Remodeling of mammary tissue and lactation persistency

这项研究计划的长期目标是开发一种经济上可行、消费者可以接受的技术，以改善奶牛的哺乳持久性，并使奶牛能够更长时间地哺乳。从乳腺的角度来看，产奶量仅仅是分泌细胞数量和这些细胞的分泌活动的函数。在山羊中，分泌细胞的丧失是哺乳下降期间产奶量下降的原因。在啮齿动物和反刍动物中，现在已经很好地证实，在退化(哺乳终止)过程中，乳腺细胞的损失是通过程序性细胞死亡(细胞凋亡)发生的。细胞凋亡也发生在哺乳末期，并解释了泌乳下降时分泌细胞的进行性丧失。因此，有相当大的动机来确定调控乳腺细胞凋亡的因素，特别是在这些逐渐退化的早期阶段。

The long range objective of this research program is to develop an economically viable and consumer acceptable technology that would improve lactation persistency and enable longer lactation in dairy cows. From a mammary gland perspective, milk production is simply a function of the number of secretory cells and the secretory activity of these cells. In goats, it is the loss of secretory cells which accounts for the decrease in milk yield during declining lactation. It is now well established in rodents and ruminants that mammary cell loss during involution (termination of lactation) occurs through programmed cell death (apoptosis). Apoptosis also occurs in late lactation and accounts for the progressive loss of secretory cells in declining lactation. Therefore, there are considerable incentives to identify the factors that regulate mammary apoptosis, in particular during these early stages of gradual involution.