Small extracellular vesicles derived from in vivo‐ or in vitro‐produced bovine blastocysts have different miRNAs profiles—Implications for embryo‐maternal recognition

Abstract

In vivo‐ and in vitro‐produced bovine embryos have different metabolic profiles and differences in gene transcription patterns. These embryos also have a distinct ability to establish and sustain early pregnancies. Small extracellular vesicles (sEVs) are secreted by embryos and carry bioactive molecules, such as miRNAs. We hypothesize that in vivo or in vitro‐produced bovine hatched blastocysts on Day 9 and the sEVs secreted by them have different miRNA profiles. To address this hypothesis, embryos of both groups were placed in in vitro culture on Day 7. After 48 h, hatched embryos and hatched embryo‐conditioned media (eCM) of both groups were collected. A total of 210 miRNAs were detected in embryos of both groups, of these 6 miRNAs were downregulated, while 7 miRNAs were upregulated in vitro group when compared to in vivo group. sEVs were isolated from eCM to determine miRNA profile. A total of 106 miRNAs were detected in both groups, including 14 miRNAs upregulated in sEVs from in vivo‐eCM, and 2 miRNAs upregulated in sEVs from in vitro‐eCM. These miRNAs express in embryos and sEVs secreted by them regulate early embryonic developmental and endometrial pathways, which can modify embryo‐maternal communication during early pregnancy and consequently affect pregnancy establishment.

Bovine in vitro oocyte maturation and embryo culture in liquid marbles 3D culture system

“…The same also occured with the drops during the IVM, however, as it was only 1 day in culture, we had a smaller loss of these microbioreactors, but during the 7 days culture this fragility in the system was more noticeable. The blastocyst rate obtained in control group corroborates with other studies [3,21], demonstrating that the performance of the technique was efficient. In addition to the lower blastocyst rate, the blastocysts subjected to the LM system presented a lower number of cells, another indication of the effect of this system on early embryo development [35].…”

Extracellular vesicles from oviductal and uterine fluids supplementation in sequential in vitro culture improves bovine embryo quality

“…However, the cross-talk between the embryo and uterine epithelium is quite intense also at early stages of development (D5-8 as in our model [86];), and EVs and miRNAs may probably participate in this communication. Interestingly, one of the upregulated miRNAs in UF-EVs was bta-miR-155, which was shown to be more expressed in IVD embryos between D7-9 of development compared with IVP [87]. This miRNA could be indicative of better quality of embryos as it may be transferred or induced by uterine EVs.…”

High body energy reserve influences extracellular vesicles miRNA contents within the ovarian follicle

“…The temperatures and times used were 95°C for 15 min followed by 45 cycles of 94°C for 15 seconds, 55°C for 30 seconds and 70°C for 30 seconds. For each sample (CC and FF EV) and group (MBER: n = 8; HBER: n = 4), the expression analysis of 383 bovine miRNAs was performed using the same forward sequences as published before [ 37 , 38 ]. The miRNAs were considered present when they presented a cycle threshold (CT) lower than 37 in all biological repetitions and an appropriate melting curve in more than 50% of samples; the miRNAs were considered exclusive when were expressed in all samples versus none samples.…”