269 EFFECTS OF REPRODUCTIVE STATUS AND OOCYTE QUALITY ON THE DEVELOPMENTAL COMPETENCE OF OOCYTES FOLLOWING IN VITRO PRODUCTION IN DOMESTIC CAT

2006 ◽  
Vol 18 (2) ◽  
pp. 242
Author(s):  
B. Agung ◽  
P. Wongsrikeao ◽  
H. Fuchieda ◽  
T. Otoi
Keyword(s):  
Reproductive Cycle ◽  
Bovine Serum ◽  
Cell Mass ◽  
Cumulus Cell ◽  
Oocyte Quality ◽  
Domestic Cat ◽  
Developmental Competence ◽  
Human Menopausal Gonadotropin ◽  
Significant Difference

A recent study showed that the developmental competence of cat oocytes after IVM and IVF was affected by the estrous cycle stage of the donor (Freistedt et al. 2001 Biol. Reprod. 65, 9-13). This study was conducted to examine the effect of the cat reproductive cycle stage and the oocyte quality on the developmental competence of the oocyte following IVF production. Cat ovaries were collected at veterinary clinics and stored at 4�C for 24 h. Based on the presence or absence of follicles and corpora lutea, the ovaries were classified into the luteal, follicular, or inactive stage. Cumulus oocyte complexes (COCs) from the different stage ovaries were separated at recovery into three ranks (A, B, and C) according to pigmentation, uniformity and smoothness of ooplasm, and amount of surrounding cumulus cell mass and were cultured separately in 100 �L drops of maturation medium (TCM-199), supplemented with 0.4% bovine serum albumin, 0.1 IU/mL (human menopausal gonadotropin (HMG), 10 IU/mL HCG, 1 �g/mL 17�-estradiol, and 100 �g/mL gentamicin) for 24-h at 38�C, 5% CO2 in air. After 24-h in vitro culture, the oocytes were transferred into 100 �L sperm microdrops of Brackett-Oliphant medium (2 � 106 sperm/mL) for fertilization and were co-incubated for 12 h. Subsequently, presumptive zygotes were transferred into a modified Earle's balanced salt solution (MK-1) supplemented with 4 mg/mL BSA and 50 �g/mL gentamicin. Three days after insemination, all embryos were transferred into culture medium of MK-1 supplemented with 5% (v/v) fetal bovine serum and 50 �g/mL gentamicin. The cleaved embryos were further cultured for 5 days to evaluate their ability to develop to the blastocyst stage. Data were analyzed by ANOVA. The percentages of COCs of A (35.5%, 31.8%, 27.7%), B (41.5%, 39.9%, 42.9%), and C (23.0%, 28.3%, 29.4%) ranks did not show significant differences (P > 0.05) among the reproductive stages of ovaries (luteal, follicular, and inactive, respectively). There were significant differences in the percentages of cleavage (P < 0.05) among the A, B, and C ranks of oocytes from ovaries classified as luteal and follicular stages (50%, 35%, 1.8%; 52%, 35%, 3.9%, respectively, P < 0.05). However, there were no significant differences between the A and B ranks of oocytes obtained from inactive stages of ovaries (47% vs. 44%, respectively; P > 0.05) but there was a significant difference for C rank (1.9%). The percentages of blastocyst formation were significantly different (P < 0.05) among the ranks of oocytes obtained from luteal, follicular, and inactive stages (27%, 14.6%, and 0% for A; 24%, 11.7%, and 0.6% for B; 35%, 21.6%, and 2.9% for C). However, there were no significant differences (P > 0.05) among the reproductive cycle stages of ovaries in the three oocyte ranks with respect to the percentages of cleavage and blastocyst formation.These results indicate that the reproductive stage of donor cat ovaries stored at 4�C for 24 h has no apparent effect on the developmental competence of the oocyte following IVF, but development is affected by oocyte quality.

P–219 mtDNA content in bovine cumulus cells does not predict oocytés developmental competence

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Á Martíne. Moro ◽  
I Lamas-Toranzo ◽  
L González-Brusi ◽  
A Pérez-Gómez ◽  
P Bermejo-Álvarez
Keyword(s):  
Cumulus Cell ◽  
Cumulus Cells ◽  
Oocyte Quality ◽  
Blastocyst Stage ◽  
Early Embryo ◽  
Developmental Competence ◽  
Success Rates ◽  
Developmental Potential ◽  
Mtdna Sequence

Abstract Study question Does cumulus cell mtDNA content correlate with oocyte developmental potential in the bovine model? Summary answer The relative amount of mtDNA content did not vary significantly in oocytes showing different developmental outcomes following IVF What is known already Cumulus cells are closely connected to the oocyte through transzonal projections, serving essential metabolic functions during folliculogenesis. These oocyte-supporting cells are removed and discarded prior to ICSI, thereby constituting an interesting biological material on which to perform molecular analysis aimed to predict oocyte developmental competence. Previous studies have positively associated oocytés mtDNA content with developmental potential in both animal models and women. However, it remains debatable whether mtDNA content in cumulus cells could be used as a proxy to infer oocyte developmental potential. Study design, size, duration Bovine cumulus cells were allocated into three groups according to the developmental potential of the oocyte: 1) oocytes developing to blastocysts following IVF (Bl+Cl+), 2) oocytes cleaving following IVF but arresting their development prior to the blastocyst stage (Bl-Cl+), and 3) oocytes not cleaving following IVF (Bl-Cl-). Relative mtDNA content was analysed in 40 samples/group, each composed by the cumulus cells from one cumulus-oocyte complex (COC). Participants/materials, setting, methods Bovine cumulus-oocyte complexes were obtained from slaughtered cattle and individually matured in vitro (IVM). Following IVM, cumulus cells were removed by hyaluronidase treatment, pelleted, snap frozen in liquid nitrogen and stored at –80 ºC until analysis. Cumulus-free oocytes were fertilized and cultured in vitro individually and development was recorded for each oocyte. Relative mtDNA abundance was determined by qPCR, amplifying a mtDNA sequence (COX1) and a chromosomal sequence (PPIA). Statistical differences were tested by ANOVA. Main results and the role of chance Relative mtDNA abundance did not differ significantly (ANOVA p &gt; 0.05) between the three groups exhibiting different developmental potential (1±0.06 vs. 1.19±0.05 vs. 1.11±0.05, for Bl+Cl+ vs. Bl-Cl+ vs. Bl-Cl-, mean±s.e.m.). Limitations, reasons for caution Experiments were conducted in the bovine model. Although bovine folliculogenesis, monoovulatory ovulation and early embryo development exhibit considerable similarities with that of humans, caution should be taken when extrapolating these data to humans. Wider implications of the findings: The use of molecular markers for oocyte developmental potential in cumulus cells could be used to enhance success rates following single-embryo transfer. Unfortunately, mtDNA in cumulus cells was not found to be a good proxy for oocyte quality. Trial registration number Not applicable

277 FOLLICULAR GROWTH, SUBSEQUENT OVUM PICKUP, AND DOMINANT FOLLICLE REMOVAL IN COWS

2006 ◽  
Vol 18 (2) ◽  
pp. 246
Author(s):  
K. Imai ◽  
M. Tagawa ◽  
S. Matoba ◽  
M. Narita ◽  
K. Kanayama
Keyword(s):  
Formation Rate ◽  
Cumulus Cell ◽  
Oocyte Quality ◽  
Developmental Competence ◽  
Dominant Follicle ◽  
Cleavage Rate ◽  
Significant Difference ◽  
The Mean ◽  
Follicle Aspiration ◽  
Removal Group

The present study was designed to assess the recruitment of follicles after ovum pickup (OPU) and dominant follicle (DF) removal on the follicular wave after OPU in Holstein dry cows. Cows were reared under the same feeding and environmental conditions. In Experiment 1, follicle aspiration (>2 mm in diameter) by OPU using a 7.5-MHz linear transducer with needle (COVA needle; Misawa Medical, Tokyo, Japan) connected to an ultrasound scanner (SSD-1200; ALOKA, Tokyo, Japan) was performed in four cows. Then, ovaries were observed after OPU from Day 1 (Day 0 = the day of OPU) to Day 11 to assess the number of follicles developed. In Experiment 2, two sessions of OPU were performed with a 7 day interval between sessions, with or without dominant follicle removal, to assess the quality of developing follicles and oocytes. In the DF removal group, >8-mm follicles were aspirated at Day 5 after the first OPU session, and the same cows without DF removal were designated as a control (n = 4, crossover trial). Oocytes were evaluated by their cumulus cell morphology, cytoplasmic color, and density. To assess the developmental competence of oocytes, Grades 1 and 2 cumulus-oocyte complexes (COCs) were collected, matured, fertilized, and cultured as described by Imai et al. (2002 J. Vet. Med. Sci. 64(10), 887-891). Embryo development was assessed by the cleavage rate on Day 2 and the blastocyst formation rate on Days 7 to 9 (the day of insemination = Day 0). Data were analyzed by ANOVA or Student t-test. In Experiment 1, a dominant follicle (>8 mm in diameter) was developed during Days 3 to 5 after OPU in each donor. The mean number of developing follicles (>2 mm in diameter) were increased from Day 1 to Day 9 (Day 1: 7.5 � 2.1, Day 3: 19.0 � 1.2, Day 5: 23.3 � 9.0, Day 7: 30.3 � 11.0, Day 9: 42.0 � 15.8 and Day 11: 41.0 � 16.7 (mean � SD), P < 0.05). In Experiment 2, there was no difference in the mean number of developing follicles on the day of OPU and collected oocytes between DF removal and control groups (follicles: 47.8 � 23.0 and 39.3 � 6.2; oocytes: 27.0 � 11.6 and 26.5 � 5.4, respectively). The number of Grades 1 and 2 oocytes for the DF removal group was significantly higher (P < 0.05) than that for the control (83.6 � 1.5 and 63.2 � 14.2, respectively), and no significant difference was found within cleavage (60.0 � 37.2, 53.6 � 23.2) and blastocyst rates (34.1 � 33.9, 34.4 � 16.8). These results indicate that populations of follicles were increased till Day 9 after OPU, and the DF removal was effective at increasing oocyte quality in the developing follicles.

205 CUMULUS CELL MORPHOLOGY BEFORE AND AFTER IN VITRO MATURATION AS AN INDICATOR OF PORCINE OOCYTE DEVELOPMENTAL COMPETENCE

2010 ◽  
Vol 22 (1) ◽  
pp. 260
Author(s):  
M. Bertoldo ◽  
P. K. Holyoake ◽  
G. Evans ◽  
C. G. Grupen
Keyword(s):  
Cell Morphology ◽  
In Vitro Maturation ◽  
Cumulus Cell ◽  
Cumulus Cells ◽  
Oocyte Quality ◽  
Developmental Competence ◽  
Oocyte Developmental Competence ◽  
Before And After ◽  
Follicle Size

Effective in vitro maturation (IVM) is essential for successful in vitro embryo production. The morphology of the cumulus investment before and after IVM may be a useful noninvasive indicator of oocyte quality. In pigs, oocyte developmental competence is reduced during the summer months. The aim of this study was to determine whether the morphology of cumulus-oocyte complexes (COC) before and after IVM are associated with oocyte quality, using COC collected from small and large follicles in summer and winter as models of poor and good oocyte quality. Ovaries were collected from sows slaughtered 4 days after weaning. The COC recovered from small (3-4 mm) and large (5-8 mm) antral follicles were morphologically graded and parthenogenetically activated following IVM during winter (n = 1419; 10 replicates) and summer (n = 2803; 10 replicates). Grade 1 and 2 COC had >2 layers of compact cumulus cells and a homogenous cytoplasm. Grade 3 COC were either partially or fully denuded, had a heterogeneous cytoplasm, or were vacuolated or dark in color. Grade 4 COC had expanded cumulus cells. Cumulus expansion was also assessed subsequent to IVM. The COC recorded as having a cumulus expansion index (CEI) of 1 had the poorest expansion with no detectable response to IVM, whereas those with a CEI of 4 had the greatest amount of expansion, including that of the corona radiata. Data were analyzed using a generalized linear mixed model in GenStat® (release 10, VSN International, Hemel Hempstead, UK). There was an effect of follicle size for Grade 1 COC, with COC from large follicles in both seasons yielding better quality COC (P < 0.05). The proportion of COC in Grade 2 was higher in small follicles during winter compared with large follicles, but there were no differences between follicle sizes during summer (P < 0.05). The proportion of COC with CEI 1 was highest in COC from small follicles during summer (P < 0.05). The proportion of COC from large follicles with CEI 2 was higher during summer compared with winter (P < 0.05). There were no seasonal or follicle size effects on COC with CEI 3 or 4 (P > 0.05). The proportion of oocytes that developed to blastocysts was greater in winter than in summer (39.06% ± 5.67 v. 22.27% ± 4.01; P < 0.05). Oocytes derived from large follicles had a greater ability to form blastocysts compared with those from small follicles (37.13% ± 5.65 v. 23.32% ± 4.56; P < 0.06). Morphological assessment of cumulus cells before and after IVM may be a useful tool to evaluate the effects of follicle size on oocyte developmental competence. However, the results of the present study indicate that cumulus cell morphology is not a good indicator of the effect of season on oocyte developmental competence.

scholarly journals The Role of MAPK3/1 and AKT in the Acquisition of High Meiotic and Developmental Competence of Porcine Oocytes Cultured In Vitro in FLI Medium

2021 ◽  
Vol 22 (20) ◽  
pp. 11148
Author(s):  
Radek Procházka ◽  
Alexandra Bartková ◽  
Lucie Němcová ◽  
Matej Murín ◽  
Ahmed Gad ◽  
...  
Keyword(s):  
Time Course ◽  
Cumulus Cell ◽  
Cell Communication ◽  
Oocyte Quality ◽  
Developmental Competence ◽  
Control Medium ◽  
Developmental Potential ◽  
Akt Activation ◽  
Expression Of Genes

The developmental potential of porcine oocytes cultured in vitro was remarkably enhanced in a medium containing FGF2, LIF and IGF1 (FLI) when compared to a medium supplemented with gonadotropins and EGF (control). We analyzed the molecular background of the enhanced oocyte quality by comparing the time course of MAPK3/1 and AKT activation, and the expression of genes controlled by these kinases in cumulus-oocyte complexes (COCs) cultured in FLI and the control medium. The pattern of MAPK3/1 activation in COCs was very similar in both media, except for a robust increase in MAPK3/1 phosphorylation during the first hour of culture in the FLI medium. The COCs cultured in the FLI medium exhibited significantly higher activity of AKT than in the control medium from the beginning up to 16 h of culture; afterwards a deregulation of AKT activity occurred in the FLI medium, which was not observed in the control medium. The expression of cumulus cell genes controlled by both kinases was also modulated in the FLI medium, and in particular the genes related to cumulus-expansion, signaling, apoptosis, antioxidants, cell-to-cell communication, proliferation, and translation were significantly overexpressed. Collectively, these data indicate that both MAPK3/1 and AKT are implicated in the enhanced quality of oocytes cultured in FLI medium.

scholarly journals 274SIMILARITY OF EMBRYOS PRODUCED BY OVUM PICK-UP AND IN VITRO FERTILIZATION IN IDENTICAL TWIN CATTLE

2004 ◽  
Vol 16 (2) ◽  
pp. 257 ◽  
Author(s):  
K. Imai ◽  
S. Kobayashi ◽  
S. Matoba ◽  
M. Tagawa ◽  
N. Saito
Keyword(s):  
Calf Serum ◽  
Cumulus Cell ◽  
Follicular Development ◽  
Subsequent Development ◽  
Oocyte Quality ◽  
Identical Twin ◽  
Cleavage Rate ◽  
Vitro Fertilization ◽  
Significant Difference

The present study was designed to assess the similarity of follicular development, oocyte quality, and their subsequent development on ovum pick-up (OPU)-IVF in identical twin cattle. Four pairs of identical twin Japanese black cows (A, B pairs at 5 years old and C, D pairs at 3 years old) were kept under the same feeding and environmental conditions. OPU was performed for these cows once a week for seven continuous weeks. OPU was done by using a 7.5-MHz linear transducer with needle (17 G, 530-mm length) connected to an ultrasound scanner (SSD-1200, ALOKA, Tokyo, Japan). Oocytes were evaluated by their cumulus cell morphology, cytoplasmic color, and density. To assess the development, collected COCs were cultured for 20h in TCM-199 supplemented with 5% calf serum (CS) in a microdroplet (volume was adjusted to 5μL/oocyte) at 38.5°C under atmosphere of 5% CO2 in air. After maturation, the COCs were inseminated with frozen-thawed semen collected from the same ejaculation of a single bull. The fertilization was performed with BO solution as described by Imai et al (J. Vet. Med. Sci., 2002, 64(10), 887–891). The zygotes were then cultured in CR1aa supplemented with 5% CS under the same condition of maturation for nine days. Embryo development was assessed by the cleavage rate on Day 2 and the blastocyst production rate on Days 7 to 9 (insemination day=Day 0). Blastocysts were classified according to the IETS creteria. Data were analyzed by ANOVA. A total 56 sessions of OPU were performed in this study. The overall mean number of developing follicles (larger than 2mm in diameter), collected oocytes, and produced blastocysts were 30.3±9.2, 20.1±9.2 and 6.3±3.8 (mean±SD) per session, respectively. The mean number of developing follicles on the day of OPU were significantly different between B and D pairs (38.6±7.5 and 21.9±6.5, P&lt;0.01); however, no significant difference was found within each twin. In oocyte quality, C and D pairs were significantly higher grade than the A pair. The percentages of cleaved oocytes and embryos developed to the blastocyst stage (34±16, 27±10, 41±17 and 39±24) showed no differences among 4 pairs and within each twin. However, the percentage of Grade 1 blastocyst of B pair was significantly lower (P&lt;0.01) than that of other pairs, and C pair was significantly higher (P&lt;0.05) than that of A and D pairs (67±25, 41±22, 93±10 and 71±25; A, B, C and D pairs, respectively). There was no significant difference within twins. These results show little statistical variation between cows of the same genetic background in the production of embryos in vitro.

170 INFLUENCE OF OOCYTE QUALITY AND DIFFERENT MEDIA SUPPLEMENT ON IN VITRO MATURATION, CLEAVAGE, AND EMBRYO DEVELOPMENT OF BUFFALO (BUBALUS BUBALIS) OOCYTES

2014 ◽  
Vol 26 (1) ◽  
pp. 199
Author(s):  
M. M. Waheed ◽  
K. H. El-Shahat ◽  
A. M. Hammam
Keyword(s):  
Embryo Development ◽  
In Vitro Maturation ◽  
Cumulus Cell ◽  
Oocyte Quality ◽  
Bubalus Bubalis ◽  
Poor Quality ◽  
Developmental Competence ◽  
Control Group ◽  
Excellent Quality

A series of 4 factorial-arranged experiments were conducted to study the effect of oocyte quality and different in vitro maturation (IVM) media supplements on IVM, cleavage, and embryo development of buffalo (Bubalus bubalis) oocytes. Buffalo ovaries were collected at a local abattoir in a warm (32–35°C) saline (0.9% NaCl), and oocytes were aspirated using an 18-gauge needle. In experiment 1, oocytes (n = 320) were classified according to the number of cumulus cell layers and morphology of ooplasm as excellent, good, or fair. Oocytes were cultured for IVM, fertilization, and embryo culture (IVMFC) in TCM-199 + 10% FCS. In experiment 2, excellent quality oocytes (n = 237) were subjected to IVM in TCM-199 enriched with either 10% FCS or oestrous buffalo serum (EBS; 20–40 pg mL–1) and then fertilized using frozen–thawed buffalo semen capacitated in Bracket and Oliphant's (BO) medium containing heparin (0.02 mg mL–1) and sodium caffeine benzoate (3.89 mg mL–1). In experiment 3, oocytes (n = 290) were classified into 2 groups; Group 1, without gonadotropins, served as a control; Group 2, in which IVM medium was supplemented with 20 IU mL–1 equine chorionic gonadotropins (eCG). Experiment 4 was carried out to examine the suitable capacitating agent added to BO medium, either heparin or caffeine or both (n = 210 fertilized oocytes). In all experiments (multiple replicates), oocytes (2–6 mm in diameter) were kept at 39°C under 5% CO2 for IVMFC and examined several times for cleavage and embryo development (morula and blastocyst). Statistical analysis was carried out using Chi-squared test. Excellent and good quality oocytes produced a higher (P < 0.05) maturation, cleavage, and morula development rates than poor quality oocytes (70% and 65% v. 33.3%), (50% and 46.2% v. 25%), and (42.9% and 33.3% v. 10%), respectively. Blastocyst production rate was also higher (P < 0.05) for excellent compared with good quality oocytes (28.6% v. 16.7%, respectively). In experiment 2, the IVM and cleavage rates were significantly higher (P < 0.05) in IVM medium plus 10% EBS than those cultured in 10% FCS (73% v. 45% and 50% v. 33.3%, respectively). In experiment 3, the addition of eCG to maturation medium increased (P < 0.05) developmental competence of buffalo oocytes (IVMFC) compared with control medium (16% v. 4%). In experiment 4, the addition of heparin together with caffeine to BO medium produced significantly higher (P < 0.05) cleavage and embryo developmental rates compared with heparin or caffeine alone (56.3% v. 33.3% and 35.7%, respectively; 22.2% v. 10% and 8%, respectively). In conclusion, excellent quality oocytes cultured in IVM medium supplemented with either EBS or eCG and fertilized with capacitated buffalo spermatozoa in BO medium enriched with heparin and caffeine progressively enhanced developmental competence of buffalo oocytes.

scholarly journals Cellular and Molecular Events that Occur in the Oocyte during Prolonged Ovarian Storage in Sheep

Animals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2414
Author(s):  
Alicia Martín-Maestro ◽  
Irene Sánchez-Ajofrín ◽  
Carolina Maside ◽  
Patricia Peris-Frau ◽  
Daniela-Alejandra Medina-Chávez ◽  
...  
Keyword(s):  
Dna Fragmentation ◽  
Saline Solution ◽  
Cumulus Cell ◽  
Small Ruminants ◽  
Oocyte Quality ◽  
Developmental Competence ◽  
Developmental Potential ◽  
Oocyte Competence ◽  
Cell Parameters

For the past two decades, there has been a growing interest in the application of in vitro embryo production (IVP) in small ruminants such as sheep. To improve efficiency, a large number abattoir-derived ovaries must be used, and long distances from the laboratory are usually inevitable when adult animals are used. In that scenario, prolonged sheep ovary transportation may negatively affect oocyte developmental competence. Here, we evaluated the effect of ovary storage time (3, 5, 7, 9, 11 and 13 h) and the medium in which they were transported (TCM199 and saline solution) on oocyte quality. Thus, live/dead status, early apoptosis, DNA fragmentation, reduced glutathione (GSH) and reactive oxygen species (ROS) content, caspase-3 activity, mitochondrial membrane potential and distribution, and relative abundance of mRNA transcript levels were assessed in oocytes. After in vitro maturation (IVM), cumulus cell viability and quality, meiotic and fertilization competence, embryo rates and blastocyst quality were also evaluated. The results revealed that, after 7 h of storage, oocyte quality and developmental potential were significantly impaired since higher rates of dead oocytes and DNA fragmentation and lower rates of viable, matured and fertilized oocytes were observed. The percentage of cleavage, blastocyst rates and cumulus cell parameters (viability, active mitochondria and GSH/ROS ratio) were also decreased. Moreover, the preservation of ovaries in medium TCM199 had a detrimental effect on cumulus cells and oocyte competence. In conclusion, ovary transport times up to 5 h in saline solution are the most adequate storage conditions to maintain oocyte quality as well as developmental capacity in sheep. A strategy to rescue the poor developmental potential of stored oocytes will be necessary for successful production of high-quality embryos when longer ovarian preservation times are necessary.

Neither gonadotropin nor cumulus cell expansion is needed for the maturation of competent porcine oocytes in vitro

2021 ◽  
Author(s):  
Bethany K Redel ◽  
Lee D Spate ◽  
Ye Yuan ◽  
Clifton N Murphy ◽  
R Michael Roberts ◽  
...  
Keyword(s):  
Assisted Reproductive Technologies ◽  
Cumulus Cell ◽  
Reproductive Technologies ◽  
Oocyte Quality ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Oocyte Competence ◽  
Key Indicator ◽  
Cytoplasmic Competence

Abstract In vitro maturation of oocytes from immature females is widely used in assisted reproductive technologies. Here we illustrate that cumulus cell (CC) expansion, once considered a key indicator of oocyte quality, is not needed for oocytes to mature to the metaphase II (MII) stage and to gain nuclear and cytoplasmic competence to produce offspring. Juvenile pig oocytes were matured in four different media: 1) Basal (−gonadotropins (GN)-FLI); 2) -GN + FLI (supplement of FGF2, LIF, and IGF1); 3) + GN-FLI; 4) + GN + FLI. There was no difference in maturation to MII or progression to the blastocyst stage after fertilization of oocytes that had been matured in -GN + FLI medium and oocytes matured in +GN + FLI medium. Only slight CC expansion occurred in the two media lacking GN compared to the two where GN was present. The cumulus-oocytes-complexes (COC) matured in +GN + FLI exhibited the greatest expansion. We conclude that FLI has a dual role. It is directly responsible for oocyte competence, a process where GN are not required, and, when GN are present, it has a downstream role in enhancing CC expansion. Our study also shows that elevated phosphorylated MAPK may not be a necessary correlate of oocyte maturation and that the greater utilization of glucose by COC observed in +GN + FLI medium probably plays a more significant role to meet the biosynthetic needs of the CC to expand than to attain oocyte developmental competence. Gene expression analyses have not been informative in providing a mechanism to explain how FLI medium enhances oocyte competence without promoting CC expansion.

scholarly journals Overcoming poor in vitro nuclear maturation and developmental competence of domestic cat oocytes during the non-breeding season

Reproduction ◽  
2003 ◽  
pp. 809-816 ◽  
Author(s):  
P Comizzoli ◽  
DE Wildt ◽  
BS Pukazhenthi
Keyword(s):  
Ascorbic Acid ◽  
In Vitro Culture ◽  
Breeding Season ◽  
Oocyte Quality ◽  
Fertilization Success ◽  
Domestic Cat ◽  
Developmental Competence ◽  
Ovarian Activity ◽  
Nuclear Maturation

The domestic cat experiences circannual variations in ovarian activity and intrafollicular oocyte quality. One result is poor nuclear and cytoplasmic maturation during in vitro maturation (IVM) conducted during the annual non-breeding season (July through November). In an attempt to overcome this seasonal phenomenon immature oocytes were collected from July through November and cultured in a conventional IVM medium (IVM1) or in IVM1 supplemented with different FSH concentrations and antioxidant (ascorbic acid or cysteine). Nuclear status of oocytes was assessed after IVM or IVF. Embryo stage and blastocyst quality were evaluated after 7 days of in vitro culture. Although the addition of antioxidant alone had no effect, the presence of 10 microg FSH ml(-1) improved nuclear maturation (75.4+/-4.1% versus 48.7+/-8.8% in IVM1; P<0.05) and fertilization success (47.9+/-3.2% versus 35.0+/-5.1% in IVM1; P<0.05). Furthermore, developmental competence of fertilized oocytes was enhanced (P<0.05) only in the presence of ascorbic acid (30.6+/-6.7%) or cysteine (33.6+/-5.1%) compared with IVM1 (8.1+/-8.8%). Consequently, blastocyst yield (17% of total oocytes cultured) was highest when oocytes were matured in medium containing higher FSH concentration and antioxidants. The results of this study demonstrate that meiotic and developmental competences are inherent to the immature cat oocyte collected during the non-breeding season. However, appropriate mechanisms (perhaps seasonal variation in FSH receptors or lack of antioxidant capacity of the cumulus-oocyte complex) are inadequate during this period of gonadal quiescence. Regardless, this compromised oocyte function during the non-breeding season can be overridden by altering in vitro culture conditions to include supplemental FSH and antioxidant.

scholarly journals hCG Priming Before Ovary Collection Increasing The Oocyte Quality In The Domestic Cat

2021 ◽  
pp. 123-126
Author(s):  
Karisma Mardatillah ◽  
Rini Widyastuti ◽  
Diah Nugrahani Pristihadi ◽  
Wahyudin ◽  
Sigit Prastowo ◽  
...  
Keyword(s):  
Oocyte Quality ◽  
Domestic Cat ◽  
Developmental Competence ◽  
Control Group ◽  
Oocyte Competence ◽  
Slicing Method ◽  
Determining Factor

Oocyte competence is a determining factor that influences the embryo development. Embryos produced in vitro have a reduced developmental competence than embryos produced in vivo. Therefore, human Chorionic Gonadotropin (hCG) injection was carried out to improve the quality of the oocytes. The objective of this study was to evaluate the effect of ovarian stimulation with hCG before ovary collection on oocyte quality in the domestic cat. Oocyte donors were either 1) treated with a single dose of 200 IU hCG four days before ovary collection (hCG group), or, 2) no treatment before ovary collection (control group). The oocytes were collected by the slicing method. Immature cumulus oophorus complexes (COCs) from both groups were pooled and matured in vitro for 24-26 hours. Then mature oocytes were fertilized with epididymal sperm and cultured in vitro for seven days. The results study showed that the number of the dominant follicle (DF) and the number of COCs in the hCG group was higher than the control group in right and left ovaries (p<0.05). The morulae and blastocyst rates from cleavage embryos were 88% and 75%, respectively. These results demonstrate that hCG priming of oocytes donors before ovary collection improve oocyte quality.

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