Submitted to: Society for the Study of Reproduction Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: April 17, 2009
Publication Date: June 15, 2009
Citation: Blomberg, L., Schreier, L.L., Li, R. 2009. Characteristics of Peri-Implantation Porcine Concepti Population Influence Transcriptome Profile. Biological Reproduction 81 (Suppl 1) p. 57, #41. Technical Abstract: Asynchrony of trophectoderm elongation during the rapid early elongation, days 11-12, is evident in porcine concepti and precocious progression through this phase has been associated with conceptus competency. The goal of the current study was to determine if the transcriptome of morphologically similar but developmentally delayed peri-implantation porcine concepti was altered and if those changes may be an indicator of conceptus competency. Concepti of the same morphology on gestational day 11, ovoid and 7-8 mm, were isolated and designated as developmentally normal, if collected from a homogenous population of ovoid concepti, or developmentally delayed, if present in a heterogeneous population of concepti, where the majority were advanced tubular or filamentous concepti. Concepti from both categories were collected from independent animals on different days and custom designed (Agilent eArray) porcine-specific 4 x 44K microarrays were hybridized with mRNA from 4 distinct normal concepti and 4 distinct delayed concepti. A total of 209 transcripts were found to be differentially expressed between the two concepti populations. Gene ontology analysis indicated that these transcripts encoded proteins involved in the regulation of transcription, signal transduction, transport, multi-cellular organism development, lipid metabolism, cell adhesion, metabolism and estrogen synthesis. Functional analysis of identified genes with Ingenuity Pathway analysis software indicated that a significant number of genes, assigned to the regulation of cell death, can be regulated by estrogen. Validation of differential gene expression by real-time PCR indicated that transcripts encoding proteins involved in estrogen synthesis and the positive regulation of apoptosis (insulin-like growth factor binding protein 3 and transforming growth factor beta 1 and 3) were preferentially up-regulated in delayed concepti. In keeping with delayed trophectoderm development seen in delayed concepti, the mRNA level of a negative regulator of placental development (H19) and a positive modulator of trophoblast differentiation was induced and suppressed, respectively. These findings suggest that concepti cannot be considered the same based on morphology alone and, the uterine microenvironment has a tremendous effect on the transcriptome of the porcine conceptus. Thus, this study has pinpointed potential physiological pathways that can be interrogated further to determine specific mechanism(s) that may affect embryo competency and elongation of the extra-embryonic trophectoderm.