Lipid Stores and Lipid Metabolism Associated Gene Expression in Porcine and Bovine Parthenogenetic Embryos Revealed by Fluorescent Staining and RNA-seq

Abstract

Compared to other mammalian species, porcine oocytes and embryos are characterized by large amounts of lipids stored mainly in the form of droplets in the cytoplasm. The amount and the morphology of lipid droplets (LD) change throughout the preimplantation development, however, relatively little is known about expression of genes involved in lipid metabolism of early embryos. We compared porcine and bovine blastocyst stage embryos as well as dissected inner cell mass (ICM) and trophoblast (TE) cell populations with regard to lipid droplet storage and expression of genes functionally annotated to selected lipid gene ontology terms using RNA-seq. Comparing the number and the volume occupied by LD between bovine and porcine blastocysts, we have found significant differences both at the level of single embryo and a single blastomere. Aside from different lipid content, we found that embryos regulate the lipid metabolism differentially at the gene expression level. Out of 125 genes, we found 73 to be differentially expressed between entire porcine and bovine blastocyst, and 36 and 51 to be divergent between ICM and TE cell lines. We noticed significant involvement of cholesterol and ganglioside metabolism in preimplantation embryos, as well as a possible shift towards glucose, rather than pyruvate dependence in bovine embryos. A number of genes like DGAT1, CD36 or NR1H3 may serve as lipid associated markers indicating distinct regulatory mechanisms, while upregulated PLIN2, APOA1, SOAT1 indicate significant function during blastocyst formation and cell differentiation in both models.

Proteomic Exploration of Porcine Oocytes During Meiotic Maturation in vitro Using an Accurate TMT-Based Quantitative Approach

“…However, we observed the highest level of TXNDC9 protein in porcine oocytes after IVM. Conversely, there are a large number of lipid droplets in porcine oocyte cytoplasm, which have been demonstrated to play a fundamental role in the oocyte maturation process by providing an energy source from lipid metabolism (42,43). Based on our results, many proteins were uncovered to participate in the signaling pathway of lipid metabolism during oocyte maturation such as methylsterol monooxygenase 1 (MSMO1), phospholipase A2 activating protein (PLAA), phosphatidate phosphatase (LPIN2), acetyl-CoA carboxylase 1 (ACACA), etc.…”

Transcriptome Analysis of mRNAs and Long Non-Coding RNAs During Subsequent Embryo Development of Porcine Cloned Zygotes After Vitrification

“…A total of 389 mRNAs and 816 lncRNAs were differentially expressed in the blastocysts developed from vitrified cloned zygotes. It is well known that lipid metabolism in the blastocyst stage is a fundamental function needed for subsequent implantation and placentation (Kajdasz et al, 2020). In this study, some GO terms related to lipid function were found to be enriched, such as 'high-density lipoprotein particle remodeling", lipoprotein particle", "negative regulation of very-low-density lipoprotein particle remodeling", "cholesterol homeostasis", "phospholipid efflux" and so on, and most of the involved mRNAs showed downregulation.…”

Intestinal tryptophan metabolism in disease prevention and swine production

“…In addition, lipid metabolism also affected the reproduction performance and shaped the quality of gametes and embryos in livestock. Upregulation of genes related to lipid metabolism such as perilipin 2, apolipoprotein A-1, and sterol O-acyltransferase-1 promoted lipid accumulation and enhanced blastocyst formation and cell differentiation in pigs and cows ( Kajdasz et al., 2020 ; Kelly et al., 2016 ).…”