180 EXPRESSION OF CANDIDATE GENES FOR OOCYTE COMPETENCE IN BOVINE CUMULUS CELLS

2009 ◽  
Vol 21 (1) ◽  
pp. 189 ◽  
Author(s):  
E. S. Caixeta ◽  
P. R. Figueiredo ◽  
G. M. Machado ◽  
M. M. Franco ◽  
J. Buratini ◽  
...  

Cumulus cells (CC) are closed connected to the oocytes through a gap junction network during follicular development and ovulation. This reciprocal functional interconnection is essential for oocyte growth, acquitision of competence, and complete maturation. Therefore, CC are a promising source of markers for predicting oocyte developmental potential without damaging the oocyte. There is a clear relationship between follicular size and oocyte competence, being those obtained from large follicles more developmentally competent in vitro. The aim of this study was to identify in CC genes candidates to be involved in the acquisition of competence, using the follicles size model to recovered cumulus–ooctye complexes (COCs) with various levels of competence. Follicles from slaughterhouse ovaries were dissected, selected, and distributed according to their diameter into 4 groups: (1) 1.0 to 3.0 mm, (2) 3.1 to 6.0 mm, (3) 6.1 to 8.0 mm, (4) ≥8.1 mm. The COCs were released by follicle rupture, morphologically classified, matured, fertilized, and cultured in vitro or denuded for the recovery of CC. Then, CC were frozen until gene expression analysis. The developmental potential of oocytes was evaluated by cleavage and blastocyst rates at 48 and 168 h post-insemination, respectively. Transcripts for FSH receptor, GH receptor, epidermal growth factor (EGF) receptor, pentraxin 3, and insulin-like growth factor II (IGF-II) were quantified by real-time RT-PCR and normalized by cyclophilin expression. Data from cleavage and blastocyst rates were analyzed by chi-square test. The relative abundance of mRNA for the 5 genes in CC were evaluated by ANOVA and Tukey’s test. Non-parametric test (Wilcoxon) was used when data were not normally distributed. The results are presented as mean ± SEM, and P < 0.05 was considered statistically different. Cleavage and blastocyst rates were higher in oocytes originated from groups 3 (86 and 62%) and 4 (87 and 60%) than those obtained from groups 1 (20%) and 2 (34%). The lowest level of expression for FSH receptor was observed in CC from 1.0–3.0 mm follicles (1.1 ± 0.07) and the greatest in CC from ≥8.1-mm follicles (2.1 ± 0.09), whereas the expression in the intermediary groups 2 (1.6 ± 0.1) and 3 (1.6 ± 0.2) did not show any difference from the other groups. Similar pattern of expression was observed for EFG receptor gene, except that CC from group 3 (1.7 ± 0.2) already presented a significant increase in mRNA level compared to group 1 (0.9 ± 0.1). Relative abundance of transcript for GH receptor rose gradually in CC according to follicular size, being the higher expression detected in the largest follicles and the lower in the smallest follicles, with means of 0.8 ± 0.1, 2.3 ± 0.6, 2.7 ± 0.6, and 3.9 ± 0.1 for groups 1, 2, 3, and 4, respectively. The other 2 candidates (pentraxin 3 and IGF-II) did not show any significant differences related to follicle size. The results indicate that increases in expression of receptor for FSH, EGF, and GH was coincident with the increase in follicle size and in oocyte developmental potential; therefore, they can be used as markers for bovine oocyte competence. However, additional studies are needed to confirm the markers identified. Financial support from EMBRAPA/CAPES.

2009 ◽  
Vol 21 (5) ◽  
pp. 655 ◽  
Author(s):  
Ester Siqueira Caixeta ◽  
Paula Ripamonte ◽  
Maurício Machaim Franco ◽  
José Buratini Junior ◽  
Margot Alves Nunes Dode

To identify the genes related to oocyte competence, we quantified transcripts for candidate genes in oocytes (H1Foo, H2A, H3A, GHR, GDF9, BMP15, OOSP1) and cumulus cells (FSHR, EGFR, GHR, PTX3, IGFII) using the follicle size model to select oocytes of better developmental quality. Follicles were dissected and distributed into four groups according to diameter as follows: 1.0–3.0, 3.1–6.0, 6.1–8.0 and ≥8.1 mm. Cumulus–oocyte complexes (COCs) were released, classified morphologically, matured, fertilised and cultured in vitro or denuded for measurement of diameter and determination of gene expression. Denuded germinal vesicle oocytes and their cumulus cells were used for gene expression analysis by reverse transcription–polymerase chain reaction. The blastocyst rate was highest for oocytes recovered from follicles >6 mm in diameter. In the oocyte, expression of the H2A transcript only increased gradually according to follicle size, being greater (P < 0.05) in oocytes from follicles ≥8.1 mm in diameter than in oocytes from follicles <6.0 mm in diameter. In cumulus cells, expression of FSHR, EGFR and GHR mRNA increased with follicular size. In conclusion, we confirmed the importance of H2A for developmental competence and identified important genes in cumulus cells that may be associated with oocyte competence.


1997 ◽  
Vol 57 (2) ◽  
pp. 232-245 ◽  
Author(s):  
Ghylène Goudet ◽  
Jacqueline Bézard ◽  
Guy Duchamp ◽  
Nadine Gérard ◽  
Eric Palmer

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Á Martíne. Moro ◽  
I Lamas-Toranzo ◽  
L González-Brusi ◽  
A Pérez-Gómez ◽  
P Bermejo-Álvarez

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


2004 ◽  
Vol 16 (2) ◽  
pp. 282 ◽  
Author(s):  
Z. Roth ◽  
P.J. Hansen

Sphingosine-1-phosphate (S1P) is a sphingolipid metabolite that can block the sphingomyelin cell-death pathway by suppressing ceramide-induced apoptosis. The present study was performed to test whether S1P protects oocytes from heat shock during in vitro maturation. Cumulus-oocyte complexes obtained by slicing follicles were placed in maturation medium with or without 50nM S1P and cultured at 38.5°C (CON) or 41°C (41C) for the first 12h of maturation. Incubation during the last 10h of maturation (22-h total maturation time), fertilization, and embryonic development were performed at 38.5°C and 5% (v/v) CO2. Blastocyst development was recorded at 8 days post-insemination (dpi) and activity of group II caspases in 8-day blastocysts was determined using a fluoroprobe, PhiPhiLux-G1D2 (OncoImmunin, Gaithersburg, MD, USA). Data were analysed by least-squares ANOVA with the GLM procedure of SAS. Percentage data were subjected to arcsin transformation before analysis. Exposure of oocytes to thermal stress during the first 12h of maturation reduced cleavage rate (P&lt;0.01) and the number of oocytes developing to the blastocyst stage (P&lt;0.04). There was a temperature x S1P interaction for cleavage rate (P&lt;0.03) because S1P blocked effects of thermal stress on cleavage rate. Without S1P, the percentage of oocytes that cleaved by 3 dpi were 83.6±2.7% and 65.8±2.7% for CON and 41C, respectively. In the presence of S1P, percent cleavage was 86.7±2.7% and 83.9±2.7% for CON and 41C, respectively. There was a trend (P=0.06) for a temperature x S1P interaction for percent oocytes developing to blastocyst stage because S1P blocked effects of heat shock on development. Without S1P, the percentages of oocytes that developed to the blastocyst stage were 28.7±3.0% and 15.2±3.0% for CON and 41C, respectively. In the presence of S1P, percent blastocysts were 24.3±3.4% and 23.9±3.0% for CON and 41C, respectively. When development was expressed as percentage of cleaved embryos, however, there were no effects of temperature, S1P, or temperature x S1P on percent development to the blastocyst stage. Blastocyst caspase activity was not affected by temperature or S1P. In summary, exposure to physiologically relevant thermal stress during the first 12h of maturation has a deleterious effect on oocyte competence and this effect can be reduced by S1P. The fact that heat shock reduced the percentage of oocytes but not the percentage of cleaved embryos that became blastocysts suggests that oocytes that survive effects of heat shock and cleave have normal potential to develop to the blastocyst stage. Moreover, since heat shock did not affect caspase activity, it is likely that blastocysts from heat-shocked oocytes have normal developmental potential, at least as determined by caspase activity. Support: BARD FI-330-2002 and USDA Grants 2002-35203-12664 and 2001-52101-11318.


2014 ◽  
Vol 26 (2) ◽  
pp. 337 ◽  
Author(s):  
Satoko Matoba ◽  
Katrin Bender ◽  
Alan G. Fahey ◽  
Solomon Mamo ◽  
Lorraine Brennan ◽  
...  

The follicle is a unique micro-environment within which the oocyte can develop and mature to a fertilisable gamete. The aim of this study was to investigate the ability of a panel of follicular parameters, including intrafollicular steroid and metabolomic profiles and theca, granulosa and cumulus cell candidate gene mRNA abundance, to predict the potential of bovine oocytes to develop to the blastocyst stage in vitro. Individual follicles were dissected from abattoir ovaries, carefully ruptured under a stereomicroscope and the oocyte was recovered and individually processed through in vitro maturation, fertilisation and culture. The mean (± s.e.m.) follicular concentrations of testosterone (62.8 ± 4.8 ng mL–1), progesterone (616.8 ± 31.9 ng mL–1) and oestradiol (14.4 ± 2.4 ng mL–1) were not different (P > 0.05) between oocytes that formed (competent) or failed to form (incompetent) blastocysts. Principal-component analysis of the quantified aqueous metabolites in follicular fluid showed differences between oocytes that formed blastocysts and oocytes that degenerated; l-alanine, glycine and l-glutamate were positively correlated and urea was negatively correlated with blastocyst formation. Follicular fluid associated with competent oocytes was significantly lower in palmitic acid (P = 0.023) and total fatty acids (P = 0.031) and significantly higher in linolenic acid (P = 0.036) than follicular fluid from incompetent oocytes. Significantly higher (P < 0.05) transcript abundance of LHCGR in granulosa cells, ESR1 and VCAN in thecal cells and TNFAIP6 in cumulus cells was associated with competent compared with incompetent oocytes.


2006 ◽  
Vol 18 (2) ◽  
pp. 276
Author(s):  
C.-K. Park ◽  
J.-Y. An ◽  
S.-J. Sa ◽  
H.-T. Cheong ◽  
B.-K. Yang ◽  
...  

Plasminogen activators (PAs) are serine proteases, known to be secreted by a large number of cell type. PAs are reported to play a role in variety of physiologic processes, including fibrinolysis, ovulation, mammary involution, implantation, and fertilization. The present study investigated the effects of cumulus cells and porcine follicular fluid (pFF) on PA activity and oocyte maturation in vitro in the pig. Porcine oocytes were harvested from slaughterhouse ovaries, selected, and matured in modified North Carolina State University-23 (NCSU-23) media. After culture, cumulus-oocyte complexes (COCs) and denuded oocytes (DOs) were separately put into microtubes containing 20 �L of sample buffer [5.0% (w:v) sodium dodecyl sulfate, 20% (v:v) glycerol, and 0.0025% (w:v) bromophenol blue in 0.125 M Tris-HCl buffer] and frozen at -80�C until used for zymographic analysis. Differences in data were evaluated by Duncan's multiple-range test using the General Linear Models procedure in the Statistical Analysis System (SAS Institue, Inc., Cary, NC, USA). To determine the effect of porcine follicular fluid (pFF) on PA activity in porcine oocytes during maturation, the COCs and DOs were incubated in NCSU-23 medium with or without 10% (v/v) pFF for 0, 24, or 48 h. In the presence of cumulus cells, the proportions of oocytes matured to metaphase-II stage were significantly (P < 0.05) higher in medium with pFF than without pFF (69.8% vs. 37.7%, respectively). When COCs and DOs were cultured in the presence of pFF, tissue-type PA (tPA), urokinase-type PA (uPA), and tPA-PA inhibitor (tPA-PAI) were observed in COCs, and PA activities were higher at 48 h than 24 h. However, no PA activity was detected in DOs. Under the same conditions, when COCs and DOs were cultured in the absence of pFF, tPA and tPA-PAI were observed in COCs, and PA activities were increased as duration of culture increased. However, no PA activity was detected in DOs. When porcine oocytes were cultured in the presence of pFF, the activities of tPA-PAI, tPA, and uPA were observed in conditioned medium with COCs and DOs cultured for 24 h and 48 h. In the absence of pFF, PA activities were observed only in conditioned medium with COCs, and no PA activities were detected in conditioned medium with DOs. On the other hand, three plasminogen-dependent lytic bands (tPA-PAI, tPA, and uPA) were observed in pFF cultures. Particularly uPA activity was higher than the other kinds of PA activity. When oocytes and cumulus cells were separated from porcine COCs at 0 h of cultrue, tPA-PAI, tPA, and uPA were detected in cumulus cells at 48-h culture, but no PA activities were in DOs. The presence of pFF and cumulus cells in maturation medium stimulated not only nuclear and cytoplasmic maturation in porcine COCs, but also PA production by cumulus cells and COCs. It is possible that PAs produced by cumulus cells migrated through the gap junction between oocyte and cumulus cells. These results suggest that porcine oocytes have no ability to produce PA themselves.


2006 ◽  
Vol 18 (2) ◽  
pp. 275
Author(s):  
H. S. Lee ◽  
Y. I. Seo ◽  
X. J. Yin ◽  
S. G. Cho ◽  
I. H. Bae ◽  
...  

In spite of our increased knowledge of in vitro oocyte maturation techniques, the success rate of obtaining mature canine oocytes in vitro remains very low compared with that for other domestic animals. The inefficient rate of meiotic resumption of canine oocytes is probably due to both the unique reproductive cycle and inappropriate in vitro maturation (IVM) medium. In an unpublished experiment, we found that the concentration of insulin was higher in estrus bitch serum (EBS; 8833 pg/mL) than in dog follicular fluid (DFF; preovulatory follicle, 122 pg/mL), which implies its possible role in the acquisition of oocyte competence. Therefore, in the present study we investigated the effects of supplementing the IVM medium with insulin on the incidence of maturation to metaphase II. Ovaries were collected from various stages of the estrous cycle by ovariohysterectomy, and oocytes with two or more intact cumulus layers and with a diameter >110 �m were selected and used for IVM. Oocytes were cultured in modified synthetic oviduct fluid (2004 Reprod. Nutr. Dev. 44, 105-109) supplemented with 10% EBS, 20 �g/mL estradiol, and different concentrations of insulin (0, 10, 100, or 1000 ng/mL) at 38.5�C, 5% CO2 in air. After 72 h, cumulus cells were removed from around oocytes using a small glass pipette. Denuded oocytes were fixed in 3.7% paraformaldehyde supplemented with 10 �g/mL Hoechst 33342 at room temperature for 40 min. Nuclear status was observed under UV light using a fluorescence microscope. The percentage of oocytes at the metaphase II stage was not different among the four groups 6.8, 1.8, 5.4, and 2.1% in the control, 10, 100, and 1000 ng/mL insulin groups, respectively. The incidence of oocytes with pronuclear-like structures or cleaving beyond the two-cell stage was not significant higher in the 10 and 100 ng/mL insulin treatment groups than in the control and 1000 ng/mL insulin groups 20.0 and 19.6% vs. 6.8 and 6.4%, respectively. These results indicate that the addition of insulin to the in vitro maturation medium of dog oocytes had no effect on the incidence of meiotic maturation to metaphase II, nor did it affect the frequency of occurrence of spontaneous oocyte activation.


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