2020 article
miRNAs explain the variation in muscle and blood transcriptomes of beef calves born from dams with or without energy restriction during late gestation
Carvalho, E. B., Sanglard, L. P., Nascimento, M., Moriel, P., Sommer, J., Merrill, M., … Serao, N. (2020, November). JOURNAL OF ANIMAL SCIENCE, Vol. 98, pp. 165–165.
Abstract Maternal energy restriction during late gestation affects the expression of genes related to energy metabolism in muscle and immune response in blood. MicroRNAs (miRNAs) are short non-coding RNAs that regulate gene expression post-transcriptionally. The aim of this study was to identify potentials miRNA involved in the expression of differentially expressed genes (DEG) in muscle and blood following exposure to maternal gestational energy restriction. Forty days before the expected calving date, cows were assigned to one of two diets: 100% (CTRL) or 70% (REST) of the daily energy requirement. For RNA-seq analysis, muscle samples were collected from 12 heifers and 12 steers, and blood samples were collected from 12 steers. miRNAs were identified from the RNA-seq data based on the bovine genome annotation, with 38 and 10 miRNAs identified in blood and muscle, respectively. The expression of the miRNAs and the previously identified 160 and 450 DEGs in muscle and blood, respectively, was pre-adjusted for fixed effects before final analyses. A stepwise selection (P-value < 0.05) was used to identify miRNAs (dependent variables) explaining variation in DEGs, for each DEG at a time, and analyses performed separately for blood and muscle. The R2 of selected models ranged from 0.88 to 0.99 in muscle and 0.92 to 0.99 in blood. Of the most selected miRNA in muscle, MiR-133a and MiR-1 are known to be related to muscle hypertrophy, and MiR-143 and bta-let-7i promote adipocyte differentiation. Of the most selected miRNA in blood, MiR-21 regulates immune system by different pathways. Using RNA-seq data, we identified miRNAs explaining a large amount of the variation of DEGs, with the identification of important miRNAs related to muscle development and immune system.