Bartol F F, Wiley A A, Floyd J G, Ott T L, Bazer F W, Gray C A, Spencer T E
Department of Animal and Dairy Sciences, Auburn University, AL 36849-5415, USA.
J Reprod Fertil Suppl. 1999;54:287-302.
Uterine differentiation in cattle and sheep begins prenatally, but is completed postnatally. Mechanisms regulating this process are not well defined. However, studies of urogenital tract development in murine systems, particularly those involving tissue recombination and targeted gene mutation, indicate that the ideal uterine organizational programme evolves epigenetically through dynamic cell-cell and cell-matrix interactions that define the microenvironmental context within which gene expression occurs and may ensure adult tissue stability. In the cow and ewe, transient postnatal exposure of the developing uterus to steroids can produce immutable changes in adult uterine tissues that may alter the embryotrophic potential of the uterine environment. Thus, success of steroid-sensitive postnatal events supporting uterine growth and development can dictate the functional potential of the adult uterus. Studies to determine effects of specific steroidal agents on patterns of uterine development during defined neonatal periods, as well as the functional consequences of targeted neonatal steroid exposure in the adult uterus, should enable identification of critical developmental mechanisms and determinants of uterine integrity and function. Extreme adult uterine phenotypes (lesion models) created in cattle and sheep by strategic postnatal steroid exposure hold promise as powerful tools for the study of factors affecting uterine function and the rapid identification of novel uterine genes.
牛和羊的子宫分化在产前开始，但在产后完成。调节这一过程的机制尚未明确。然而，对小鼠系统中泌尿生殖道发育的研究，特别是那些涉及组织重组和靶向基因突变的研究表明，理想的子宫组织程序是通过动态的细胞间和细胞与基质间相互作用以表观遗传方式演变而来的，这些相互作用定义了基因表达发生的微环境背景，并可能确保成年组织的稳定性。在母牛和母羊中，发育中的子宫在产后短暂暴露于类固醇激素可在成年子宫组织中产生不可改变的变化，这可能会改变子宫环境的胚胎营养潜能。因此，支持子宫生长和发育的对类固醇敏感的产后事件的成功与否能够决定成年子宫的功能潜能。确定特定类固醇药物在特定新生期对子宫发育模式的影响，以及在成年子宫中进行靶向新生期类固醇暴露的功能后果的研究，应该能够确定子宫完整性和功能的关键发育机制和决定因素。通过产后策略性类固醇暴露在牛和羊中产生的极端成年子宫表型（病变模型）有望成为研究影响子宫功能的因素和快速鉴定新的子宫基因的有力工具。
