Dynamic regulation of the transcriptome and proteome of the equine embryo during maternal recognition of pregnancy

Abstract

During initial maternal recognition of pregnancy (MRP), the equine embryo displays a series of unique events characterized by rapid blastocyst expansion, secretion of a diverse array of molecules, and transuterine migration to interact with the uterine surface. Up to date, the intricate transcriptome and proteome changes of the embryo underlying these events have not been critically studied in horses.

Embryo-endometrial interaction associated with the location of the embryo during the mobility phase in mares

“…In this study, the IPA analysis revealed that several genes could be influenced by the predicted upstream regulators, a pattern that aligns with the expression profiles of these regulators in a prior study on embryos 28 . Several genes associated with immune system regulation, including IFNG, CCL20, CXCL10, TNF, TNFAIP3 , and VCAM1 , were observed to be affected by the upstream regulators.…”

“…Several studies investigated the transcriptomic profile of the endometrium to gain further insight into the molecular events underlying embryo-maternal interactions during early pregnancy in mares 20 – 28 . The differentially expressed genes (DEGs) between pregnant and nonbred mares during early pregnancy were mainly associated with pathways related to the immune system, angiogenesis 21 , cell-to-cell interaction 26 , and prostaglandin regulation 23 .…”

A prospective study of the proteome of equine pre‐implantation embryo

“…This encompassed various ribosomal proteins, eukaryotic translation initiation factors, and proteins associated with translation. There is a marked association between equine embryo size and transcript abundance, as demonstrated by Vegas et al (2022). It is important to mention that this variation is influenced not only by intrinsic factors, such as embryo size variability (Cuervo-Arango et al, 2018), but also by maternal factors (Derisoud et al, 2023).…”

“…To the best of our knowledge, this is the first report of the proteome of the 8-day-old equine embryo. Recently, an elegant work conducted by Vegas et al (2022) reported the cluster of 2200 proteins in equine embryos from days 10 to 13 of gestation, with marked differences in protein expressions related to embryo size.…”

“…The 8‐cell stage is characterized by a dynamic up‐ and down‐regulation of gene expression, highlighting the complexity of transcription control (Goszczynski et al., 2021; Tachibana et al., 2009). This process is not solely directed by the embryo itself, but also by regulatory factors within the oviductal (Fernández‐Hernández et al., 2021) and uterine (Vegas et al., 2022) environments. The newly synthesized proteins play essential roles in both embryo development (Swegen et al., 2017) and communication with oviductal and uterine cells (Bastos et al., 2019).…”