Transcriptomic profiles of uniform populations of in vivo-produced spherical, ovoid, or tubular porcine embryos during the initiation of elongation

Authors: WALSH, SOPHIE - University Of Nebraska; Miles, Jeremy; Wright, Elane; Keel, Brittney; Rempel, Lea; PANNIER, ANGELA - University Of Nebraska

Submitted to: Reproduction, Fertility and Development
Publication Type: Abstract Only
Publication Acceptance Date: 8/1/2019
Publication Date: 12/2/2019
Citation: Walsh, S., Miles, J.R., Wright-Johnson, E.C., Keel, B.N., Rempel, L.A., Pannier, A.K. 2019. Transcriptomic profiles of uniform populations of in vivo-produced spherical, ovoid, or tubular porcine embryos during the initiation of elongation [abstract]. Reproduction, Fertility and Development. 32(2):152. https://doi.org/10.1071/RDv32n2Ab53.
DOI: https://doi.org/10.1071/RDv32n2Ab53

Interpretive Summary:

Technical Abstract: Signaling interactions among littermate porcine conceptuses during embryo elongation can alter the expression of genes that are essential in promoting successful embryo elongation. Understanding the differential expression of critical genes from uniform littermate conceptuses as they undergo the initiation of elongation can help identify critical pathways and genes to facilitate improved synchronization of embryo elongation and birthweight uniformity. The objective of this study was to identify differential gene expression from uniform porcine conceptuses as they transition through spherical (S), ovoid (O), and tubular (T) morphologies during the initiation of elongation in vivo. White crossbred gilts (n = 22) were bred at estrus (designated as day 0 of gestation) and harvested at day 9, 10, or 11 of gestation to obtain corresponding uniform populations of each embryo morphology. Reproductive tracts were immediately collected and flushed with 40 mL of RPMI-1640 medium. Based on morphology, embryos were assigned to one of three treatment groups: (1) uniform S (n = 8); (2) uniform O (n = 8); or (3) uniform T (n = 6) in which at least 80% of the embryos within each litter corresponded to the latest stage morphology. RNA-Seq was performed from 22 libraries constructed from in vivo-produced embryos from the uniform populations of S, O, or T embryos. Differentially expressed genes (DEG) and pathway analysis were evaluated using DESeq2 and iPathwayGuide, respectively. For the S vs. O comparison, there were 5726 DEG and 7 pathways were significantly enriched, including ribosome biogenesis, spliceosome, pyrimidine metabolism, RNA polymerase, one carbon pool by folate, ECM-receptor interaction, and MAPK signaling pathways. For the S vs. T comparison, there were 5914 DEG and 7 pathways that were significantly enriched, including ribosome biogenesis, DNA replication, pyrimidine metabolism, cell cycle, mismatch repair, spliceosome, and one carbon pool by folate pathways. Interestingly, most of the transcripts in pathways involving DNA processing, nucleotide metabolism, transcription, and post-transcriptional modifications were upregulated in S embryos compared with O and T embryos. For the O vs. T comparison, only 20 DEG were identified and no pathways were found to be significant after FDR adjustment. These data illustrate dramatic changes in the transcriptomes from pre-elongation stage S embryos compared with transitional stage O and T embryos, and provide putative genes and pathways involved in internal signals for the initiation of embryo elongation in pigs. USDA is an equal opportunity provider and employer. Funding provided by USDA-NIFA-AFRI Grant no. 2017-67015-26456.