. It can also differentiate sperm structural anomalies from necrospermia, or sperm death, which is another significant cause of asthenozoospermia. In this modern era of assisted reproduction, it is possible in some instances to circumvent the problems of sperm immotility and to achieve fertilisation and pregnancy using intracytoplasmic sperm injection (ICSI). However, because of the possible genetic origin of asthenozoospermia, many scientists working in the field of infertility believe that it is of the utmost importance to investigate the causes of asthenozoospermia. This review considers the continuing relevance of TEM to the evaluation of sperm tail abnormalities in the context of current reproductive techniques.
弱精子症定义为精子活力低下，是男性生育力低下的一个重要原因。其病因多种多样，在某些情况下无法确定。然而，活力严重降低往往与精子尾部结构异常有关，而这只能通过透射电子显微镜（TEM）检测到。在这方面，TEM是传统精液分析方法的重要辅助手段。本综述探讨了精子尾部异常的当前知识状态的发展。这些异常可能源于遗传，也可能是外部因素导致的。目前，尚无一致的分子标记可用于表征许多遗传缺陷。然而，TEM可以区分遗传起源的特定缺陷和后天性疾病典型的非特异性结构异常。它还可以将精子结构异常与死精症（即精子死亡）区分开来，死精症是弱精子症的另一个重要原因。在这个辅助生殖的现代时代，在某些情况下可以规避精子活力不足的问题，并通过胞浆内单精子注射（ICSI）实现受精和怀孕。然而，由于弱精子症可能源于遗传，许多从事不孕症领域研究的科学家认为，调查弱精子症的病因至关重要。本综述在当前生殖技术的背景下考虑了TEM对评估精子尾部异常的持续相关性。
