J Anim Sci. 2017 Dec;95(12):5639-5652. doi: 10.2527/jas2017.1875.
The latter half of the 20th century and the early portion of the 21st century will be recognized as the "Golden Age" of lactation biology. This period corresponded with the rise of systemic, metabolomic, molecular, and genomic biology. It includes the discovery of the structure of DNA and ends with the sequencing of the complete genomes of humans and all major domestic animal species including the dairy cow. This included the ability to identify polymorphisms in the nucleic acid sequence, which can be tied to specific differences in cellular, tissue, and animal performance. Before this period, classical work using endocrine ablation and replacement studies identified the mammary gland as an endocrine-dependent organ. In the early 1960s, the development of RIA and radioreceptor assays permitted the study of the relationship between endocrine patterns and mammary function. The ability to measure nucleic acid content of tissues opened the door to study of the factors regulating mammary growth. The development of high-speed centrifugation in the 1960s allowed separation of specific cell organelles and their membranes. The development of transmission and scanning electron microscopy permitted the study of the relationship between structure and function in the mammary secretory cell. The availability of radiolabeled metabolites provided the opportunity to investigate the metabolic pathways and their regulation. The development of concepts regarding the coordination of metabolism to support lactation integrated our understanding of nutrient partitioning and homeostasis. The ability to produce recombinant molecules and organisms permitted enhancement of lactation in farm animal species and the production of milk containing proteins of value to human medicine. These discoveries and others contributed to vastly increased dairy farm productivity in the United States and worldwide. This review will include the discussion of the centers of excellence and scientists who labored in these fields to produce the harvest of knowledge we enjoy today.
20 世纪后半叶和 21 世纪初将被认为是哺乳生物学的“黄金时代”。这一时期与系统生物学、代谢组学、分子生物学和基因组生物学的兴起相对应。它包括 DNA 结构的发现，一直持续到人类和所有主要家畜物种（包括奶牛）的完整基因组测序。这包括能够识别核酸序列中的多态性，这些多态性可以与细胞、组织和动物性能的特定差异联系起来。在此之前，使用内分泌消融和替代研究的经典工作已经确定了乳腺是一种内分泌依赖性器官。20 世纪 60 年代初，RIA 和放射受体测定法的发展使得研究内分泌模式与乳腺功能之间的关系成为可能。测量组织中核酸含量的能力为研究调节乳腺生长的因素打开了大门。20 世纪 60 年代高速离心的发展允许分离特定的细胞细胞器及其膜。透射和扫描电子显微镜的发展允许研究乳腺分泌细胞的结构与功能之间的关系。放射性标记代谢物的可用性提供了研究代谢途径及其调节的机会。关于协调代谢以支持泌乳的概念的发展整合了我们对营养分配和体内平衡的理解。生产重组分子和生物体的能力允许增强家畜物种的泌乳能力，并生产含有对人类医学有价值的蛋白质的牛奶。这些发现和其他发现极大地提高了美国和全球的奶牛场生产力。本综述将包括讨论卓越中心和在这些领域工作的科学家，以产生我们今天所享有的知识成果。
