School of Agriculture and Food Science,University College Dublin,Dublin,D04N2E5,Ireland.
Animal. 2018 Jun;12(s1):s4-s18. doi: 10.1017/S175173111800071X. Epub 2018 Apr 12.
Up to the 18th century, the prevailing view of reproduction, or 'generation' as it was referred to, was that organisms develop from miniatures of themselves, termed preformation. The alternative theory, epigenesis, proposed that the structure of an animal emerges gradually from a relatively formless egg. The teachings of the Ancient Greeks who argued either that both sexes each contributed 'semen' to form the embryo, or held a more male-centred view that the female merely provided fertile ground for the male seed to grow, dominated thinking until the 17th century, when the combined work of numerous scholars led to the theory that all female organisms, including humans, produced eggs. The sequence of events leading to the commercial use of artificial insemination (AI) date back to the discovery of sperm in 1678, although it took almost 100 years to demonstrate that sperm were the agents of fertilisation and a further 100 years for the detailed events associated with fertilisation to be elucidated. The first successful AI, carried out in the dog, dates back to 1780 while it was not until the early to mid-1900s that practical methods for AI were described in Russia. Inspired by the Russian success, the first AI cooperative was established in Denmark in 1936 and later in the United States in 1938. The next major advances involved development of semen extenders, addition of antibiotics to semen, and the discovery in 1949 that glycerol protected sperm during cryopreservation. Almost four decades later, the flow cytometric separation of X- and Y-bearing sperm opened a new chapter in the application of AI for cattle breeding. As we look forward today, developments in imaging sperm and breakthroughs in gene editing and stem cell technology are opening up new possibilities to manipulate reproduction in a way never thought possible by the pioneers of the past. This review highlights some of the main milestones and individuals in the history of sperm biology and the development of technologies associated with AI in cattle.
直到 18 世纪，人们普遍认为生物的繁殖或“生殖”是由自身的微型物（称为预成论）发展而来的。另一种理论，即后成论，提出动物的结构是从相对无定形的卵中逐渐出现的。古希腊人争论说，两性都各自贡献“精液”来形成胚胎，或者持有更以男性为中心的观点，即女性只是为男性的种子提供肥沃的土壤来生长，这种观点主导了人们的思维，直到 17 世纪，众多学者的综合研究成果导致了这样一种理论，即所有女性生物，包括人类，都产生卵子。导致人工授精（AI）商业化使用的一系列事件可以追溯到 1678 年精子的发现，尽管几乎花了 100 年的时间才证明精子是受精的媒介，又花了 100 年的时间才阐明与受精相关的详细事件。第一例成功的 AI 是在狗身上进行的，可以追溯到 1780 年，而直到 20 世纪初，俄罗斯才描述了 AI 的实用方法。受俄罗斯成功的启发，1936 年丹麦成立了第一家 AI 合作机构，后来在 1938 年美国也成立了。下一个重大进展涉及精液扩展剂的开发、精液中添加抗生素以及 1949 年发现甘油在冷冻保存过程中保护精子。近四十年后，流式细胞术分离携带 X 和 Y 染色体的精子为牛的 AI 应用开辟了一个新篇章。当我们展望未来时，精子成像技术的发展以及基因编辑和干细胞技术的突破，为过去的先驱者从未想过的繁殖操纵开辟了新的可能性。本文回顾了精子生物学历史上的一些主要里程碑和个人，以及与 AI 相关的技术的发展。
