Peri-implantation gestational day 11 porcine embryos

Asynchrony of trophectoderm elongation, gestational days 11-12, is evident in porcine concepti and, rapid progression through this phase has been associated with conceptus competency. The goal of the current study was to determine the extent of transcriptomic responses of concepti to developmental delay and their physiological implications. Concepti with the same morphology, ovoid and 7-8 mm, were isolated and designated as normal or developmentally delayed if collected from a homogenous ovoid conceptus population or a heterogeneous conceptus population (ovoid to filamentous), respectively. Total RNA prepared from 4 distinct normal and 4 distinct developmentally delayed concepti, was analyzed using an Agilent high-density custom porcine microarray. Two hundred-nine transcripts were found differentially expressed between normal and developmentally delayed concepti. Functional analysis of these genes indicated that a significant number of the genes regulate signal transduction/transcription, organismal development, metabolism, and cell adhesion and can be modulated by transforming growth factor β1. Ten genes were selected for real-time PCR validation of differential expression based on a known role in steroid synthesis, endometrium receptivity, and modulation of trophoblast differentiation/growth or interaction with transforming growth factor β1. As in the microarray, all except one, achaete-scute complex homolog 2, were preferentially up-regulated in delayed concepti. Overall, the findings suggested that developmentally delayed concepti are distinct from their morphologically similar counterparts and more developmentally advanced concepti. Furthermore, it also highlighted ways by which the conceptus’ microenvironment might be affected and pinpointed developmental factors that can be interrogated further to determine if, and how, they affect embryo competency/elongation. Overall design: Gene expression of developmentally delayed day ~ 11.5 ovoid embryos from a heterogeneous embryo population was compared to day 11 ovoid embryos from a homogeneous embryo popluation. An n of 4 was compared for each group with the embryos from the homogenous population being the control and those from the heterogeneous population the experimental. The interest was to see where morphology or the uterine environment was a better predictor of the transcriptome profile and its implications on the development potential/compentence of the the developmentally delayed embryo. Self-self hybridizations for control and experimental samples.