194 IN VITRO MATURATION AND RNA CONTENT AND DISTRIBUTION OF PORCINE OOCYTES DERIVED FROM SMALL AND MEDIUM FOLLICLES AND CLASSIFIED BY BRILLIANT CRESYL BLUE ASSAY

2012 ◽  
Vol 24 (1) ◽  
pp. 209 ◽  
Author(s):  
L. T. Ngoc Thanh ◽  
H. Funahashi

Oocytes collected from the surface of slaughterhouse ovaries clearly have heterogeneous quality. The objective was to characterize a change or difference in RNA distribution and the content of porcine oocytes that were collected from small (SF; 1–2 mm in diameter) and medium follicles (MF; 3–6 mm in diameter) and assessed for glucose-6-phosphate dehydrogenase (G6PD) activity by brilliant cresyl blue (BCB) assay. Following BCB staining, porcine cumulus–oocyte complexes (COC) with dark blue (DB; G6PD-inactive, suggesting good quality) and light blue (LB; G6PD-active, suggesting immaturity) ooplasm were then separately cultured in vitro to evaluate nuclear maturation and analyze the characteristics of the RNA aspect. RNA distributions in cumulus cell mass and ooplasm were labeled with fluorescence, SYTO RNA select green and then examined at different periods of culture for in vitro maturation (IVM; with gonadotropins and dbcAMP for 20 h and then without those for 24 h). Total RNA content of oocytes and cumulus cell mass were measured by using a manufacture's kit (Invitrogen Quant-iT RNA assay kit). Statistical analyses of results from 3 to 5 replicated trials were performed by ANOVA with a Bonferroni/Dunn post-hoc test (significance, P < 0.05). When oocytes were classified by BCB assay, the percentage of oocytes with DB cytoplasm was much higher (P < 0.05) in oocytes from MF (72.5% of 208) compared with those of SF (53.6% of 352). Regardless of the origin of oocytes (SF vs MF), the incidence of mature oocytes following culture was higher in DB than LB (64.0% of 147 and 72.1% of 133 vs 50.9% of 108 and 52.8% of 54, respectively). Twenty hours after the start of IVM, the DB oocytes had a higher proportion of RNA-free zone inside the germinal vesicle compared to the LB oocytes (66.1% of 193 and 26.8% of 159 in MF; 47.9% of 185 and 17.9% of 184 in SF; P < 0.05). When the total content of RNA was examined during IVM, both oocytes from SF and MF contained higher levels of total RNA at the beginning of IVM as compared with 20 and 44 h after the start of IVM, whereas the content (40 denuded oocytes/sample) was higher in oocytes with DB cytoplasm from MF than those from SF (P < 0.05). Regardless of the origin of oocytes from SF and MF, the total content of RNA in oocytes with LB cytoplasm was significantly lower than in oocytes with DB cytoplasm (P < 0.05) before the start of IVM. The total RNA content of cumulus cells (40 COC/sample) before IVM culture was also higher in the cell mass surrounding the DB oocytes than the LB ones and in the cell mass surrounding the oocytes from MF rather than SF (P < 0.05). These results demonstrate a possibility that differences in RNA distribution and content in oocytes, as well as the content in cumulus cells, reflect in the ability of porcine oocytes to mature in vitro.

Author(s):  
Arya T. S. ◽  
Amritha Aravind ◽  
Abhilash R. S. ◽  
Jayakumar C. ◽  
Babitha V.

The present study was conducted to assess the developmental competence of goat oocytes selected using Brilliant cresyl blue (BCB) staining. Goat ovaries were collected from the slaughtered animals with unknown reproductive history. The oocytes retrieved by aspiration technique were selected based on morphology and subjected to BCB staining. Brilliant cresyl blue staining is based on the activity of glucose-6-phospahte dehydrogenase (G6PDH) enzyme synthesised by the oocytes. The cytoplasm remains blue in oocytes that have finished the growth phase (BCB+) while the growing oocytes remain colourless (BCB-). The stained and unstained oocytes were subjected to in vitro maturation separately to assess cumulus cell expansion index and polar body extrusion. A total of 206 culture grade oocytes were subjected to study, out of which, 76.75 ± 2.38 per cent of oocytes showed positive to BCB staining and 23.21 ± 2.38 per cent were negatively stained. Significantly higher maturation rate was observed in BCB+(92.89 ± 2.37%) oocytes than BCB-(29.72 ± 2.46%). The present study concluded that BCB staining can be used for selecting goat oocytes with good cytoplasmic maturation for further in vitro embryo production


2021 ◽  
Vol 14 (2) ◽  
pp. 452-456
Author(s):  
Mohamed Fathi ◽  
Amr F. Elkarmoty

Aim: Several factors had been concerned with the developmental competence of the sheep oocyte. This study aims to investigate the effect of adding growth factors (insulin-like growth factor 1 [IGF-1] and epidermal growth factor [EGF]) in the maturation medium of ewe oocytes selected based on brilliant cresyl blue (BCB) screening on in vitro maturation (IVM), fertilization, and pre-implantation embryo development. Materials and Methods: Cumulus-oocyte complexes (COCs) were obtained from the ovaries of slaughtered ewes by either aspiration or slicing techniques. COCs were in vitro matured in a medium containing IGF-1 and EGF (control group). For BCB screening, oocytes were stained and divided into BCB+ oocytes that matured in the same maturation conditions without adding growth factors (Group 2) or in the presence of growth factors (Group 3), and BCB– oocytes that matured in medium without growth factors (Group 4) or with growth factors (Group 5). Results: The supplementation of the maturation medium with growth factors during IVM of (BCB+) oocytes resulted in a significant increase in nuclear maturation rate (90.9%), fertilization rate (75.6%), and embryo developmental rates (60.0%, 46.7%, and 33.3% for cleavage, morula, and blastocyst, respectively). Conclusion: Culturing BCB+ oocytes in a maturation medium containing both EGF and IGF-1 showed a significant improvement in nuclear maturation, fertilization, and pre-implantation embryo development in vitro.


2006 ◽  
Vol 18 (2) ◽  
pp. 270
Author(s):  
C. Hanna ◽  
C. Long ◽  
M. Westhusin ◽  
D. Kraemer

The objectives of this study were to determine whether the percentage of canine oocytes that resume meiosis during in vitro maturation could be increased by either increasing culture duration or by removing approximately one-half of the cumulus cells 24 h after oocytes were placed into culture. Canine female reproductive tracts were collected from a local clinic and ovaries were minced in warm TL-HEPES. Oocytes with a consistently dark ooplasm and at least two layers of cumulus cells were selected, cultured in a basic canine oocyte in vitro maturation medium consisting of TCM-199 with Earl's salts, 2.92 mM Ca-lactate, 20 mM pyruvic acid, 4.43 mM HEPES, 10% fetal calf serum, 1% Penicillin/Streptomycin (GibcoBRL, Grand Island, NY, USA), and 5 μg/mL porcine somatotropin, and incubated at 38.5°C in 5% CO2 in humidified air. Treatment groups were randomly assigned and oocytes were cultured for 60, 84, or 132 h (Basic). From each of these groups, one-half of the oocytes were pipetted through a fine bore pipette to partially remove the cumulus cells 24 h after the start of culture (Basic–1/2). At the end of culture, all oocytes were denuded and the nuclear status was observed with Hoechst 33342 under ultraviolet fluorescence. All data were analyzed by ANOVA with P < 0.05. Since the canine oocyte is ovulated at the germinal vesicle (GV) stage of meiosis and requires up to five days to mature in the oviduct, it was hypothesized that an increased culture time would allow for more oocytes to undergo nuclear maturation to metaphase II (MII). It was also hypothesized that partial removal of cumulus cells would decrease the cumulus cell component in the ooplasm that sustains meiotic arrest, allowing for more oocytes to resume meiosis (RM = germinal vesicle breakdown to MII). Results within each treatment group indicate that there is no significant difference between culture duration and the percent of oocytes that mature to MII. Additionally, there was no significance in the percent of oocytes that resumed meiosis after partial cumulus cell removal. Taken together, these data suggest that neither treatment is effective in canine in vitro maturation systems, given the current maturation culture conditions. Table 1. Nuclear status* of oocytes for three time periods with or without partial cumulus cell removal


2010 ◽  
Vol 22 (1) ◽  
pp. 260
Author(s):  
M. Bertoldo ◽  
P. K. Holyoake ◽  
G. Evans ◽  
C. G. Grupen

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.


2015 ◽  
Vol 27 (1) ◽  
pp. 235
Author(s):  
K. P. M. Lekola ◽  
J. W. Ng'ambi ◽  
N. Nkadimeng ◽  
M. L. Mphaphathi ◽  
T. L. Nedambale

In vitro maturation of indigenous African cattle oocytes is a major challenge even though different maturation protocols work successfully in other breeds. The objective of this study was to determine the maturation rate of indigenous South African cattle oocytes following in vitro maturation in media supplemented with different concentrations of hormones and selected using brilliant cresyl blue (BCB) staining. Indigenous cattle ovaries were collected from the slaughterhouse and then oocytes were retrieved by aspiration method. A total of 966 oocytes were exposed to 26 µM BCB stain and 700 oocytes were not exposed to the BCB stain. Thereafter, oocytes exposed to the BCB stain were grouped according to the colour of their cytoplasm BCB+ (oocytes with blue cytoplasm, low G6PDH) and BCB– (unstained oocytes, increased G6PDH). The BCB exposed (BCB+ and BCB–) and the oocytes not exposed to BCB were then randomly allocated into tissue culture medium (TCM199) + 10% (vol/vol) fetal bovine serum (FBS) supplemented with 3 different concentrations of hormones as treatments (T). The T1 group was matured in the presence of 0.5 µg mL–1 of FSH, 5 mg mL–1 of LH, and 2 µg mL–1 of E2; the T2 group was matured in the presence of 1 µg mL–1 of FSH, 6 mg mL–1 of LH, and 2.5 µg mL–1 of E2; and the T3 group was matured in the presence of 1.5 µg mL–1 of FSH, 7 mg mL–1 of LH, and 4.5 µg mL–1 of E2. For IVM, 20 to 25 COC were placed in 50-µL droplets of IVM medium containing the 3 different levels of hormones. Maturation rate of oocytes was determined by the extrusion of the first polar body after 24 h of incubation in maturation medium. Data was analysed by ANOVA using SAS with 4 replicates per treatment. Treatment 2 yielded higher maturation rate for both BCB+ (65.6%) and not exposed to BCB (60.3%) oocytes compared to T1 (22, 3.03, and 16% for BCB+, BCB–, and not exposed to BCB, respectively) and T3 (48, 2.2, and 48% for BCB+, BCB–, and not exposed to BCB respectively). However, BCB– oocytes had lower polar body extrusion for T1, T2, and T3 (3.03, 8.1, and 2.2%, respectively) compared to BCB+ oocytes (22, 65.6, and 48% for T1, T2, and T3, respectively). In conclusion, immature oocytes that were cultured into TCM199 supplemented with 10% FBS, 1 µg mL–1 of FSH, 6 mg mL–1 of LH, and 2.5 µg mL–1 of E2 showed maturation rate for BCB+ oocytes and those not exposed to BCB. Oocytes selection using BCB staining was a useful test to classify good quality cattle oocytes. Therefore, it is suggested that treatment 2 is a suitable in vitro-maturation medium to mature indigenous South African cattle oocytes.


2010 ◽  
Vol 22 (1) ◽  
pp. 322
Author(s):  
D. D. Bücher ◽  
M. A. Castro ◽  
M. E. Silva ◽  
M. A. Berland ◽  
I. I. Concha ◽  
...  

Granulocyte-macrophage colony stimulating factor (GM-CSF) is a pleiotropic cytokine that stimulates proliferation, differentiation and function in different cells types. We have previously demonstrated (Bücher DD et al. 2008 Reprod. Dom. Anim. 43 (Suppl. 3), 146 abst.) that both subunits of GM-CSF receptor are expressed in granulosa cells from antral follicles in bovine ovaries. Also, we determined that the cytokine enhances glucose uptake through facilitative hexose transporters in granulosa cells in primary culture. The goals of the present study were to characterize the expression of GM-CSF receptor in cumulus cells and oocytes from bovine antral follicles and to determine its effects on in vitro-matured bovine COCs in a chemically defined medium. To determine the presence of a and |5 subunits of GM-CSF receptor, COCs were aspirated from follicles <8 mm in diameter, fixed, and submitted to immunocytochemistry. To study the effect of GM-CSF on in vitro maturation of oocytes, COCs (n =481) were cultured using serum-free medium (SOF) containing 0, 1, 10, and 100 ng mL-1 of human recombinant GM-CSF (R&D Systems, Inc., Minneapolis, MN, USA) for 22 h at 39°C, 5% CO2 in humidified air. Nuclear stage, cumulus expansion, cumulus cell number, and viability were analyzed after in vitro maturation. Cumulus expansion was assessed using the cumulus expansion index (CEI) (Fagbohun C and Down S 1990 Biol. Reprod. 42, 413-423). Nuclear stage was evaluated using aceto-orcein stain. To determine cumulus cell viability and number, COCs (n = 10-12 per group) were transferred into an Eppendorf tube and cumulus cells were removed by vortexing for 3 min, stained with trypan blue and counted with a hemocytometer. The study was conducted in 6 replicates. Data from cumulus expansion and cell number were analyzed by Kruskal-Wallis analysis. Data for nuclear stage and cell viability were analyzed by chi-square analysis and one way ANOVA, respectively. Both receptor subunits were present in cumulus cells and oocytes from COCs. COCs cultured in 10 and 100 ng mL-1 GM-CSF had CEI scores (0.8 and 1.22, respectively) greater (P < 0.01) than controls (0.2), but the proportion of COCs displaying second metaphase did not differ (P = 0.5) among treatment groups. GM-CSF at a concentration of 100 ng mL-1 increased (P < 0.01) cumulus cell viability by more than 20% compared to the control group. Similarly, GM-CSF at concentrations of 10 and 100 ng mL-1 increased (P < 0.05) cumulus cell number by more than 20% and 45%, respectively, from the control group. The use of a specific inhibitor of PI3 kinase (Ly294002; 10 and 100 μM) blocked the stimulatory effect of GM-CSF on cumulus expansion, cell viability, and cell number. In conclusion, the results of the study suggest a plausible modulator role of GM-CSF in the metabolism and function of cumulus cells and oocytes during in vitro maturation. Funding from Faculty of Veterinary Sciences, Universidad Austral de Chile, MECESUP AUS-0005, AUS-0601, and DID D-2006-24 and from Universidad Católica de Temuco, research grant 2007 DGI-CDA-04.


2017 ◽  
Vol 29 (1) ◽  
pp. 202 ◽  
Author(s):  
A. Lange-Consiglio ◽  
C. Perrini ◽  
P. Esposti ◽  
F. Cremonesi

The in vitro maturation of canine oocyte is problematic because it is difficult to reproduce the oviducal microenvironment where the in vivo maturation occurs. Because cells are able to communicate with each other by paracrine action, oviducal cells could be in vitro cultivated to obtain the conditioned medium (CM) consisting of soluble factors and microvesicles (MV), which represent a carrier for nonsoluble molecules including microRNA. The aim of the present work was to investigate the effect of the addition of CM or MV, secreted by oviducal cells, to the canine in vitro maturation medium. To generate CM, cells from oviducts of 3 animals in late oestrus were cultured for 5 days at 38.5°C in a humidified atmosphere of 5% CO2. Supernatants were collected, pooled, centrifuged at 2500 × g, and stored at −80°C. Microvesicles were obtained by ultracentrifugation of CM at 100,000 × g for 1 h at 4°C and measured for concentration and size by a Nanosight instrument. Ovaries were obtained from 50 healthy domestic bitches (1–4 years old) of different breeds that underwent ovariectomy regardless of the oestrous cycle. Cumulus-oocyte complexes were released by slicing the ovarian cortex with a scalpel blade, and only Grade 1 cumulus-oocyte complexes (darkly granulated cytoplasm and surrounded by 3 or more compact cumulus cell layers) 110 to 120 µm in diameter were selected for culture. Maturation was performed at 38.5°C in a humidified atmosphere of 5% CO2 and 5% of O2 in bi-phasic systems: 24 h in SOF with 5.0 μg mL−1 of LH followed by 48 h in SOF supplemented with 10% of oestrous bitch serum and 10% CM or 50, 75, 100, or 150 × 106 MV mL−1 labelled with PKH-26. Control was the same medium without CM or MV. Oocytes were observed under a fluorescent microscope to detect metaphase II (MII), by Hoechst staining, and the incorporation of MV. Statistical analysis was performed by chi-square test. Results show that canine oviducal cells secreted MV of 234 ± 23 nm in size, underling that these MV fall within the shedding vesicles category. The incorporation of labelled MV occurred at first in cumulus cells, at 48 h of maturation, and then, at 72 h, in oocyte cytoplasm. These MV had a positive effect on maturation rate (MII) at the concentration of 75 and 100 × 106 MV mL−1 compared with CM and control (20.34 and 21.82 v. 9.09 and 3.95%, respectively). The concentration of 150 × 106 MV mL−1 provided only 9.26% of MII. To understand the role of MV, we assessed the expression of 3 microRNA (miRNA-30b, miR-375, and miR-503) that are involved in some key pathways (WNT, MAPK, ERbB, and TGFβ) regulating follicular development and meiotic resumption. The lower rate of MII with the higher concentration of MV is possibly due to the high level of miR-375, which recent literature shows to suppress the TGFβ pathway, leading to impaired oocyte maturation. In conclusion, the oviducal MV, or specific microRNA, are involved in cellular trafficking during oocyte maturation, and their possible use in vitro could facilitate the exploitation of canine reproductive biotechnologies.


Zygote ◽  
2019 ◽  
Vol 27 (3) ◽  
pp. 166-172 ◽  
Author(s):  
Linying Jia ◽  
Bo Ding ◽  
Chong Shen ◽  
Shiwei Luo ◽  
Yanru Zhang ◽  
...  

SummaryRabbits play an important role in people’s lives due to their high nutritional value and high-quality hair that can be used as raw material for textiles. Furthermore, rabbits are an important animal model for human disease, as genome-edited animals are particularly valuable for studying gene functions and pathogenesis. Somatic cell nuclear transfer (SCNT) is an important technique for producing genome-edited animals and it has great value in saving endangered species and in clone stem cell therapy. However, the low efficiency of SCNT limits its application, with the selection of suitable rabbit oocytes being crucial to its success. In the present study, we collected oocytes from ovarian follicles and stained them with 26 μM brilliant cresyl blue (BCB). We then matured the oocytes in vitro and used them for SCNT. Comparison of the BCB-positive oocytes with BCB-negative oocytes and the control group showed that the BCB-positive group had a significantly higher maturation rate (81.4% vs. 48.9% and 65.3% for the negative and control groups, respectively), cleavage rate (86.6% vs. 67.9% and 77.9%), blastocyst rate (30.5% vs. 12.8% and 19.6%), total number of blastocysts (90±7.5 vs. 65.3±6.3 and 67.5±5.7), and inner cell mass (ICM)/ trophectoderm (TE) index (42.3±4.2 vs. 30.2±2.1 and 33.9±5.1) (P<0.05). The BCB-positive group had a significantly lower apoptosis index (2.1±0.6 vs. 8.2±0.9 and 6.7±1.1 for the negative and control groups, respectively) (P<0.05). These findings demonstrate that BCB-positive oocytes have a higher maturation ability and developmental competence in vitro, indicating that BCB staining is a reliable method for selecting oocytes to enhance the efficiency of SCNT.


2021 ◽  
Vol 10 (3) ◽  
pp. e15710313074
Author(s):  
Denilsa Pires Fernandes ◽  
Fernanda Araujo dos Santos ◽  
Luã Barbalho de Macêdo ◽  
Roberta Gonçalves Izzo ◽  
Brenna de Sousa Barbosa ◽  
...  

The aim of this study was to evaluate the effect of three different incubation times on in vitro maturation of domestic cat oocytes. Thus, ovaries (n = 42) were submitted to slicing procedure and the oocytes recovered were classified; only good quality oocytes (Grade I and II) underwent in vitro maturation for three different periods (24 vs. 30 vs. 36 h) in supplemented TCM-99 medium. After, oocytes were evaluated for cumulus cell expansion and presence of the first polar body. After six replicates (7 ± 1,7 ovaries per replicate), a total of 334 viable oocytes were recovered. Differences (p <0.05) were observed regarding the percentage of oocytes presenting expansion of the cumulus cells, where higher values were observed in the group of oocytes incubated for 36 h (84.3%), when compared to 30 (73.4%) and 24 h (71.0%). Moreover, differences were also observed regarding the presence of the first polar body (24 h: 29.7%; 30 h: 58.2%; 36 h: 69.8%). We conclude that the incubation period influenced the maturation rates, indicating 36 h as the ideal period for the in vitro maturation of domestic cat oocytes in supplemented TCM-199 medium.


Author(s):  
Adek Amansyah

Objective: To evaluate the relationship between the number of LH receptor and the success of oocyte maturity in the process of in vitro maturation (IVM). Method: This experimental study was conducted in the Permata Hati Infertility Clinical Laboratory, Dr. Sardjito General Hospital, Yogyakarta, with the samples of 300 oocytes obtained through collecting immature cow’s oocytes from the abattoir and grouped the oocytes into 3 (three) groups based on the pattern of oocyte cumulus cells on the vesicle germinal stage 2 - 8 mm with three layers of cumulus cell. The sample of the cumulus cells from these three groups were taken and the LH receptor examination was done with immunohistochemistry. After that, the IVM process was performed to the three groups and its development for 24 hours was evaluated. Its maturation quality was evaluated with the emergence of the first polar body (1PB) and compared to the other groups and related to the number of LH receptor in the three groups. Result: The result of this study indicated that the oocyte cumulus cells showed a difference of function during IVM process. The maturity rate in this study showed that the number of LH receptor was related to the morphological pattern of oocyte cumulus cells with oocyte maturity. The maturity of the cumulus cells which 100% covered the oocyte was higher than that of the cumulus cells which > 50% and < 30% covered the oocytes, namely, 74% compared to 60% and 12%. The result of this study also showed that the average number of LH receptors in the three groups (A, B, and C) was 183.4, 78.8, and 24.0 respectively. A significant difference was found in the three groups (p < 0.0001). When related to IVM maturity, this difference showed that the bigger number of oocyte cumulus cells influenced the oocyte maturity. Conclusion: The number of LH receptor can be used as a prediction to determine the success of oocyte maturation in the process of in vitro maturation. [Indones J Obstet Gynecol 2013; 1-4:183-7] Keywords: IVM, LH receptor, oocyte cumulus cell


Sign in / Sign up

Export Citation Format

Share Document