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Pregnancy Associated Glycoproteins as Insights Into Late Embryonic Development and Mortality in Beef Cattle
No full textIn ruminants, placenta fusion involves the movement of Trophoblast Giant Cells toward the endometrial epithelium and the subsequent release of Pregnancy Associated Glycoproteins (PAGs) by these cells. PAGs travel to the uterine stroma, eventually reaching a blood vessel and entering maternal circulation. Pregnant cows with lower PAG concentrations face a greater risk of late embryonic mortality, but the exact role of PAGs in these losses has never been fully understood. First, we used an in vivo model to compare the transcriptome and histological features of reproductive tissues in pregnancies with High and Low PAG levels. The results indicated significant differences in peripheral PAG concentrations between the High and Low PAG groups, but no disparities were observed in PAG expression or localization within the placenta. Gene ontology analyses revealed that High and Low PAG groups differed in processes associated with extracellular matrix (ECM) remodeling, molecule transport across the endometrium and placenta, synthesis of prostaglandins and endometrial immune responses. In vivo, PAGs did not significantly impact the transcriptome of the corpus luteum (CL). Subsequently, we conducted experiments to assess if these processes would exhibit alterations in an ex vivo setting. Explants from the endometrium, trophectoderm, and CL were cultured under different conditions: without PAG, with High PAG, and with Low PAG, each with or without progesterone (P4), using a 2 x 3 factorial arrangement. The results demonstrated increased P4 availability, enhanced Prostaglandin F2�� synthesis, improved nutrient supply to the conceptus, potential regulation of immune responses, and enhanced trophoblast fusogenic capability. Furthermore, PAG treatments appeared to influence changes in CL endocrine responses, leading to greater P4 synthesis, but with no alterations in prostaglandin E2. The addition of P4 to the culture media did not impact the outcomes. These studies led us to hypothesize that diminished peripheral PAG levels do not stem from reduced PAG synthesis but rather from limited PAG migration to the uterine stroma. Furthermore, our studies have indicated that PAGs induce significant alterations in target tissues, and the presence of High PAG phenotypes fosters an environment more favorable to the success of pregnancy
Digital Resource 15: BKAM, Full DALA (Database of African American and Predominantly White American Literature Anthologies) Corpus, Author Page Count, Identity as a percentage normalized, zoom
No full textPWAM, Full DALA Corpus, Author Page Count, Gender as a percentage normalized, zoom.Referenced in Chapter 4 of the book, "Digital Literary Redlining: African American Anthologies, Digital Humanities, and the Canon.
