Effect of Maternal Methionine Supplementation on the Transcriptome of Bovine Preimplantation Embryos

Abstract

Maternal nutrition exclusively during the periconceptional period can induce remarkable effects on both oocyte maturation and early embryo development, which in turn can have lifelong consequences. The objective of this study was to evaluate the effect of maternal methionine supplementation on the transcriptome of bovine preimplantation embryos. Holstein cows were randomly assigned to one of two treatments differing in level of dietary methionine (1.89 Met vs. 2.43 Met % of metabolizable protein) from calving until embryo flushing. High quality preimplantation embryos from individual cows were pooled and then analyzed by RNA sequencing. Remarkably, a subtle difference in methionine supplementation in maternal diet was sufficient to cause significant changes in the transcriptome of the embryos. A total of 276 genes out of 10,662 showed differential expression between treatments (FDR <0.10). Interestingly, several of the most significant genes are related to embryonic development (e.g., VIM, IFI6, BCL2A1, and TBX15) and immune response (e.g., NKG7, TYROBP, SLAMF7, LCP1, and BLA-DQB). Likewise, gene set enrichment analysis revealed that several Gene Ontology terms, InterPro entries, and KEGG pathways were enriched (FDR <0.05) with differentially expressed genes involved in embryo development and immune system. The expression of most genes was decreased by maternal methionine supplementation, consistent with reduced transcription of genes with increased methylation of specific genes by increased methionine. Overall, our findings provide evidence that supplementing methionine to dams prior to conception and during the preimplantation period can modulate gene expression in bovine blastocysts. The ramifications of the observed gene expression changes for subsequent development of the pregnancy and physiology of the offspring warrant further investigation in future studies.

Differential expression of genes related with meat tenderness in Nellore cattle

“…The average of reads obtained for each group can be visualized in Table 2. An average of 70% of the reads were mapped by TopHat, which is similar to other studies, such as PEÑAGARICANO et al (2013) in a study on embryos that had an average of 75% of the total reads mapped using two mismatches. The uniquely aligned reads by software HTSeq had a mean number of approximately 61% (Table 2).…”

Cell Signalling During Blastocyst Morphogenesis

“…Pathway analysis revealed that genes involved in embryo development and the immune system were enriched within the differentially expressed set. Affected genes were mostly decreased, consistent with reduced transcription of genes with increased methylation of specific genes by increased methionine availability (Penagaricano et al 2013). …”

“…Consequences of manipulation of methyl group availability by maternal dietary challenge can become apparent as early as the blastocyst stage. In a bovine model (Penagaricano et al 2013) a subtle difference in maternal dietary methionine supplementation was sufficient to change the transcriptome of the embryos significantly. Pathway analysis revealed that genes involved in embryo development and the immune system were enriched within the differentially expressed set.…”

An application of Me SH enrichment analysis in livestock

“…The central hypothesis tested in Peñagaricano et al . () study using RNA‐seq was that maternal methionine supplementation around conception can produce epigenetic changes (e.g., DNA methylation) in the fetal genome leading to changes in gene expression in early embryos. A subset of enriched MeSH terms significant at 5% ( P ≤ 0.05) associated with genes in which expression was altered by maternal methionine supplementation in dairy cattle is presented in Table .…”

“…Briefly, these three datasets provide (i) genes that showed differential expression in preimplantation embryos due to maternal methionine supplementation in dairy cattle (Peñagaricano et al . ), (ii) genes from major QTL associated with age at puberty in gilts (Tart et al . ) and (iii) genes under selection in the Quarter Horse (Petersen et al .…”