scholarly journals Oocyte Selection for In Vitro Embryo Production in Bovine Species: Noninvasive Approaches for New Challenges of Oocyte Competence

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2196
Author(s):  
Luis Aguila ◽  
Favian Treulen ◽  
Jacinthe Therrien ◽  
Ricardo Felmer ◽  
Martha Valdivia ◽  
...  

The efficiency of producing embryos using in vitro technologies in livestock species rarely exceeds the 30–40% threshold, indicating that the proportion of oocytes that fail to develop after in vitro fertilization and culture is considerably large. Considering that the intrinsic quality of the oocyte is one of the main factors affecting blastocyst yield, the precise identification of noninvasive cellular or molecular markers that predict oocyte competence is of major interest to research and practical applications. The aim of this review was to explore the current literature on different noninvasive markers associated with oocyte quality in the bovine model. Apart from some controversial findings, the presence of cycle-related structures in ovaries, a follicle size between 6 and 10 mm, large number of surrounding cumulus cells, slightly expanded investment without dark areas, large oocyte diameter (>120 microns), dark cytoplasm, and the presence of a round and smooth first polar body have been associated with better competence. In addition, the combination of oocyte and zygote selection via brilliant cresyl blue (BCB) test, spindle imaging, and the anti-Stokes Raman scattering microscopy together with studies decoding molecular cues in oocyte maturation have the potential to further optimize the identification of oocytes with better developmental competence for in-vitro-derived technologies in livestock species.

Author(s):  
Luis Aguila ◽  
Favian Treulen ◽  
Jacinthe Therrien ◽  
Ricardo Felmer ◽  
Martha Valdivia ◽  
...  

The efficiency of producing embryos using in vitro technologies in livestock species rarely exceeds the 30 to 40% threshold, indicating that the proportion of oocytes that fail to develop after in vitro fertilization and culture is considerably large. Considering that the intrinsic quality of the oocyte is one of the main factors affecting blastocyst yield, the precise identification of non-invasive cellular or molecular markers that predict oocyte competence is of major interest to research and practical applications. The aim of this review was to explore the current literature on different non-invasive markers associated with oocyte quality in mammalian species, with an emphasis on the bovine model. Apart from some controversial findings, the presence of cycle-related structures in ovaries, a follicle size between 6 and 10 mm, large number of surrounding cumulus cells, slightly expanded investment without dark areas, large oocyte diameter (>120 microns), dark cytoplasm, and the presence of a round and smooth first polar body have been associated to better competence. In addition, the combination of oocyte and zygote selection by BCB test and spindle imaging have the potential to further optimize the identification of oocytes with better developmental competence for in vitro-derived technologies in livestock species.


Author(s):  
Luis Aguila ◽  
Favian Treulen ◽  
Jacinthe Therrien ◽  
Ricardo Felmer ◽  
Martha Valdivia ◽  
...  

The efficiency of producing embryos using in vitro technologies in livestock species rarely exceeds the 30 to 40% threshold, indicating that the proportion of oocytes that fail to develop after in vitro fertilization and culture is considerably large. Considering that the intrinsic quality of the oocyte is one of the main factors affecting blastocyst yield, the precise identification of non-invasive cellular or molecular markers that predict oocyte competence is of major interest to research and practical applications. The aim of this review was to explore the current literature on different non-invasive markers associated with oocyte quality in the bovine model. Apart from some controversial findings, the presence of cycle-related structures in ovaries, a follicle size between 6 and 10 mm, large number of surrounding cumulus cells, slightly expanded investment without dark areas, large oocyte diameter (>120 microns), dark cytoplasm, and the presence of a round and smooth first polar body have been associated to better competence. In addition, the combination of oocyte and zygote selection by BCB test and spindle imaging have the potential to further optimize the identification of oocytes with better developmental competence for in vitro-derived technologies in livestock species.


2014 ◽  
Vol 26 (1) ◽  
pp. 192
Author(s):  
L. Cai ◽  
E. Kim ◽  
S. U. Hwang ◽  
J. D. Yoon ◽  
Y. Jeon ◽  
...  

Evaluation of morphology of first polar body (1st PB) could be a method for the oocyte's quality and developmental competence. The developmental potential of oocyte with fragmented PB after in vitro maturation (IVM) is a controversial issue. The aim of this study is to investigate the effects of PB morphology type on oocyte quality and developmental competence after IVF. Porcine ovaries were obtained from prepubertal gilts at a local slaughterhouse and transported to the laboratory within 2 h in physiological saline supplemented with 100 IU mL–1 penicillin G and 100 mg mL–1 streptomycin sulfate. The cumulus–oocyte complexes (COC) were aspirated using an 18-gauge needle attached to a 10-mL disposable syringe from superficial follicles 3 to 6 mm in diameter followed by IVM. After IVM, oocytes were classified into 3 types as follows, oocytes with normal PB (A type), oocytes with a little of fragmented PB (B type), and oocytes with separated 2 PBs (C type), respectively. As classification of PB types, we analysed the distribution ratio of each PB type after IVM, and then performed IVF for analysis of fertilization rate and developmental potential. The ratio of oocyte with A type (73%) was significantly (P < 0.05) higher than that of B type (24.5%) or C type (2.5%) after IVM. Only mature oocytes were selected from A and B type and were subjected to IVF because of a small number of oocytes with C type. In the IVF experiment, the efficiency of monospermy and fertilization were significantly higher in oocytes of A type (46.7%) than those of type B (20.0%). The cleavage rate of oocytes with A type (63.9%) was significantly (P < 0.05) higher than the oocytes with B type (43.8%). Embryonic developmental competence to the blastocyst stage after IVF was significantly (P < 0.05) higher in the A-type oocytes (26.3%) than in the B-type oocytes (16.9%). The levels of glutathione and reactive oxygen species were not affected by the morphological classification of the PB. In summary, these results suggest that polar body morphology could be a marker of oocyte quality after IVM. We are currently studying gene expression of each oocytes and blastocysts. This work was supported, in part, by a grant from the Next-Generation BioGreen 21 Program (No. PJ00956901), Rural Development Administration, and the National Research Foundation of Korea Grant funded by the Korean Government (NRF-2012R1A1A4A01004885, NRF-2013R1A2A2A04008751), Republic of Korea.


2010 ◽  
Vol 22 (1) ◽  
pp. 210 ◽  
Author(s):  
A. R. Moawad ◽  
J. Zhu ◽  
I. Choi ◽  
K. H. S. Campbell

Oocyte cryopreservation is a potentially valuable way of preserving female germ cells. However, to date the reported developmental competence of cryopreserved oocytes is low. The objectives of this study were to investigate the effects of demecolcine pretreatment on viability, timing of the first polar body extrusion (PBI), spindle, chromatin organization, and in vitro embryo development of ovine vitrified germinal vesicle (GV) oocytes after in vitro fertilization (IVF) and parthenogenetic activation. Cumulus-oocyte complexes (COC) aspirated from ovine ovaries collected at slaughter were selected and randomly divided into 3 groups: (1) untreated (in vitro matured, IVM) as a control, (2) vitrified (Moawad AR et al. 2009 Reprod. Fertil. Dev. 21, 135 abst), and (3) deme + vitrified (oocytes were incubated with 0.1 μg mL-1 demecolcine for 20 min before vitrification). After vitrification COC were thawed and matured in vitro for 24 h. Following IVM, oocytes from 3 groups were subsequently subjected to (1) immunostaining, (2) IVF, or (3) activation. Presumptive zygotes were cultured in vitro in SOF media for 7 days. Data were analyzed using chisquare and t-test. No significant differences (P > 0.05) were observed in survival rates between deme + vitrified (90.8%, 324/357) and vitrified (87.2%, 211/242). However, the numbers of oocytes with PBI in two vitrified groups at 18 h (20.4 and 8.5 v. 47.1%) and 24 h post IVM (51 and 43.2 v. 88.5%) were significantly lower (P < 0.01) than those in the control. Percentage of normal spindle and chromatin configuration in the two vitrified groups also significantly decreased (P < 0.05) compared with those in the control (42.5 and 41.8 v. 76.5%), whereas missing spindle in the 2 vitrified groups significantly increased (P < 0.001) compared with the controls (47.5 and 32.7 v. 3.9%). Following IVF (pi), cleavage rates at 24.48 hpi and morula development (5 days pi) were significantly lower (P < 0.001) in deme + vitrified (6.1, 43.1, and 28.5%) and vitrified groups (3.3, 30.1, and 22.9%) than control (50.4, 82.4, and 46.4%). Blastocyst development in deme + vitrified (9.8%) and control (33.6%) was significantly higher (P < 0.01) than in vitrified group (1.3%). Hatched blastocysts were observed only in deme + vitrified and control groups (4.9 v. 12.8%). In addition, post activation (pa) cleavage rates in deme + vitrified (10.3 v. 40.7%) and control (52.5 v. 76.7%) at 24 and 48 hpa were significantly higher (P < 0.05) than those in the vitrified group. Blastocyst development in deme + vitrified (4.8%) was higher than that in the vitrified group (1.8%), but not significant (P > 0.05); however, these values were still significantly lower (P < 0.001) than those in the control (24.2%). No significant differences were observed in total cell numbers per blastocyst between all the groups. Taken together, these results suggest that pretreatment of oocytes with demecolcine before vitrification could improve the developmental competence of ovine vitrified-thawed GV-stage oocytes. A. R. Moawad was supported by the Egyptian government.


2008 ◽  
Vol 20 (1) ◽  
pp. 164
Author(s):  
D. K. Berg ◽  
S. E. Beaumont ◽  
P. L. Pfeffer

MicroRNAs (miRNAs) are a class of naturally occurring non-coding RNAs that play a role in gene regulation. They are highly conserved, single-stranded RNAs, 22 nucleotides in length, that are cleaved from larger inactive hairpin precursor transcripts, and use the RNA interference-related pathways to repress their mRNA targets. They play diverse regulatory roles in cellular proliferation, morphogenesis, apoptosis, and differentiation. Maternal miRNAs are crucial for early mammalian development (Murchison et al. 2007 Genes Dev. 21, 682–693; Tang et al. 2007 Genes Dev. 21, 655–648), while sperm-borne miRNAs do not contribute significantly to miRNAs in the zygote (Amanai et al. 2006 Biol. Reprod. 75, 877–884). Our objective was to identify miRNAs that are expressed during bovine in vitro oocyte maturation (MII) and blastocyst stages as well as during parthenogenic development. MII oocytes (n = 1680) were generated from abattoir-derived oocytes and matured in vitro for 24 h. Cumulus cells were removed and the first polar body was visually assessed before the oocytes were frozen in liquid N2. Parthenogenic blastocysts (n = 575) were produced using ionomycin/6DMAP activation, and IVF blastocysts (n = 1150) were produced using standard in vitro fertilization followed by in vitro culture in synthetic oviduct fluid (Thompson et al. 2000 J. Reprod. Fertil. 118, 47–55). Blastocysts (grades 1 and 2) were selected on Day 7 post-activation/insemination and frozen in liquid N2. RNA was isolated using the mirVana miRNA isolation kit (Ambion, Scoresby, Victoria, Australia). miRNAs were quantified using the TaqMan� MicroRNA Human Panel-Early Access Kit (Applied Biosystems, Scoresby, Victoria, Australia) following the manufacturer's protocol. Absolute copy numbers per embryo were estimated. Of the 157 miRNAs in the panel, 102, 136, and 118 were detected above background in oocytes, IVF, and parthenogenic blastocysts, respectively. Only 28 miRNAs were present at over 100 copies in MII oocytes, with maximum levels reaching 1300 copies. Levels were generally much higher at blastocyst stages, with 21 miRNAs present at more than 10 000 copies. miR-16 was one of the most abundant miRNAs in all samples tested. Copy numbers per blastomere cell were 5-fold higher in IVF blastocysts compared to parthegenotic blastocysts for miR-19a, 21, and 30b. The low copy numbers of mature miRNAs before embryonic genome activation may have implications for somatic cell nuclear transfer experiments in that exogenously added miRNAs from the donor cell could impact on the embryonic gene expression profiles.


2014 ◽  
Vol 26 (1) ◽  
pp. 136
Author(s):  
T. Somfai ◽  
K. Kikuchi ◽  
K. Yoshioka ◽  
F. Tanihara ◽  
H. Kaneko ◽  
...  

Development to term of vitrified porcine follicular oocytes is reported in the present study. Immature cumulus-oocyte complexes (COC) were collected from slaughtered prepubertal gilts and were vitrified according to our method published recently (Somfai et al. 2013 J. Reprod. Dev., in press). Briefly, after pretreatment with 7.5 μg mL–1 of cytochalasin B (CB) for 30 min in modified NCSU-37 (a basic medium, BM) at 38.5°C, groups of 88 to 121 COC were equilibrated in a mixture of 2% ethylene glycol (EG), 2% propylene glycol (PG), and 7.5 μg mL–1 CB for 13 to 15 min. Then, COC were washed in vitrification solution (17.5% EG, 17.5% PG, 5% polyvinyl pyrrolidone, and 0.3 M trehalose in BM) and then dropped with 2 μL of vitrification solution onto the surface of aluminum foil floating on liquid nitrogen (LN2). Microdroplets (each containing 10–25 COC) were transferred into cryotubes. After storage in LN2 for 2 to 4 weeks, the oocytes were warmed by dropping the microdroplets directly into 2.5 mL of warming solution (0.4 M trehalose in BM) kept in a 35-mm Petri dish on a 42°C hotplate for less than 1 min. Then, the warming dish was placed on a 38°C hotplate and COC were consecutively transferred for 1-min periods into BM containing 0.2, 0.1, or 0.05 M trehalose at 38°C. The COC were matured in vitro for 44 h using porcine oocyte medium (POM) supplemented with 10% follicular fluid (Yoshioka et al. 2008 J. Reprod. Dev. 54, 208–213). Then, oocytes were denuded, and their live/dead status and nuclear maturation were determined by their morphology and the presence of the first polar body, respectively. To assess their developmental competence, vitrified and non-vitrified (control) oocytes were in vitro fertilized (IVF; Kikuchi et al. 2002 Biol. Reprod. 66, 1033–1041) and then in vitro cultured in porcine zygote medium-5 (PZM-5; Yoshioka et al. 2008 J. Reprod. Dev. 54, 208–213). Blastocyst rates were recorded on Days 5, 6, and 7 of culture (Day 0 = the day of IVF). The experiment was replicated 4 times. Data were analysed with 1-way ANOVA and the Tukey test. The results revealed that 86.4% (364/424) of oocytes survived after vitrification, which was significantly lower (P < 0.05) than that of controls [100% (326/326)]. Live oocytes in vitrified and control groups did not differ statistically in terms of nuclear maturation (63.9 v. 65.3%). Blastocyst rates of surviving vitrified oocytes were significantly lower compared with controls on Days 5 (2.4 v. 12.7%), 6 (4.8 v. 17.6%), and 7 (5.6 v. 18.4%). To test their ability to develop to term, 16 and 27 blastocysts on Day 5 developing from vitrified COC were transferred into 2 recipients. Both recipients became pregnant and farrowed a total of 10 live piglets (4 and 6 piglets, respectively). These data demonstrate that large groups of immature porcine oocytes could be cryopreserved by this method showing high survival and maturation rates. Furthermore, despite a low rate of blastocyst development, transfer of Day-5 blastocysts generated from vitrified oocytes resulted in piglet production for the first time in the world. Partially supported by JSPS and HAS under the Japan-Hungary Research Cooperative Program.


2008 ◽  
Vol 20 (1) ◽  
pp. 118 ◽  
Author(s):  
M. C. Gómez ◽  
N. Kagawa ◽  
C. E. Pope ◽  
M. Kuwayama ◽  
S. P. Leibo ◽  
...  

The ability to cryopreserve female gametes efficiently holds immense economic and genetic implications. The purpose of the present project was to determine if domestic cat oocytes could be cryopreserved successfully by use of the Cryotop method. We evaluated (a) cleavage frequency after in vitro fertilization (IVF) v. intracytoplasmic sperm injection (ICSI) of in vivo- and in vitro-matured oocytes after vitrification, and (b) fetal development after transfer of resultant embryos into recipients. In vivo-matured cumulus–oocyte complexes (COCs) were recovered from gonadotropin-treated donors at 24 h after LH treatment, denuded of cumulus cells, and examined for the presence of the first polar body (PB). In vitro-matured COCs were obtained from ovaries donated by local clinics and placed into maturation medium for 24 h before cumulus cells were removed and PB status was determined. Oocytes were cryopreserved by the Cryotop method (Kuwayama et al. 2005 Reprod. Biomed. Online 11, 608–614) in a vitrification solution consisting of 15% DMSO, 15% ethylene glycol, and 18% sucrose. For IVF, oocytes were co-incubated with 1 � 106 motile spermatozoa mL–1 in droplets of modified Tyrode's medium in 5% CO2/air at 38�C (Pope et al. 2006 Theriogenology 66, 59–71). For ICSI, an immobilized spermatozoon was loaded into the injection pipette, which was then pushed through the zona pellucida into the ooplasm. After a minimal amount of ooplasm was aspirated into the pipette, the spermatozoon was carefully expelled, along with the aspirated ooplasm. After ICSI, or at 5 or 18 h post-insemination, in vivo- and in vitro-matured oocytes, respectively, were rinsed and placed in IVC-1 medium (Pope et al. 2006). As assessed by normal morphological appearance after liquefaction, the survival rate of both in vivo- and in vitro-matured oocytes was >90% (93–97%). For in vitro-matured oocytes, cleavage frequencies after IVF of control and vitrified oocytes were 73% (16/22) and 53% (30/57), respectively, as compared to 68% (19/28) after ICSI of vitrified oocytes (P > 0.05). For in vivo-matured oocytes, cleavage frequencies after IVF of control and vitrified oocytes were 55% (18/33) and 35% (6/17), respectively, compared to 50% (10/20) after ICSI of vitrified oocytes (P > 0.05). At 18–20 h after ICSI, 18 presumptive zygotes and four 2-cell embryos derived from vitrified in vitro-matured oocytes and 19 presumptive zygotes produced from seven in vivo-matured and 12 in vitro-matured vitrified oocytes were transferred by laparoscopy into the oviducts of two recipients at 24–26 h after oocyte retrieval. The two recipients were 9-month-old IVF/ET-derived females produced with X-sperm sorted by flow cytometry. At ultrasonography on Day 22, both recipients were pregnant, with three live fetuses observed in one recipient and one live fetus seen in the second recipient. On Day 63 and Day 66 of gestation, four live kittens were born, without assistance, to the two recipients. The one male and three female kittens weighed an average of 131 g. In summary, in vivo viability of zygotes/embryos produced by ICSI of cat oocytes vitrified by the Cryotop method was demonstrated by the birth of live kittens following transfer to recipients.


Reproduction ◽  
2002 ◽  
pp. 455-465 ◽  
Author(s):  
YH Choi ◽  
CC Love ◽  
LB Love ◽  
DD Varner ◽  
S Brinsko ◽  
...  

This study was undertaken to evaluate the development of equine oocytes in vitro and in vivo after intracytoplasmic sperm injection (ICSI) with either fresh or frozen-thawed spermatozoa, without the use of additional activation treatments. Oocytes were collected from ovaries obtained from an abattoir and oocytes classified as having expanded cumulus cells were matured in M199 with 10% fetal bovine serum and 5 microU FSH ml(-1). After 24-26 h of in vitro maturation, oocytes with a first polar body were selected for manipulation. Fresh ejaculated stallion spermatozoa were used for the experiment after swim-up for 20 min in sperm-Tyrode's albumen lactate pyruvate. Frozen-thawed spermatozoa from the same stallion were treated in a similar way. Spermatozoa were immobilized and injected into the oocytes using a Piezo drill. Presumptive zygotes were cultured in G1.2 medium for 20 or 96 h after the injection was administered, or were transferred to the oviducts of recipient mares and recovered 96 h later. In addition, bovine oocytes with first polar bodies were injected with the two types of stallion spermatozoa and fixed 20 h after injection to examine pronuclear formation. Fertilization rate (pronucleus formation and cleavage) at 20 h after injection of spermatozoa was not significantly different between fresh and frozen-thawed sperm groups in either equine or bovine oocytes. Pronucleus formation after injection of spermatozoa into bovine oocytes was significantly higher than that for equine oocytes (P < 0.05). There were no significant differences in cleavage rate or average number of nuclei at 96 h between equine oocytes injected with fresh or frozen-thawed spermatozoa. However, embryos developed in vivo for 96 h had a significantly higher number of nuclei in both sperm treatments compared with those cultured in vitro. These results indicate that good activation rates may be obtained after injection of either fresh or frozen-thawed equine spermatozoa without additional activation treatment. Injection of frozen-thawed equine spermatozoa results in similar embryo development to that obtained with fresh equine spermatozoa. In vitro culture of equine zygotes in G1.2 medium results in a similar cleavage rate but reduced number of cells compared with in vivo culture within the oviduct. Bovine oocytes may be useful as models for assessing sperm function in horses.


2004 ◽  
Vol 16 (2) ◽  
pp. 195
Author(s):  
Y.H. Choi ◽  
D.D. Varner ◽  
K. Hinrichs

Research on in vitro culture of equine embryos has been scant, due to failure of equine in vitro fertilization to be repeatably successful. We have recently obtained high fertilization rates of equine oocytes via intracytoplasmic sperm injection (ICSI) using a piezo drill (Choi et al., 2002 Reproduction 123, 455–465). Culture of presumptive zygotes in G1.2/2.2 medium resulted in 63% cleavage and an average of 15 cells at 4d, but only 2 to 9% blastocyst development at 7 days (Choi et al., 2003 Theriogenology 59, 1219–1229). In the present study, we evaluated the effect of two different culture media, G1.3/G2.3 v. DMEM/F-12, with or without FBS, on blastocyst development after ICSI. Oocytes were collected from slaughterhouse-derived ovaries by follicular scraping and were matured in vitro for 24h in M199 with 10% FBS and 5μUmL−1 FSH. After culture, oocytes having a polar body (198/305; 65%) were fertilized by ICSI with frozen-thawed equine sperm using a piezo drill. Presumptive zygotes were cultured in 1 of 4 media: G1.3/G2.3 (which includes 0.8% BSA) with or without 10% FBS, or in DMEM/F-12 with 0.5% BSA, with or without 10% FBS. Culture was performed in microdroplets at 5μL/zygote under oil at 38.2°C in an atmosphere of 5% CO2, 5% O2 and 90% N2 for 7.5 days. In G1.3/2.3 treatments, G1.3 media were completely refreshed at 48h, zygotes were transferred to G2.3 (with or without FBS as per the first stage) at 96h, and were completely refreshed with the same media at 144h. In DMEM/F-12 treatments, media were completely refreshed every other day. Three to 5 replicates were performed in each treatment, and data were analyzed by chi-square test. There were no significant differences in cleavage rates (59–64%) among treatments. The rate of development to blastocyst, per oocyte injected, in G1.3/G2.3/BSA (1/49, 2%) was significantly lower (P&lt;0.05) than that for the other three treatments: G1.3/2.3/BSA/FBS (9/49, 18%), DMEM/F-12/BSA (9/50, 18%), or DMEM/F-12/BSA/FBS (10/50, 20%). There was no significant difference in blastocyst development among the latter three treatments. These findings indicate that G1.3/2.3 media with BSA only do not adequately support growth of equine embryos. Development of up to 20% of injected oocytes to the blastocyst stage in G media supplemented with FBS, in DMEM/F-12/BSA or in DMEM/F-12/BSA/FBS represents the highest in vitro equine blastocyst rate in medium alone (i.e. without co-culture) yet reported. The success of DMEM/F-12 as an embryo culture medium may provide a relatively simple basis for equine in vitro culture programs. To determine whether this medium was able to support further developmental competence, we cultured equine embryos resulting from nuclear transfer of in vitro-matured oocytes in DMEM/F-12+10% FBS (without BSA). We transferred 4 resulting blastocysts to recipient mares by transcervical transfer; one pregnancy is ongoing at 230d gestation at the time of this writing. This work was supported by the Link Equine Research Endowment Fund, Texas A&amp;M University.


2019 ◽  
Vol 24 (2) ◽  
pp. 274-292
Author(s):  
Johanna Leiva Revilla ◽  
Carolina Maside ◽  
Luis Vieira ◽  
Jesús Cadenas ◽  
Ana Clara Ferreira Acioly ◽  
...  

Most anticancer drugs like doxorubicin (DXR) have low specificity that results in undesirable effects especially when it comes to collateral effects on reproduction. Plants are excellent sources when searching for new drugs. Auxemma oncocalyx (A. oncocalyx) and its main component Oncocalyxone A (onco A) have anti-tumoral activity and are less toxic than DXR in reproductive parameters. However, there are no studies on the action of these drugs regarding the porcine in vitro oocyte competence and embryo development. The aim of this study was to evaluate the effect of A. oncocalyx and onco A exposure during in vitro maturation (IVM) of oocytes (Experiment 1) or in vitro embryo culture (IVC) (Experiment 2) on the oocyte developmental competence. For experiment 1, COCs were distributed in IVM medium alone (control) or supplemented with DXR (0.3 g/mL), A. oncocalyx (1.2 g/mL) and onco A (1 g/mL). Then, oocytes were submitted to in vitro fertilization (IVF) and in vitro embryo culture. For experiment 2, zygotes were cultured with DXR, A. oncocalyx and onco A for 7 days. Viability, maturation, fertilization and embryo developmental parameters were evaluated in both experiments. In experiment 1; DXR, A. oncocalyx and onco A reduced (P<0.05) oocyte viability  and  IVM  efficiency.  Onco A increased (P<0.05) the meiotic resumption. After IVF, all drugs reduced (P<0.05) viability, IVF efficiency and percentage of cleaved embryos, nevertheless, only DXR decreased the percentage of blastocyst. In experiment 2; all drugs reduced (P<0.05) the percentage of penetration, but only DXR and onco A decreased (P<0.05) IVF efficiency. DXR and A. oncocalyx decreased (P<0.05) the percentage of cleaved embryo, but had no effect on blastocyst formation. In conclusion, the addition of DXR during IVM or IVC negatively affected the IVF efficiency and cleavage rate. In addition, the exposure of COCs to DXR only during IVM was more detrimental to oocyte viability and blastocyst formation than A. oncocalyx and onco A.


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