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Harnessing information from the maternal blood to predict fetal growth is attractive yet scarcely explored in livestock. The objectives were to determine the transcriptomic modifications in maternal blood and fetal liver, gonads, and heart according to fetal weight and to model a molecular signature based on the fetal organs allowing the prediction of fetal weight from the maternal blood transcriptome in cattle. In addition to a contemporaneous maternal blood sample, organ samples were collected from 10 male fetuses at 42 days of gestation for RNA-sequencing. Fetal weight ranged from 1.25 to 1.69 g (mean = 1.44 ± 0.15 g). Clustering data analysis revealed clusters of co-expressed genes positively correlated with fetal weight and enriching ontological terms biologically relevant for the organ. For the heart, the 1346 co-expressed genes were involved in energy generation and protein synthesis. For the gonads, the 1042 co-expressed genes enriched seminiferous tubule development. The 459 co-expressed genes identified in the liver were associated with lipid synthesis and metabolism. Finally, the cluster of 571 co-expressed genes determined in maternal blood enriched oxidative phosphorylation and thermogenesis. Next, data from the fetal organs were used to train a regression model of fetal weight, which was predicted with the maternal blood data. The best prediction was achieved when the model was trained with 35 co-expressed genes overlapping between heart and maternal blood (root-mean-square error = 0.04, R2= 0.93). In conclusion, linking transcriptomic information from maternal blood with that from the fetal heart unveiled maternal blood as a predictor of fetal development.Co-expressed genes positively correlated with fetal weight at 42 days were biologically relevant for the organ. The maternal blood transcriptome accurately predicted fetal weight after modeling with the fetal heart data.Graphical Abstract

Embryo transfer in cattle and other species is a key reproductive technology to improve genetic merit. However, pregnancy loss after embryo transfer is still a major barrier to optimal utilization of the technology. Furthermore, the lack of a method to objectively quantify embryonic competence hinders investigations aimed at improving the competence of an embryo. Based on the knowledge that bovine embryos have an inherent molecular signature that determines their ability for pregnancy establishment which can result in distinct gene expression profiles, we have previously integrated transcriptomic data from independent experiments to identify eight genes capable of predicting embryo competence for survival with high accuracy. In this study, we developed a function for the R software containing a mathematical formula based on the model coefficients to yield an embryonic competence index (ECI) according to the expression of those eight critical genes. Application of the function to a gene expression dataset generates a quantitative ECI value for each embryo that can be employed in statistical analyses when performing an experiment. The folder with the R project and required datasets can be found in https://zenodo.org/records/12515587.

Triclosan (TCS), an antibacterial compound commonly added to personal care products, could be an endocrine disruptor at low doses. Although TCS has been shown to alter fetal physiology, its effects in the developing fetal brain are unknown. We hypothesize that exposure to TCS during fetal life could affect fetal hypothalamic gene expression. The objective of this study was to use transcriptomics and systems analysis to identify significantly altered biological processes in the late gestation ovine fetal hypothalamus after direct or indirect exposure to low doses of TCS. For direct TCS exposure, chronically catheterized late gestation fetal sheep were infused with vehicle (n = 4) or TCS (250 μg/d; n = 4) iv. For indirect TCS exposure, TCS (100 μg/kg · d; n = 3) or vehicle (n = 3) was infused into the maternal circulation. Fetal hypothalami were collected after 2 days of infusion, and gene expression was measured through microarray. Hierarchical clustering of all samples according to gene expression profiles showed that samples from the TCS-treated animals clustered apart from the controls. Gene set enrichment analysis revealed that fetal hypothalamic genes stimulated by maternal and fetal TCS infusion were significantly enriching for cell cycle, reproductive process, and feeding behavior, whereas the inhibited genes were significantly enriching for chromatin modification and metabolism of steroids, lipoproteins, fatty acids, and glucose (P< .05). In conclusion, short-term infusion of TCS induces vigorous changes in the fetal hypothalamic transcriptomics, which are mainly related to food intake pathways and metabolism. If these changes persist to postnatal life, they could result in adverse consequences in adulthood.