221. SPRASA, a sperm protein with a post-fertilization function?

2005 ◽  
Vol 17 (9) ◽  
pp. 85
Author(s):  
A. Wagner ◽  
A. Shelling ◽  
L. Chamley
Keyword(s):  
Developmental Stages ◽  
Human Reproduction ◽  
Preimplantation Embryos ◽  
Sperm Protein ◽  
Treatment Groups ◽  
Bovine Sperm ◽  
Immune Mediated ◽  
Significant Difference ◽  
Integral Role

Objectives: SPRASA is a highly conserved sperm protein that is localised to the inner acrosome membrane, and shows high homology to the alpha-lactalbumin/C-type lysozyme family.1,2 We have previously shown that SPRASA is the antigen for antisperm antibodies in some infertile patients.1 To date, the function of SPRASA is unknown but in vitro, antibodies reactive with SPRASA inhibit sperm-oocyte binding in a zona-free hamster oocyte binding assay2. Based on this preliminary data, we postulated that SPRASA plays an integral role in fertilization, and that binding of antibodies to SPRASA may inhibit its function leading to infertility. In this study we investigated the effect of inhibiting bovine SPRASA, in vitro, on fertilization and embryonic development. Methods: Viable, motile sperm was prepared from frozen-thawed bovine sperm by swim up. Bovine oocytes were obtained from slaughter-house killed animals and matured in vitro. Three different treatments were investigated. (1) Sperm were incubated for an hour with a SPRASA-reactive antiserum, washed and used to fertilize 100 oocytes in insemination droplets. (2) One hundred in vitro matured oocytes were incubated for an hour with the SPRASA-reactive antiserum, washed, and fertilized with untreated swim-up sperm in insemination droplets. (3) Sperm and oocytes (n = 100) were coincubated with the SPRASA-reactive antiserum in insemination droplets. Controls consisted of similar numbers of sperm and/or oocytes incubated with an irrelevant antiserum. Results: There was a significant reduction in the number of embryos that reached morula (P = 0.03) or blastocyst (P=0.01) when oocytes were pre-treated with the SPRASA antiserum (treatment 2) or when sperm and oocytes were co-incubated with the antiserum (P=0.05 morula; P=0.01 blastocyst; treatment 3). However, there was no significant difference in the rates of embryos reaching earlier developmental stages in any of the treatment groups. Conclusion: These data suggest that SPRASA may be expressed by oocytes and/or preimplantation embryos. (1)Chiu WW, Erikson EK, Sole CA, Shelling AN, Chamley LW. (2004). SPRASA, a novel sperm protein involved in immune-mediated infertility. Human Reproduction 19(2), 243–249.(2)Mandal A, Klotz KL, Shetty J, Jayes FL, Wolkowicz MJ, Bolling LC, Coonrod SA, Black MB, Diekman AB, Haystead TA, Flickinger CJ, Herr JC. (2003). SLLP1, a unique, intra-acrosomal, non-bacteriolytic, c lysozyme-like protein of human spermatozoa. Biology of Reproduction 68(5), 1525–1537.

180 IDENTIFICATION AND QUANTIFICATION OF DIFFERENTIALLY REPRESENTED TRANSCRIPTS IN PREIMPLANTATION BOVINE EMBRYOS

2008 ◽  
Vol 20 (1) ◽  
pp. 169 ◽  
Author(s):  
C. E. McHughes ◽  
G. K. Springer ◽  
L. D. Spate ◽  
R. Li ◽  
R. J. Woods ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Nuclear Transfer ◽  
Developmental Stages ◽  
Reproductive Technologies ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Cell Stage ◽  
Production Techniques

Identification of transcripts that are present at key development stages of preimplantation embryos is critical for a better understanding of early embryogenesis. To that end, this project had two goals. The first was to characterize the relative abundance of multiple transcripts during several developmental stages, including metaphase II-stage oocytes (MPII), and 2-cell-stage (2-cell), precompact morula (PCM), and in vitro-produced blastocyst-stage (IVTBL) embryos. The second was to characterize differences in the relative abundance of transcripts present in in vivo- (IVVBL), in vitro-, and nuclear transfer-produced (NTBL) blastocysts. It was our hypothesis that the identification of differentially represented transcripts from these stages would reveal not only developmentally important genes, but also genes that might be aberrantly expressed due to embryo production techniques. Individual clusters from a large bovine EST project (http://genome.rnet.missouri.edu/Bovine/), which focused on female reproductive tissues and embryos, were compared using Fisher's exact test weighted by number of transcripts per tissue by gene (SAS PROC FREQ; SAS Institute, Inc., Cary, NC, USA). Of the 3144 transcripts that were present during embryogenesis, 125 were found to be differentially represented (P < 0.01) in at least one pairwise comparison (Table 1). Some transcripts found to increase in representation from the MPII to the 2-cell stage include protein kinases, PRKACA and CKS1, as well as the metabolism-related gene, PTTG1. These same transcripts were also found to decrease in representation from the 2-cell to the PCM stage. RPL15 (translation) and FTH1 (immune function) were both more highly represented in the PCM than in the 2-cell stage. From PCM to IVTBL, we saw an increase in RPS11, another translation-related transcript. When comparing blastocyst-stage embryos from different production techniques, several transcripts involved in energy production (e.g., COX7B and COX8A) were found to be more highly represented in the NTBL than in the IVTBL. COX8A was also more highly represented in the IVVBL than in the IVTBL. By investigating these differentially represented transcripts, we will be able to better understand the developmental implications of embryo manipulation. We may also be able to better develop reproductive technologies that lead to in vitro- and nuclear transfer-derived embryos which more closely follow a normal program of development. Table 1. Differentially represented transcripts between developmental stages

233. Oxygen concentration during in vitro maturation of murine oocytes affects blastocyst cell lineage

2005 ◽  
Vol 17 (9) ◽  
pp. 91
Author(s):  
K. M. Banwell ◽  
M. Lane ◽  
D. L. Russell ◽  
K. L. Kind ◽  
J. G. Thompson
Keyword(s):  
Embryo Development ◽  
In Vitro Maturation ◽  
Cell Lineage ◽  
Developmental Competence ◽  
Embryo Viability ◽  
Blastocyst Development ◽  
Treatment Groups ◽  
Significant Difference ◽  
O2 Concentration

Follicular antral oxygen tension is thought to influence subsequent oocyte developmental competence. Despite this, in vitro maturation (IVM) is routinely performed in either 5 or 20% O2 and while low O2 has been shown to be beneficial to embryo development in many species, the effect of altering O2 concentration during IVM has not been adequately investigated. Here we investigated the effects of a range of O2 concentrations during IVM on meiotic maturation and subsequent embryo development after IVF. Ovaries from eCG-stimulated CBA F1 female mice (21 days) were collected and intact cumulus oocyte complexes (COCs) cultured for 17–18 h under 2, 5, 10 or 20% O2 (6% CO2 and balance of N2). Matured COCs were denuded of cumulus cells, fixed and stained (1% aceto-orcein) for visualisation of maturation status. No significant difference in maturation rates between treatment groups was observed. Following IVF (performed under 5% O2, 6% CO2 and balance of N2), no difference in fertilisation rates between treatment groups was observed in a randomly selected cohort 7 h post-fertilisation. There was also no significant difference in cleavage rates after 24 h or ability to reach blastocyst stage after 96 h, with a tendency (P = 0.079) for more blastocysts in 2% O2. However there was a significant increase in the number of trophectoderm cells present in the resulting blastocysts (P < 0.05) in the 2% O2 group (35 ± 2.1) compared to 20% O2 (25 ± 2.8). Our data suggests that O2 concentration during IVM does not influence nuclear maturation or subsequent fertilisation, cleavage and blastocyst development rates. However, maturation in 2% O2 significantly alters subsequent cell lineage within blastocysts to favour trophectoderm development. Such skewed trophectoderm cell number may influence embryo viability. Funded by NHMRC and NIH.

Assessment of binder of sperm protein 1 (BSP1) and heparin effects on in vitro capacitation and fertilization of bovine ejaculated and epididymal sperm

Zygote ◽  
2020 ◽  
Vol 28 (6) ◽  
pp. 489-494
Author(s):  
Paula Rodríguez-Villamil ◽  
Daiane Mentz ◽  
Felipe Ledur Ongaratto ◽  
Luis Henrique Aguiar ◽  
Jose Luiz Rodrigues ◽  
...  
Keyword(s):  
Control Group ◽  
Sperm Capacitation ◽  
Epididymal Sperm ◽  
Sperm Protein ◽  
Fertilization Rates ◽  
Bovine Sperm ◽  
Development Rates ◽  
Developmental Rates

SummaryThe present study evaluated the effect of binder of sperm protein 1 (BSP1) and/or heparin on in vitro bovine capacitation and fertilization rates using epididymal and ejaculated bovine sperm. Frozen–thawed sperm were selected and used in the following treatments. Control group: Fert-TALP medium without heparin; heparin (HEP) group: Fert-TALP with heparin (10 UI/ml); BSP1 group: Fert-TALP medium with BSP1 (10 µg/ml for ejaculated sperm; 40 µg/ml for epididymal sperm); HEP + BSP1 group: Fert-TALP medium with heparin (5 UI/ml) and BSP1 (5 µg/ml for ejaculated sperm; 20 µg/ml for epididymal sperm) and determined in vitro capacitation rates in different interval times (0, 15, 30 and 60 min) using the chlortetracycline fluorescence (CTC) method. Also, we evaluated the development rates of oocytes fertilized with ejaculated or epididymal sperm into the same treatments. Capacitation was greater and faster when ejaculated sperm were treated for 60 min with heparin compared with other treatments. However, developmental rates were similar in all treatments. For epididymal sperm, the treatments with BSP1 presented higher capacitation and fertilization rates compared with heparin (P < 0.05). The effects of heparin + BSP1 on capacitation and developmental rates did not cause any increase in capacitation or blastocyst rates compared with other groups for ejaculated or epididymal sperm. In conclusion, this study confirmed that either BSP1 and heparin can be used as capacitator agents for bovine ejaculated sperm during IVF. However, BSP1 seems to be more efficient compared with heparin for epididymal sperm. Furthermore, BSP1 and heparin have no synergic effects on sperm capacitation.

Expression of mRNA encoding leukaemia inhibitory factor (LIF) and its receptor (LIFRβ) in buffalo preimplantation embryos produced in vitro: markers of successful embryo implantation

Zygote ◽  
2012 ◽  
Vol 21 (2) ◽  
pp. 203-213 ◽  
Author(s):  
S. Eswari ◽  
G. Sai Kumar ◽  
G. Taru Sharma
Keyword(s):  
Culture Media ◽  
Total Cell ◽  
Inhibitory Factor ◽  
Preimplantation Embryos ◽  
Leukaemia Inhibitory Factor ◽  
Hatching Rate ◽  
Blastocyst Development ◽  
Cell Stage ◽  
Significant Difference

SummaryThe objective of this study was to evaluate the effect of supplementation of recombinant leukaemia inhibitory factor (LIF) in culture media on blastocyst development, total cell number and blastocyst hatching rates and the reverse transcription-polymerase chain reaction analysis of preimplantation buffalo embryos to determine whether they contain the LIF-encoding mRNA and its beta receptor (LIFRβ) genes in different stages of preimplantation buffalo embryos. Cumulus–oocyte complexes retrieved from slaughterhouse buffalo ovaries were matured in vitro and fertilized using frozen buffalo semen. After 18 h of co-incubation with sperm, the presumptive zygotes were cultured in modified synthetic oviductal fluid without (control) or with rhLIF (100 ng/ml). There was no significant difference in the overall cleavage rate up to morula stage however the development of blastocysts, hatching rate and total cell numbers were significantly higher in the LIF-treated group than control. Transcripts for LIFRβ were detected from immature, in vitro-matured oocytes and in the embryos up to blastocyst stage, while transcripts for the LIF were detected from 8–16-cell stage up to blastocyst, which indicated that embryo-derived LIF can act in an autocrine manner on differentiation process and blastocyst formation. This study indicated that the addition of LIF to the embryo culture medium improved development of blastocysts, functional (hatching) and morphological (number of cells) quality of the blastocysts produced in vitro. The stage-specific expression pattern of LIF and LIFRβ mRNA transcripts in buffalo embryos indicated that LIF might play an important role in the preimplantation development and subsequent implantation of buffalo embryos.

scholarly journals Combination Therapy in Treatment of Experimental Pulmonary Aspergillosis: In Vitro and In Vivo Correlations of the Concentration- and Dose- Dependent Interactions between Anidulafungin and Voriconazole by Bliss Independence Drug Interaction Analysis

2009 ◽  
Vol 53 (6) ◽  
pp. 2382-2391 ◽  
Author(s):  
Vidmantas Petraitis ◽  
Ruta Petraitiene ◽  
William W. Hope ◽  
Joseph Meletiadis ◽  
Diana Mickiene ◽  
...  
Keyword(s):  
Drug Interaction ◽  
Interaction Analysis ◽  
Invasive Pulmonary Aspergillosis ◽  
Pulmonary Aspergillosis ◽  
Treatment Groups ◽  
Synergistic Interactions ◽  
Significant Difference ◽  
Bliss Independence

ABSTRACT We studied the antifungal activity of anidulafungin (AFG) in combination with voriconazole (VRC) against experimental invasive pulmonary aspergillosis (IPA) in persistently neutropenic rabbits and further explored the in vitro and in vivo correlations by using Bliss independence drug interaction analysis. Treatment groups consisted of those receiving AFG at 5 (AFG5 group) and 10 (AFG10 group) mg/kg of body weight/day, VRC at 10 mg/kg every 8 h (VRC group), AFG5 plus VRC (AFG5+VRC group), and AFG10 plus VRC (AFG10+VRC group) and untreated controls. Survival throughout the study was 60% for the AFG5+VRC group, 50% for the VRC group, 27% for the AFG10+VRC group, 22% for the AFG5 group, 18% for the AFG10 group, and 0% for control rabbits (P < 0.001). There was a significant reduction of organism-mediated pulmonary injury, measured by infarct scores, lung weights, residual fungal burdens, and galactomannan indexes, in AFG5+VRC-treated rabbits versus those treated with AFG5 and VRC alone (P < 0.05). In comparison, AFG10+VRC significantly lowered only infarct scores and lung weights in comparison to those of AFG10-treated animals (P < 0.05). AFG10+VRC showed no significant difference in other outcome variables. Significant Bliss synergy was found in vivo between AFG5 and VRC, with observed effects being 24 to 30% higher than expected levels if the drugs were acting independently. These synergistic interactions were also found between AFG and VRC in vitro. However, for AFG10+VRC, only independence and antagonism were observed among the outcome variables. We concluded that the combination of AFG with VRC in treatment of experimental IPA in persistently neutropenic rabbits was independent to synergistic at a dosage of 5 mg/kg/day but independent to antagonistic at 10 mg/kg/day, as assessed by Bliss independence analysis, suggesting that higher dosages of an echinocandin may be deleterious to the combination.

Effects of the addition of glutathione during maturation on in vitro fertilisation of prepubertal goat oocytes

Zygote ◽  
2001 ◽  
Vol 9 (4) ◽  
pp. 323-330 ◽  
Author(s):  
P. Mayor ◽  
M. López-Béjar ◽  
E. Rodríguez-González ◽  
M.T. Paramio
Keyword(s):  
Preimplantation Embryos ◽  
In Vitro Fertilisation ◽  
Treatment Groups ◽  
Fertilisation Rate ◽  
Maturation Medium ◽  
Nuclear Stage ◽  
17Β Estradiol ◽  
Bovine Fetal Serum ◽  
Fresh Semen

Glutathione (γ-glutamyl-cysteinyl-glycine; GSH) is a ubiquitous intracellular free thiol that improves development of the male pronucleus at fertilisation and has also been implicated in promoting the development of preimplantation embryos. The objective of this study was to evaluate the effects of adding GSH or cysteine to the in vitro maturation medium on intracellular GSH amounts after in vitro maturation and fertilisation of prepubertal goat oocytes. Oocytes were matured in TCM199 medium supplemented with 10% bovine fetal serum, 1 mg/ml 17β-estradiol, 10 μg/ml o-FSH, 10 μg/ml LH and 50 mg/ml gentamicin. In vitro maturation medium was completed with two independent treatments: GSH at different concentrations (0, 0.25, 0.50 and 1.00 mM) and L-cysteine at different concentrations (0, 150, 300, 600 and 900 μM). After 27 h of culture at 38.5 °C in 5% CO2 in air, the nuclear stage was evaluated. Simultaneously, another sample of oocytes was frozen and the intracellular GSH level was evaluated with spectrophotometric methodology. Oocytes were inseminated with fresh semen (2-3 × 106 sperm/ml) in TALP medium supplemented with 1 mg/ml hypotaurine. Oocytes were fixed at 20 h post-insemination to evaluate the in vitro fertilisation. Oocytes matured in 1.00 mM GSH-supplemented medium exhibited higher amounts of intracellular GSH (3.23 pmol per oocyte). The percentage of normal fertilisation (17-27%) was similar for the treatment groups. In conclusion, the addition of 1.00 mM GSH to the maturation medium could be a useful method for increasing the intracellular GSH levels of prepubertal goat oocytes. However, this increase was not associated with a higher normal fertilisation rate of prepubertal goat oocytes.

scholarly journals Beneficial Effects of Neurotrophin-4 Supplementation During in vitro Maturation of Porcine Cumulus-Oocyte Complexes and Subsequent Embryonic Development After Parthenogenetic Activation

2021 ◽  
Vol 8 ◽  
Author(s):  
Mirae Kim ◽  
Seon-Ung Hwang ◽  
Junchul David Yoon ◽  
Joohyeong Lee ◽  
Eunhye Kim ◽  
...  
Keyword(s):  
Treatment Group ◽  
Signaling Pathway ◽  
Oocyte Maturation ◽  
Follicular Development ◽  
Developmental Competence ◽  
Treatment Groups ◽  
Beneficial Effects ◽  
Significant Difference ◽  
Egf Signaling

Neurotrophin-4 (NT-4) is a neurotrophic factor that plays an important role in follicular development and oocyte maturation. However, it is not yet known whether NT-4 is related to oocyte maturation and follicular development in pigs. This study aims to investigate the effects of NT-4 supplementation during in vitro maturation (IVM) of porcine oocytes and subsequent embryonic development after parthenogenetic activation (PA). First, NT-4 and its receptors (TrkB and p75NTR) were identified through fluorescent immunohistochemistry in porcine ovaries. NT-4 was mainly expressed in theca and granulosa cells; phospho-TrkB and total TrkB were expressed in theca cells, granulosa cells, and oocytes; p75NTR was expressed in all follicular cells. During IVM, the defined maturation medium was supplemented with various concentrations of NT-4 (0, 1, 10, and 100 ng/mL). After IVM, the nuclear maturation rate was significantly higher in the 10 and 100 ng/mL NT-4 treated groups than in the control. There was no significant difference in the intracellular reactive oxygen species levels in any group after IVM, but the 1 and 10 ng/mL NT-4 treatment groups showed a significant increase in the intracellular glutathione levels compared to the control. In matured cumulus cells, the 10 ng/mL NT-4 treatment group showed significantly increased cumulus expansion-related genes and epidermal growth factor (EGF) signaling pathway-related genes. In matured oocytes, the 10 ng/mL treatment group showed significantly increased expression of cell proliferation-related genes, antioxidant-related genes, and EGF signaling pathway-related genes. We also investigated the subsequent embryonic developmental competence of PA embryos. After PA, the cleavage rates significantly increased in the 10 and 100 ng/mL NT-4 treatment groups. Although there was no significant difference in the total cell number of blastocysts, only the 10 ng/mL NT-4 treatment group showed a higher blastocyst formation rate than the control group. Our findings suggest that supplementation with the 10 ng/mL NT-4 can enhance porcine oocyte maturation by interacting with the EGF receptor signaling pathway. In addition, we demonstrated for the first time that NT-4 is not only required for porcine follicular development, but also has beneficial effects on oocyte maturation and developmental competence of PA embryos.

scholarly journals Embryo Development of Cypripedium formosanum in Relation to Seed Germination In Vitro

2005 ◽  
Vol 130 (5) ◽  
pp. 747-753 ◽  
Author(s):  
Yung-I Lee ◽  
Nean Lee ◽  
Edward C. Yeung ◽  
Mei-Chu Chung
Keyword(s):  
Seed Germination ◽  
Embryo Development ◽  
Developmental Stages ◽  
Culture Media ◽  
Nile Red ◽  
Germination Percentage ◽  
Zygotic Embryogenesis ◽  
Seed Collection ◽  
Significant Difference

This investigation documents the key anatomical features in embryo development of Cypripedium formosanum Hayata, in association with the ability of embryos to germinate in vitro, and examines the effects of culture media and seed pretreatments on seed germination. A better understanding of zygotic embryogenesis for the Cypripedium L. species would provide insights into subsequent germination events and aid in the in vitro propagation of these endangered species. In seeds collected at 60 days after pollination (DAP), soon after fertilization, no germination was recorded. The best overall germination was found at 90 DAP (≈70%), at which time early globular to globular embryos with a single-celled suspensors can be observed. After 135 DAP, the seeds germinated poorly. At this time the inner integument shrinks and forms a tight layer, which encloses the embryo, the so-called “carapace.” Using Nile red stain, a cuticular substance was detected in the carapace, which may play a role in the impermeability of the mature seed and may help the seeds survive in the stringent environment. At maturity (after 210 DAP), the embryo proper has an average size of eight cells along its length and six cells across the width. Lipids and proteins are the main storage products within the embryo. To improve seed germination, experiments were conducted to test the suitability of various media and pretreatments of seeds. When different media were used, except for the Harvais medium at 120 DAP, there was no significant difference in seed germination at three different developmental stages tested. Soaking mature seeds in 1% NaOCl or treating them with ultrasound may slightly increase the germination percentage. For seed germination, our results indicate that the timing of seed collection outweighs the composition of medium and the seed pretreatments.

scholarly journals Effect of resveratrol on the in vitro maturation of ovine (Ovis aries) oocytes and the subsequent development of handmade cloned embryos

2019 ◽  
Vol 5 (4) ◽  
Author(s):  
José Luis Martínez-Ibarra ◽  
Eugenia Adriana Espinoza-Mendoza ◽  
Raymundo Rangel-Santos ◽  
Demetrio Alonso Ambriz-García ◽  
María Del Carmen Navarro-Maldonado
Keyword(s):  
Embryo Quality ◽  
Developmental Stages ◽  
Subsequent Development ◽  
Poor Quality ◽  
Ovis Aries ◽  
Control Group ◽  
Nuclear Maturation ◽  
Significant Difference ◽  
Maturation Rate

The effect of resveratrol on the in vitro maturation (IVM) of ovine (Ovis aries) oocytes and the development of handmade cloned embryos was evaluated. The nuclear maturation and reactive oxygen species (ROS) levels in the oocytes, as well as the early development and morphological cloned embryo quality, were evaluated under different resveratrol concentrations (0, 0.5, 2 and 5 μM). After IVM, no significant difference was observed in the maturation rate of oocytes treated with 0.5 μM (81.3 %) and 2 μM (72 %) resveratrol compared to that of the control group (0 μM) (74.2 %), but the rate significantly decreased at 5 μM (56 %) (p < 0.05). When the oocyte ROS levels were determined, no significant differences among the groups were observed (p > 0.05). For cloned embryo development, the embryos obtained from the oocytes treated with 0.5 μM resveratrol showed higher (p < 0.05) compacted morula rates (10.7 %) compared to the embryos obtained from the oocytes treated with 0, 2 and 5 μM (6.2, 0 and 0 %, respectively). Regarding embryo morphological quality, the embryos from the oocytes treated with 0.5 μM resveratrol showed a lower rate of poor quality morulae (4.7 %) in comparison to those treated with 0, 2 and 5 μM (23.8, 23.3 and 33.3 %, respectively) (p < 0.05). In conclusion, resveratrol showed no significant improvement on the IVM or ROS levels in domestic ovine oocytes. However, treatment with 0.5 μM resveratrol during IVM improved embryo quality and promoted morulae compaction of Ovis aries handmade cloned embryos.Figure 3. Different developmental stages of the HMC sheep embryos cultured in the WOW system. Cleaved embryos (a-d), 8‒16 blastomere embryos (e-h), morulae (i-l) and compact morulae (m-p) (200X).

139 BOVINE PREIMPLANTATION EMBRYOS SECRETE EXTRACELLULAR VESICLES, WHICH MAY INDICATE EMBRYO COMPETENCE

2017 ◽  
Vol 29 (1) ◽  
pp. 178
Author(s):  
E. Mellisho ◽  
A. Velasquez ◽  
M. J. Nuñez ◽  
L. Rodriguez-Alvarez
Keyword(s):  
Extracellular Vesicles ◽  
Culture Media ◽  
Total Cell ◽  
Developmental Competence ◽  
Preimplantation Embryos ◽  
Lower Amount ◽  
Bovine Embryos ◽  
Significant Difference ◽  
Blastulation Rate

Pre-implantation embryos secrete extracellular vesicles (EV) most likely to communicate with the surroundings. The objective of this study was to determine the distribution (size and concentration) of EV secreted by bovine pre-implantation embryos with different developmental competence. The IVF bovine embryos were produced from oocytes recovered from slaughterhouse ovaries. Presumptive zygotes were in vitro cultured (IVC) in groups in 4-well plates (30 zygotes per 500-µL well) using SOFaa medium at 39°C under 5% CO2, 5% O2, and 90% N2 until the morula stage (Day 5 post IVF). Morulae were cultured individually in 96 well at 39°C under until blastulation time (Day 6.5–7.5) in EV-free SOF medium. Culture medium was collected only from embryos that developed to the blastocyst stage that were classified in a group of early (Day 6.5) or late (Day 7.5) blastulation. Blastocysts were kept in culture until Day 11 to assess embryo developmental competence, considering embryo size (>350 µm) and total cell count (>500 blastomeres). For EV analysis, 4 groups were organised a posteriori: G1: Day 6.5-competent; G2: Day 6.5-not competent; G3: Day 7.5-competent; G4: Day 7.5-not competent. The EV in culture media were analysed using a nanoparticle tracking analysis (Nanosight NS300). Statistical analysis was performed using the InfoStat program (Buenos Aires, Argentina). Differences were considered significant at P < 0.05. Early blastulation rate (Day 6.5) was 40.3% (112/278), whereas late blastulation rate (Day 7.5) was 20.5% (57/278), showing a significant difference (P < 0.0001). Embryos derived from Day 6.5 blastocysts have a higher probability (39.3%: 44/112) of posthatching development [until Day 11; Day 7.5, 10.5% (6/57); P = 0.0001]. At Day 11, competent embryos (G1) derived from Day 6.5 blastocysts have a higher diameter and total cell number (447 µm; 688 cells) than those derived from Day 7.5 blastocysts (G3; 405 µm, 598 cells; P < 0.05 for both parameters). It was possible to detect EV from collected medium of individual embryos independent of their competence. Neither the EV size nor the EV concentration was statistically different between Day 6.5 and Day 7.5 blastocysts (without considering their further competence; 2.9 × 108, 147 nm; and 3.0 × 108, 149 nm, respectively). However, independent of the day of blastulation, competent embryos had a significantly lower concentration of EV (2.7 × 108 v. 3.3 × 108; P = 0.03). Moreover, competent embryos from early and late blastocysts (G1 and G3) tend to produce a lower amount of EV (G1: 2.8 × 108; G2: 3 × 108; G3: 2.6 × 108; G4: 3.5 × 108; P = 0.05). Furthermore, EV concentration was statistically different between G3 and G4 (P = 0.002). No differences in EV size were observed among groups (G1: 145 nm; G2: 148 nm; G3: 146 nm; G4: 151 nm). Our results provide an initial approach to study the EV secreted by individual pre-implantation embryos to assess their competence. From these results, we can conclude that blastulation time affects the future development of bovine embryos and a model based on blastulation time and EV secretion could be a simple noninvasive tool to improve embryo selection.

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