Genomics, transcriptomics and proteomics of the normal and abnormal equine placenta: A better understanding of late gestational function and dysfunction / Genômica, transcriptômica e proteômica da placenta equina normal e anormal: um melhor entendimento da função final da gestação e disfunção

High throughput methods to assess genomics, gene (mRNA) expression, and protein composition of tissues and body fluids has led to a rapid advancement in understanding of normal and abnormal function of many body systems across a wide variety of mammalian and non-mammalian animal species. Over the past several years, our laboratory has applied these techniques to the study of normal physiology and disease of the pregnant mare, in particular for the placenta and fetal fluids. Although our understanding of the endocrine aspects of pregnancy in mares is reasonably advanced, much of our understanding related to placental function and dysfunction remains limited. This review will cover a number of studies which detail normal gestational changes in the fetal and maternal placenta along with changes in gene expression in a number of late gestational diseases of pregnancy.

Effects of a systemic high urea concentration on the endometrial and embryonic transcriptome of mares / Efeitos de concentrações sistêmicas elevadas de ureia no transcriptoma do endométrio e embriões de éguas

It has been shown in ruminants that increased dietary protein leading to elevated blood urea nitrogen concentrations (BUN) can be a factor in decreased survival of early embryos. This work is a review of the effects of elevated BUN on endometrium and embryos from mares. An experimental model was used to elevate BUN with intravenous urea infusion, acute treatment, or oral urea, chronic treatment. After the acute urea treatment there was a decrease in uterine pH and changes in genes related to cell pH and ion homeostasis. After the chronic urea treatment there was no difference in uterine pH but genes related to necrosis and cellular movement had a different expression. The effect of high BUN was also evaluated on equine embryo transcriptome, with a positive correlation between plasma BUN and blastocoele fluid urea nitrogen concentration. Additionally, the expression of genes related to survival of organism and adhesion were different. Lastly, using mares from private farms, lower pregnancy rate was seen when embryos were collected from mares with higher BUN concentrations. In conclusion, these novel results show that high BUN results in endometrial and embryonic alterations, suggesting that it might lead to decreased fertility.