scholarly journals Vitrification of immature oocytes of goats in Bangladesh

2019 ◽  
Vol 35 (1-2) ◽  
pp. 7-12
Author(s):  
MN Sharif ◽  
SM Choudhury ◽  
MM Rahman ◽  
MM Rahman ◽  
NS Juyena ◽  
...  
Keyword(s):  
Culture Medium ◽  
Assisted Reproductive Technologies ◽  
Polar Body ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Step Procedure ◽  
Inverted Microscope ◽  
Maturation Rate ◽  
Humidified Air

Cryopreservation of oocytes and embryos by vitrification can have advantages in assisted reproductive technologies (ARTs) in mammals. The aim of this study was to establish an effective vitrification procedure and cryodevice for goat’s oocytes in Bangladesh. Cumulus oocyte complexes (COCs) were collected from ovaries from slaughterhouse. COCs with more than 3 layers of cumulus cells were selected. COCs were vitrified by two-step procedure using 7.5% and 15% dimethyl sulphoxide (DMSO) as cryoprotective agent (CPA), loaded on Cryotop or French mini-straw, then directly plunged into liquid nitrogen (LN2). Then the COCs containing Cryotop or French mini-straws were warmed in 0.25 M sucrose and 20% FBS-supplemented tissue culture medium (TCM) 199 followed by in vitro culture in 50 μl droplets of bicarbonate-buffered TCM 199 supplemented with 10% FBS, pyruvate, FSH and oestradiol for 24 h at 39°C with 5% CO2 in humidified air. After maturation culture, oocytes were denuded and examined under inverted microscope for presence of polar body as the indication of maturation. The in vitro maturation rate of goat’s oocytes after vitrification and warming was 39.3 ± 6.8%, 31.3 ± 9.4%, 61.6 ± 14.2% when using Cryotop (cryodevice), French mini-straws and without vitrification (control), respectively. Maturation rate was significantly higher (P<0.05) without vitrification. It is suggested that both Cryotop and French mini-straw are efficient cryodevices for vitrification of goat’s oocytes and further investigation is required to optimize the protocol for vitrification and warming procedure for the satisfactory survival of goat’s oocytes. The Bangladesh Veterinarian (2018) 35(1&2): 7-12

Mechanism of the adverse effect of hyaluronidase used for oocyte denudation on early development of bovine embryos

Zygote ◽  
2021 ◽  
pp. 1-5
Author(s):  
Shiori Ashibe ◽  
Kanade Irisawa ◽  
Ken Yokawa ◽  
Yoshikazu Nagao
Keyword(s):  
Treatment Group ◽  
Assisted Reproductive Technologies ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Control Group ◽  
Free Calcium ◽  
Parthenogenetic Development ◽  
Early Embryos ◽  
Bovine Oocytes

Summary Hyaluronidase is widely used in animal and human assisted reproductive technologies (ARTs) to remove cumulus cells around oocytes. However, adverse effects of hyaluronidase treatment, such as increased rates of degeneration and parthenogenesis, have been found after treatment of human and mouse oocytes. Currently, the mechanism(s) of the detrimental effects are unclear. The present study was initiated to identify the mechanism of adverse responses to hyaluronidase treatment in bovine oocytes and early embryos. Cumulus cells were removed from cumulus–oocyte complexes (COCs) with or without hyaluronidase and the oocytes were subjected to intracytoplasmic sperm injection (ICSI) or in vitro fertilization (IVF). Significantly lower rates of blastocyst formation were obtained in the hyaluronidase treatment group after ICSI (22.4%) and IVF (21.2%) compared with the non-hyaluronidase control groups: 36.1% after ICSI and 30.4% after IVF. Next, we examined the effect of hyaluronidase on parthenogenetic development rates and on the cytoplasmic levels of free calcium ions (Ca2+), reactive oxygen species (ROS) and reduced glutathione (GSH). No differences in parthenogenesis rates were found between treated and untreated groups. Ca2+ levels in oocytes from the hyaluronidase treatment group indicated using mean fluorescence intensity were significantly higher (68.8 ± 5.3) compared with in the control group (45.0 ± 2.5). No differences were found in the levels of ROS or GSH between the treated and untreated groups. We conclude that hyaluronidase might trigger an increase in Ca2+ levels in oocytes, resulting in a decreased potential for normal embryonic development.

98 BLASTOCYST DEVELOPMENT RATE OF CLONED CAT EMBRYOS USING SERIAL CLONING

2007 ◽  
Vol 19 (1) ◽  
pp. 166
Author(s):  
X. J. Yin ◽  
H. S. Lee ◽  
E. G. Choi ◽  
X. F. Yu ◽  
B. H. Choi ◽  
...  
Keyword(s):  
Nuclear Transfer ◽  
Second Generation ◽  
Assisted Reproductive Technologies ◽  
Polar Body ◽  
Donor Cell ◽  
Fibroblast Cell ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Blastocyst Development ◽  
First Polar Body

Domestic cats are a useful research model to develop assisted reproductive technologies for the conservation of endangered felids. Previously, we produced cloned offspring derived from somatic cell nuclear transfer of ear skin fibroblasts obtained from a deaf, odd-eyed, male Turkish Angora. The aim of this study was to assess the cloning efficiency of the fibroblasts derived from a cloned cat. Fibroblast cell lines were established from 6-mm skin biopsies taken from a deaf, odd-eyed, male Turkish Angora and his clone. The protocol for nuclear transfer was described previously (Yin et al. 2005 Reproduction 129, 245–249). Briefly, cumulus cells were removed from the ova by gently pipetting them into TCM-199 supplemented with 0.1% hyaluronidase. The denuded oocytes were then cultured in TCM-199 supplemented with 0.2 �g mL-1 demecolcine for 1 h and placed into TCM-199 containing 5 �g mL-1 cytochalasin B and 0.2 �g mL-1 demecolcine. The first polar body and protruded chromatin plate were removed with a beveled micropipette. Micromanipulation was used to place a single donor cell nucleus into the perivitelline space of enucleated ova. The ovum-cell couplets were fused and pulse activated. The activated couplets were cultured in 500 �L of CRI medium supplemented with 0.3% BSA for 2 days. The cleaved embryos were cultured in CRII medium supplemented with 10% FBS for 5 days. The cleavage and blastocyst development rates were 38.5% and 3.5% for second generation cloned embryos. A total of 310 second generation cloned embryos were transplanted to 9 surrogates, and 2 pregnancies at 30 days were determined by ultrasonography. One pregnancy was aborted at 40 days of gestation; the second pregnancy continued. These results indicate that the serial cloning of a cat can be generated efficiently up until pregnancy. This work was supported by KOSEF (grant #M10525010001-05N2501-00110).

Dose-dependent effects of gonadotropin on oocyte developmental competence and apoptosis

2011 ◽  
Vol 23 (8) ◽  
pp. 990 ◽  
Author(s):  
Shan Liu ◽  
Huai L. Feng ◽  
Dennis Marchesi ◽  
Zi-Jiang Chen ◽  
Avner Hershlag
Keyword(s):  
Embryo Development ◽  
Assisted Reproductive Technologies ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Developmental Competence ◽  
Beneficial Effects ◽  
Nuclear Maturation ◽  
High Concentrations ◽  
Vitro Development

The aim of the present study was to evaluate the effect of gonadotropins (Gn) on oocyte maturation, developmental competence and apoptosis in an animal model. Bovine cumulus–oocyte complexes (COCs) were matured for 24 h in media supplemented with varying concentrations of Bravelle (B), B + Menopur (B + M) or B + Repronex (B + R) (Ferring Pharmaceuticals, Parsiappany, NJ, USA). Then, nuclear maturation, embryo development, and apoptosis in cumulus cells and oocytes were evaluated. Low to moderate Gn concentrations (75–7500 mIU mL–1) effectively improved nuclear maturation and in vitro development. Higher concentrations of Gn (75 000 mIU mL–1) did not have any added beneficial effects and nuclear maturation and blastocyst rates in the presence of these concentrations were comparable to control (P > 0.05). Most COCs showed slight apoptosis when exposed to 75, 750 and 7500 mIU mL–1 Gn; however, when the concentration was increased to 75 000 mIU mL–1, the proportion of moderately apoptotic COCs increased. In conclusion, extremely high concentrations of Gn have detrimental effects on oocyte nuclear maturation and embryo development and increase apoptosis in cumulus cells, suggesting the importance of judicious use of Gn in assisted reproductive technologies (ART).

176 IN VITRO MATURATION OF DOG OOCYTES IN CANINE FOLLICULAR FLUID

2014 ◽  
Vol 26 (1) ◽  
pp. 202
Author(s):  
K. Reynaud ◽  
S. Canguilhem ◽  
S. Thoumire ◽  
S. Chastant-Maillard
Keyword(s):  
Follicular Fluid ◽  
In Vitro Maturation ◽  
Assisted Reproductive Technologies ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Control Group ◽  
Limiting Factor ◽  
Cytoplasmic Maturation

In the canine species, assisted reproductive technologies, especially in vitro maturation (IVM) and IVF, are still ineffective. The main limiting factor remains the immaturity of the oocytes collected from anestrus ovaries. The ability of an oocyte to reach the MII stage in vitro is linked to the diameter of its follicle and anestrus oocytes, collected from small (<1 mm) follicles, are profoundly immature (De Lesegno et al. 2008). The objective of this study was to improve cytoplasmic quality by mimicking in vivo conditions; that is, to test the effect of pure preovulatory follicular fluid (FF) on survival and IVM rates of anestrus dog oocytes, in order to improve the nuclear and cytoplasmic maturation of these immature oocytes. Follicular fluids samples were collected from 54 Beagle bitches at 2 stages: before the LH peak (n = 23 bitches) and after the LH peak (n = 31 bitches). Only follicular fluid samples from large (>4 mm) follicles were collected and pooled by stage. Control oocytes were matured in 20% FCS/M199 medium. Groups of 5 oocytes were in vitro matured in 30 μL of follicular fluid, in half-area 96-well plates (5% CO2, 38°C). After 72 h of IVM, oocytes were denuded, fixed, and stained for DNA and tubulin before observation by confocal microscopy, and nuclear stages were classified as GV-A to GV-E, MI, and MII (Reynaud et al. 2012). A total of 460 oocytes were collected from 13 anestrus bitches and allocated to either the control medium (n = 155), the Pre-LH FF (n = 145) or the Post-LH FF (n = 160) groups. After 72 h of IVM, the morphology of the cumulus–oocyte complexes (COC) in the post-LH group was different from that of the others: cumulus cells appeared more compact and darker. Analysis of the nuclear stages showed that the degeneration rate was significantly higher (P < 0.05) in the post-LH group (58.7%) than in the pre-LH (40.9%) or in the control group (34.4%). No significant differences (P > 0.05) were observed between the 3 groups in the rate of immature GVA-B oocytes (36.4, 28.5, and 25.3% in the control, Pre-LH, and Post-LH groups, respectively), in the rate of meiotic resumption (GV-C/D/E, MI, MII stages, 44.4, 51.9, and 38.7% in the control, Pre-LH, and Post-LH groups, respectively). Metaphase II rates were not significantly different (12.1, 8.6, and 4.8% in the control, Pre-LH, and Post-LH groups, respectively). In conclusion, canine COC may survive when exposed to IVM in pure follicular fluid, but the degeneration rate was higher in the post-LH group. The presence of follicular fluid did not inhibit meiosis resumption, but did not significantly improve IVM rates. To better mimic in vivo conditions, IVM in a sequence of media, such as IVM in follicular fluid followed by IVM in oviducal fluid remains to be tested.

scholarly journals Human Cumulus Cells in Long-Term In Vitro Culture Reflect Differential Expression Profile of Genes Responsible for Planned Cell Death and Aging—A Study of New Molecular Markers

Cells ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 1265
Author(s):  
Błażej Chermuła ◽  
Wiesława Kranc ◽  
Karol Jopek ◽  
Joanna Budna-Tukan ◽  
Greg Hutchings ◽  
...  
Keyword(s):  
Cell Death ◽  
In Vitro Culture ◽  
Expression Analysis ◽  
Assisted Reproductive Technologies ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Oocyte Quality ◽  
Genetic Profile

In the ovarian follicle, maturation of the oocyte increases in the presence of somatic cells called cumulus cells (CCs). These cells form a direct barrier between the oocyte and external environment. Thanks to bidirectional communication, they have a direct impact on the oocyte, its quality and development potential. Understanding the genetic profile of CCs appears to be important in elucidating the physiology of oocytes. Long-term in vitro culture of CCs collected from patients undergoing controlled ovarian stimulation during in vitro fertilization procedure was conducted. Using microarray expression analysis, transcript levels were assessed on day 1, 7, 15, and 30 of culture. Apoptosis and aging of CCs strictly influence oocyte quality and subsequently the outcome of assisted reproductive technologies (ART). Thus, particular attention was paid to the analysis of genes involved in programmed cell death, aging, and apoptosis. Due to the detailed level of expression analysis of each of the 133 analyzed genes, three groups were selected: first with significantly decreased expression during the culture; second with the statistically lowest increase in expression; and third with the highest significant increase in expression. COL3A1, SFRP4, CTGF, HTR2B, VCAM1, TNFRSF11B genes, belonging to the third group, were identified as potential carriers of information on oocyte quality.

scholarly journals Quadrupling efficiency in production of genetically modified pigs through improved oocyte maturation

2017 ◽  
Vol 114 (29) ◽  
pp. E5796-E5804 ◽  
Author(s):  
Ye Yuan ◽  
Lee D. Spate ◽  
Bethany K. Redel ◽  
Yuchen Tian ◽  
Jie Zhou ◽  
...  
Keyword(s):  
Assisted Reproductive Technologies ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Oocyte Quality ◽  
Blastocyst Stage ◽  
Vitro Fertilization ◽  
Fourfold Increase

Assisted reproductive technologies in all mammals are critically dependent on the quality of the oocytes used to produce embryos. For reasons not fully clear, oocytes matured in vitro tend to be much less competent to become fertilized, advance to the blastocyst stage, and give rise to live young than their in vivo-produced counterparts, particularly if they are derived from immature females. Here we show that a chemically defined maturation medium supplemented with three cytokines (FGF2, LIF, and IGF1) in combination, so-called “FLI medium,” improves nuclear maturation of oocytes in cumulus–oocyte complexes derived from immature pig ovaries and provides a twofold increase in the efficiency of blastocyst production after in vitro fertilization. Transfer of such blastocysts to recipient females doubles mean litter size to about nine piglets per litter. Maturation of oocytes in FLI medium, therefore, effectively provides a fourfold increase in piglets born per oocyte collected. As they progress in culture, the FLI-matured cumulus–oocyte complexes display distinctly different kinetics of MAPK activation in the cumulus cells, much increased cumulus cell expansion, and an accelerated severance of cytoplasmic projections between the cumulus cells outside the zona pellucida and the oocyte within. These events likely underpin the improvement in oocyte quality achieved by using the FLI medium.

scholarly journals The effect of lysophosphatidic acid-supplemented culture medium on human immature oocytes matured in vitro

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Qigui Xie ◽  
Yaxin Xing ◽  
Jianhong Zhou ◽  
Ling Wang ◽  
Jie Wu ◽  
...  
Keyword(s):  
Gene Ontology ◽  
Oocyte Maturation ◽  
Lysophosphatidic Acid ◽  
Culture Medium ◽  
Cumulus Cells ◽  
Mapk Signaling ◽  
Gene Ontology Analysis ◽  
Maturation Rate ◽  
Upregulated Genes

Abstract Background Lysophosphatidic acid-supplemented culture medium significantly increases the oocyte maturation rate in vitro. However, potential targets and pathways involved remain unknown. Methods A total of 43 women, who underwent cesarean section and aged between 18 and 35 years with good health, were included in this study. Immature oocytes were obtained and cultured with 10 µM lysophosphatidic acid. After culture, oocyte maturation was assessed and oocytes and cumulus cells were collected for RNA sequencing. Hierarchical indexing for spliced alignment of transcripts 2 method was used to align clean reads to the human genome. The featureCounts and edgeR package were used to calculate gene expression and analyze differences between groups respectively. ClusterProfiler program was used to perform Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis. Results Oocyte maturation rate increased significantly following 48 h culture with lysophosphatidic acid. In cumulus cells, Gene Ontology analysis revealed the top 20 items enriched by upregulated genes and downregulated genes respectively; Kyoto Encyclopedia of Genes and Genomes analysis showed that upregulated genes in the treatment group were enriched in TNF signaling and insulin secretion pathways and downregulated genes were enriched in TNF signaling and cell adhesion molecules. In oocytes, Gene Ontology analysis revealed the top 20 items enriched by upregulated genes and downregulated genes respectively; Kyoto Encyclopedia of Genes and Genomes analysis showed that upregulated genes in the treatment group were enriched in MAPK signaling, gap junction, and cell cycle pathways and downregulated genes were enriched in MAPK signaling, estrogen signaling, RAP1 signaling, and gap junction pathways. Conclusions Lysophosphatidic acid in culture medium enhances human oocyte maturation in vitro and the identified some potential pathways may associate with oocyte maturation.

65 THE EFFECTS OF CUMULUS CELLS ON DEVELOPMENTAL RATES OF VITRIFIED MOUSE OOCYTES IN C57BL/6J STRAIN

2013 ◽  
Vol 25 (1) ◽  
pp. 180
Author(s):  
N. Kashiwazaki ◽  
N. Kohaya ◽  
K. Fujiwara ◽  
K. Furui ◽  
J. Ito
Keyword(s):  
Ethylene Glycol ◽  
Assisted Reproductive Technologies ◽  
Formation Rate ◽  
Cumulus Cells ◽  
Analysis Data ◽  
Reproductive Technologies ◽  
Developmental Competence ◽  
Mouse Oocytes ◽  
Free Media

Unfertilized oocytes are one of the most desired germ-cell stages for cryopreservation because these cryopreserved oocytes can be used for assisted reproductive technologies, including IVF and intracytoplasmic sperm injection. However, in general, the fertility and developmental ability of cryopreserved oocytes are still low. We have recently reported that, in the presence of surrounding cumulus cells, matured mouse oocytes vitrified using calcium-free media and ethylene glycol retain their developmental competence (Kohaya et al. 2011 J. Reprod. Dev. 57, 675–680). Since the previous study was carried out using ICR mice (closed colony), we examined whether our protocol can be applied for C57BL/6J mice (inbred strain), which are commonly used for production of transgenic and knockout mice. The effect of cumulus cells on the ability of C57BL/6J mouse oocytes to be fertilized and develop in vitro was examined. Cumulus oocyte complexes (COC) derived from female mice with super ovulation were collected by flushing. Cumulus cells were removed for a portion of the oocytes (DO) using hyarulonidase. Oocytes from both treatment groups (COC and DO) were then vitrified according to the protocol we previously reported (Kohaya et al. 2011). After warming, vitrified COC and DO were used for IVF. All percentage data were subjected to arcsine transformation before statistical analysis. Data were analyzed by one-way ANOVA and Tukey’s test. Significance was considered at P < 0.05. The pronuclear formation rate of vitrified DO after IVF (20/58, 33.3%) was reduced compared with vitrified COC (55/90, 62.1%). Vitrified COC showed significantly (P < 0.05) higher developmental ability to develop into the 2-cell (50/90, 57.0%) and blastocyst stages (42/90, 45.9%) compared with vitrified DO [24.8% (16/58) and 18.4% (11/58), respectively]. The vitrified COC developed to term at a high success rate (51/90, 56.7%) being equivalent to the rate obtained with IVF using fresh COC (52/90, 57.8%). Taken together, the current results clearly demonstrate that, in the presence of surrounding cumulus cells, matured mouse oocytes vitrified using calcium-free media and ethylene glycol retain their developmental competence. These findings will contribute to improve oocytes vitrification in not only experimental animals but also in clinical application in human infertility.

165 In vitro maturation of ovine and caprine oocytes during breeding and nonbreeding seasons

2019 ◽  
Vol 31 (1) ◽  
pp. 207
Author(s):  
M. Markle ◽  
C. K. Mak ◽  
V. Medina ◽  
C. R. F. Pinto
Keyword(s):  
Breeding Season ◽  
In Vitro Maturation ◽  
Statistical Significance ◽  
Polar Body ◽  
Cumulus Cells ◽  
Nonbreeding Season ◽  
Nuclear Maturation ◽  
Significant Difference ◽  
Maturation Rate

The current study investigated the in vitro meiotic competence of ovine and caprine oocytes that underwent nuclear maturation during the breeding and nonbreeding seasons. We hypothesised that maturation rates of ovine and caprine oocyte would be significantly lower during the nonbreeding season. Ovine (Katahdin crossbred) and caprine (mainly Spanish crossbred) ovaries were collected from a local abattoir in the southern United States. Age of the animals was not determined. Cumulus-oocyte complexes (COC) were harvested by slicing the ovaries and searching using a stereomicroscope. Oocytes with more than 3 layers of unexpanded cumulus cells and with evenly granulated cytoplasm were selected for in vitro maturation (IVM). A commercial bovine IVM media (IVF Bioscience, Falmouth, United Kingdom) was used throughout the study. After 24h of IVM, ovine and caprine oocytes were denuded and oocytes with an extruded polar body (meiotic metaphase II oocytes) were considered to have reached nuclear maturation. The seasons in this study were defined as follows: breeding season=September to April and nonbreeding season=May to July. The presence of corpus hemorrhagicum or corpus luteum in at least 70% of the ovaries indicated the breeding season for the animals. Proportions of oocytes undergoing nuclear maturation were analysed using a two-tailed Chi-squared test. Statistical significance was set at P ≤ 0.05. The ovine maturation rate was 59% (65/111) and 49% (254/519) and the caprine maturation rate was 70% (39/56) and 40% (64/162) during the breeding and nonbreeding seasons, respectively. These results show a significant difference in nuclear maturation for caprine oocytes (P&lt;0.001) during the breeding and nonbreeding seasons; however, there was no significant difference in nuclear maturation for ovine oocytes (P=0.06) during the breeding and nonbreeding seasons. High environmental temperatures during the nonbreeding season may have had detrimental effects on oocyte nuclear maturation in caprine but not in ovine oocytes. Why oocytes from these 2 species differ on how they are adversely affected by season remains to be elucidated.

scholarly journals In vitro maturation of collared peccary (Pecari tajacu) oocytes after different incubation times

2018 ◽  
Vol 38 (9) ◽  
pp. 1863-1868 ◽  
Author(s):  
Alana A. Borges ◽  
Maria V.O. Santos ◽  
Luiza B. Queiroz Neta ◽  
Moacir F. Oliveira ◽  
Alexandre R. Silva ◽  
...  
Keyword(s):  
In Vitro Maturation ◽  
Polar Body ◽  
Morphological Characteristics ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Fisher Exact Test ◽  
First Polar Body ◽  
Collared Peccary ◽  
Culture Environment

ABSTRACT: Oocyte in vitro maturation (IVM) is the first step of the in vitro reproductive technologies that enables mature oocytes to be generated ex vivo and after used for embryo production. In this sense, the establishment of culture environment, as oocyte incubation time, is essential for the success of the IVM. Therefore, the study was carried out to investigate the relationship between the meiotic potential and the IVM times of collared peccary oocytes, wild mammals of great commercial and ecological interest. Thus, ovaries were collected of females derived from captivity and transported to the laboratory within 1 hour of slaughtering. The oocytes derived from follicles (3-6mm in diameter) were recovered by aspirated and sliced. Good quality oocytes (evenly granulated cytoplasm with a least one layer of surrounding cumulus cells) were selected and subjected to culture in TCM 199 supplemented with 10µg/mL FSH, 10% FBS and 100µM cysteamine at 38.5°C, 5% CO2 and maximum humidity for 24 or 48 hours. After the incubation period, the nuclear status, the presence of first polar body and the expansion of cumulus cells of oocytes were assessed. The data obtained were analyzed by Fisher exact test (P<0.05). A total of four sessions (2-3 females per session) were performed, resulting in eighteen aspirated and sliced ovaries with normal morphological characteristics. An oocyte recovery rate of about 83.1% (59/71) was obtained with 3.3 oocytes/ovary and 2.3 viable oocytes/ovary. After different incubation times, differences (P<0.05) were observed in 24 and 48 hours for expansion of the cumulus cells (38.1% vs. 100%), presence of first polar body (52.4% vs. 90.5%) and nuclear status in second metaphase (19.0% vs. 76.2%), respectively. In conclusion, 48 hours is suitable time for the in vitro maturation of oocytes derived from collared peccaries when compared to the time of 24 hours, according to the meiotic potential observed. Additional studies should be conducted to improve the quality of the oocyte culture environment, as medium composition, aiming to obtain viable mature oocytes for other in vitro biotechnologies.

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