D'Occhio Michael J, Campanile Giuseppe, Baruselli Pietro S
School of Life and Environmental Sciences, Faculty of Science, The University of Sydney, Sydney, NSW, Australia.
Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy.
Front Vet Sci. 2025 Aug 29;12:1651593. doi: 10.3389/fvets.2025.1651593. eCollection 2025.
The establishment of a pregnancy in cattle relies on crosstalk between an embryo with high developmental competence and a responsive uterus. This often fails and the pregnancy rate in cattle is around 60-70% with natural mating and 50-60% for embryo transfer, with pregnancies typically higher in beef than high performing dairy. These pregnancy rates are primarily due to the loss of embryos in the 21-day window from fertilization to the initiation of attachment of the conceptus to the uterus. Considerable research has been devoted to defining high quality embryos; however, embryonic mortality remains a major cause of pregnancy failure. The latter highlights the critical importance of uterine receptivity in establishing a pregnancy. The uterus must be responsive to signals from the developing embryo to undergo a major structural and functional transformation to prepare for attachment of the conceptus and establishment of pregnancy. The chemokine CXCL12 and its receptor CXCR4 are expressed across somatic and neural tissues and are associated with tissue remodeling including angiogenesis. These are features of the change the uterus undergoes as it develops receptivity to the conceptus. The developing embryo produces CXCL12 and CXCR4 is present in uterine tissue, and a role for the CXCL12-CXCR4 axis have been demonstrated in early pregnancy. Chemokines including CXCL12 are likely to be important in embryonic survival and pregnancy in cattle.
牛的妊娠建立依赖于具有高发育能力的胚胎与反应性子宫之间的相互作用。这种情况常常失败，牛自然交配的妊娠率约为60 - 70%，胚胎移植的妊娠率为50 - 60%，通常肉牛的妊娠率高于高产奶牛。这些妊娠率主要是由于从受精到孕体附着于子宫开始的21天窗口期内胚胎的损失。大量研究致力于定义高质量胚胎；然而，胚胎死亡仍然是妊娠失败的主要原因。后者凸显了子宫容受性在建立妊娠中的至关重要性。子宫必须对发育中胚胎发出的信号作出反应，经历重大的结构和功能转变，为孕体附着和妊娠建立做好准备。趋化因子CXCL12及其受体CXCR4在体细胞和神经组织中均有表达，并与包括血管生成在内的组织重塑相关。这些是子宫在发育出对孕体的容受性时所经历变化的特征。发育中的胚胎产生CXCL12，子宫组织中存在CXCR4，并且CXCL12 - CXCR4轴在早期妊娠中的作用已得到证实。包括CXCL12在内的趋化因子可能在牛的胚胎存活和妊娠中起重要作用。
