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.

猪胎儿的滋养层伸长异步性在妊娠第11-12天明显可见，此阶段快速进展与胎儿发育成熟度相关联。本研究旨在确定胎儿对发育延迟的转录组响应范围及其生理学意义。形态相同的胎儿（椭圆形，直径7-8毫米），若来自同质椭圆形胎儿群体则被指定为正常，若来自异质胎儿群体（椭圆形至丝状）则被指定为发育延迟。从4个不同的正常和4个不同的发育延迟胎儿中制备的总RNA，使用Agilent高密度定制猪微阵列进行分析。在正常和发育延迟胎儿之间发现了209个差异表达的转录本。对这些基因的功能分析表明，大量基因调节信号转导/转录、生物体发育、新陈代谢、细胞粘附，并可受转化生长因子β1调节。基于已知在类固醇合成、子宫内膜容受性、滋养层分化/生长调节或与转化生长因子β1相互作用中的作用，选取了10个基因进行基于实时PCR的差异表达验证。与微阵列结果一致，除了一种（achaete-scute复合体同源物2）外，所有基因在延迟发育的胎儿中均优先上调。总体而言，研究结果提示发育延迟的胎儿与其形态相似的同类胎儿及发育更成熟的胎儿存在差异。此外，它还突显了胎儿微环境可能受到影响的方式，并指出了可以进一步探究以确定其是否以及如何影响胚胎发育成熟度/伸长的发育因素。总体设计：来自异质胚胎群体的发育延迟的第11.5天椭圆形胚胎的基因表达与来自同质胚胎群体的第11天椭圆形胚胎的基因表达进行了比较。每组各比较了4个n值，同质群体的胚胎作为对照组，而异质群体的胚胎作为实验组。研究旨在观察形态或子宫内膜环境哪个更能预测转录组轮廓及其对发育潜力/成熟度的影响。对照和实验样本均进行了自我杂交。