BACKGROUND Alterations in maternal environment can sometimes affect embryonic development in a sexually-dimorphic manner. The objective was to determine whether preimplantation bovine embryos respond to three maternally-derived cell signaling molecules in a sex-dependent manner. RESULTS Actions of three embryokines known to increase competence of bovine embryos to develop to the blastocyst stage, insulin-like growth factor 1 (IGF1), activin A, and WNT member 7A (WNT7A), were evaluated for actions on embryos produced in vitro with X- or Y- sorted semen from the same bull. Each embryokine was tested in embryos produced by in vitro fertilization of groups of oocytes with either pooled sperm from two bulls or with sperm from individual bulls. Embryos were treated with IGF1, activin A, or WNT7A on day 5 of culture. All three embryokines increased the proportion of cleaved zygotes that developed to the blastocyst stage and the effect was similar for female and male embryos. As an additional test of sexual dimorphism, effects of IGF1 on blastocyst expression of a total of 127 genes were determined by RT-qPCR using the Fluidigm Delta Gene assay. Expression of 18 genes was affected by sex, expression of 4 genes was affected by IGF1 and expression of 3 genes was affected by the IGF1 by sex interaction. CONCLUSION Sex did not alter how IGF1, activin A or WNT7A altered developmental competence to the blastocyst stage. Thus, sex-dependent differences in regulation of developmental competence of embryos by maternal regulatory signals is not a general phenomenon. The fact that sex altered how IGF1 regulates gene expression is indicative that there could be sexual dimorphism in embryokine regulation of some aspects of embryonic function other than developmental potential to become a blastocyst.

中文翻译：

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性别对牛植入前胚胎对胰岛素样生长因子1，激活素A和WNT7A反应的影响。

背景技术母体环境的改变有时会以性二态性影响胚胎发育。目的是确定植入前的牛胚胎是否以性别依赖的方式对三个母体来源的细胞信号分子产生反应。结果评估了三种已知能增加牛胚胎发育至胚泡阶段能力的胚胎因子，胰岛素样生长因子1（IGF1），激活素A和WNT成员7A（WNT7A）的作用，这些作用是通过体外培养产生的。来自同一头公牛的X或Y型精液。每个胚胎因子都在通过体外受精的卵子组中的卵进行测试，这些卵母细胞具有来自两个公牛的合并的精子或来自各个公牛的精子。在培养的第5天用IGF1，激活素A或WNT7A处理胚胎。所有这三种胚胎因子均增加了发育至胚泡期的分裂受精卵的比例，男女胚胎的作用相似。作为性二态性的另一项测试，使用Fluidigm Delta基因测定法通过RT-qPCR确定了IGF1对总共127个基因的胚泡表达的影响。性别影响18个基因的表达，IGF1影响4个基因的表达，IGF1影响3个基因的表达。结论性未改变IGF1，激活素A或WNT7A如何改变发育至胚泡期的能力。因此，通过母体调节信号调节胚胎发育能力的性别依赖性差异不是普遍现象。