209 MATURATION KINETICS AFTER HOLDING EQUINE OOCYTES IN EMBRYO HOLDING MEDIUM

2016 ◽  
Vol 28 (2) ◽  
pp. 235
Author(s):  
P. Dini ◽  
O. Bogado ◽  
K. Smits ◽  
A. VanSoom ◽  
P. Daels
Keyword(s):  
In Vitro Maturation ◽  
Polar Body ◽  
Developmental Competence ◽  
Hoechst 33342 ◽  
Immature Oocytes ◽  
Maturation Rate ◽  
Chromatin Configuration ◽  
One Way Anova ◽  
Selection Of

It has been reported that immature, equine oocytes can be maintained in meiotic arrest at 24°C. To evaluate a commercial equine embryo holding medium for storage of equine oocyte at 24°C and to determine the effect of holding on maturation kinetics, cumulus‐oocyte complexes (COC) were recovered from slaughtered mares and placed in Syngro® Embryo Holding Solution at 22–25°C for 18–20 h (OH Group) or placed directly in DMEM-F12-based in vitro maturation (IVM) conditions (D-Mat Group) at 5% CO2 in air at 38.5°C. Maturation rate (metaphase II percentage; MII%) was assessed (presence of polar body under stereomicroscope) after denudation at 22, 24, and 28 h. After assessment, the denuded oocytes that were considered immature were placed back in IVM, reassessed at 24 and 28 h, and MII% was compared with that of oocytes remaining uninterrupted in IVM for 24 and 28 h. One-way ANOVA was used to compare dependent variable in different groups using PROC ANOVA (SAS, version 9.2, SAS Institute, Cary, NC, USA). A random selection of mature oocytes from both groups were fertilised using intracytoplasmic sperm injection (ICSI). A total of 250 injected oocytes were cultured in DMEM-F12 with 10% FCS. Blastocyst rates in OH and D-mat groups were similar (7.1% v. 6.3%). At 22 h, significantly more oocytes reached the MII stage in the OH group than in the D-Mat group, but MII% was similar in both groups at 24 and 28 h (Table 1). Denuded, immature oocytes reached similar maturation rate as the undenuded oocytes in the same group. Our data suggest that oocytes can be held in Syngro® Embryo Holding Solution at 22–25°C for 18–20 h without compromising oocyte developmental competence. Overnight holding of oocytes accelerates maturation with similar maturation rate at 22, 24, and 28 h of IVM in the OH group. Denudation of immature oocytes after 22 h of IVM and returning the denuded oocytes to IVM does not affect the progression of maturation. In subsequent experiment, overnight held oocytes were fixed and stained (Hoechst 33342) and MII% was evaluated after 20, 22, and 28 h of IVM. Chromatin configuration confirmed that stored oocytes reach the MII stage at 22 h. Maturation rates were significantly lower at 20 h, suggesting that 22 h of IVM is required for stored oocytes. Table 1.Maturation rates (% in MII stage) at 22, 24, and 28 h of IVM for equine oocytes held in Syngro® Embryo Holding Medium before IVM (OH) and oocytes placed directly in IVM (D-Mat) Thanks to I. Lemahieu and P. Van Damme. Study was supported by the Special Research Fund at UGent.

scholarly journals Effects of various concentrations of gonadotropins and 17β estradiol on the in vitro maturation of cattle oocytes selected using brilliant cresyl blue staining

1970 ◽  
Vol 46 (3) ◽  
pp. 321-326
Author(s):  
K.P.M. Lekola ◽  
J.W. Ng’ambi ◽  
M. Nkadimeng ◽  
M.L. Mphaphathi ◽  
T.L. Nedambale
Keyword(s):  
In Vitro Maturation ◽  
Polar Body ◽  
Blue Staining ◽  
Brilliant Cresyl Blue ◽  
Immature Oocytes ◽  
Cresyl Blue ◽  
Polar Bodies ◽  
First Polar Body ◽  
Maturation Rate

The objective of this study was to determine the in vitro maturation rate of cattle oocytes selected with brilliant cresyl blue (BCB) stain, in tissue culture medium 199 (TCM 199) supplemented with various concentrations of hormones. Oocytes were retrieved from abattoir-derived ovaries by aspiration. Oocytes were then exposed to 26 μM BCB stain, and classified according to the colour of their cytoplasm: BCB+ (oocytes with blue cytoplasm) and BCB- (unstained oocytes). The BCB selected and the non-selected immature oocytes were randomly allocated into TCM 199 + 10% foetal bovine serum (FBS) maturation media supplemented with three concentrations of hormones as treatments (T). The T1 group was matured in the presence of 0.5 μg follicle stimulating hormone (FSH)/mL, 5 mg luteinising hormone (LH)/mL and 2 μg estradiol (E2)/mL. The T2 group was matured in 1 μg FSH, 6 mg LH and 2.5 μg E2/mL. The T3 group was matured in 1.5 μg FSH, 7 mg LH and 4.5 μg E2/mL. The maturation rate of oocytes was determined by the protrusion of the first polar bodies 24 h after maturation. Data were analysed by ANOVA using SAS. Treatment 2 yielded higher maturation rates for with BCB+ (30.5%) and without BCB (35%) oocytes, with T1 giving a lower maturation rate for BCB+ (10.7%) and without BCB (9.7%) oocytes. However, BCB- oocytes had lower polar body extrusion (0.7%, 1% and 2.7%) for T1, T2 and T3, respectively. In conclusion, immature oocytes that were exposed to BCB+ and cultured in TCM 199 supplemented with 10% FBS, 1 μg FSH, 6 mg LH and 2.5 μg E2/mL had a higher number of matured oocytes (extrusion of first polar body), similar to those that were not exposed to BCB (no BCB). Oocyte selection with BCB staining was a useful test for classifying good-quality cattle oocytes.

scholarly journals In vitro maturation of goat oocytes selected using Brilliant cresyl blue staining

2021 ◽  
Vol 52 (4) ◽  
Author(s):  
Arya T. S. ◽  
Amritha Aravind ◽  
Abhilash R. S. ◽  
Jayakumar C. ◽  
Babitha V.
Keyword(s):  
In Vitro Maturation ◽  
Polar Body ◽  
Cumulus Cell ◽  
Developmental Competence ◽  
Blue Staining ◽  
Brilliant Cresyl Blue ◽  
Cresyl Blue ◽  
Maturation Rate ◽  
Polar Body Extrusion

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

129 DEVELOPMENTAL COMPETENCE OF PORCINE OOCYTES AFTER IN VITRO MATURATION AND IN VITRO CULTURE UNDER COMPARATIVE OXYGEN TENSION

2011 ◽  
Vol 23 (1) ◽  
pp. 169
Author(s):  
J. T. Kang ◽  
M. Atikuzzaman ◽  
D. K. Kwon ◽  
S. J. Park ◽  
S. J. Kim ◽  
...  
Keyword(s):  
In Vitro Culture ◽  
Oxygen Tension ◽  
Embryo Development ◽  
In Vitro Maturation ◽  
Polar Body ◽  
Mrna Abundance ◽  
Developmental Competence ◽  
Multiple Genes ◽  
Oxygen Concentrations

The in vitro developmental abilities of porcine oocytes are generally increasing steadily at a similar ratio to those of in vivo embryos. However, it has been suggested that the in vitro culture system for the development of porcine embryos is not optimal. In this study, we investigated the effect of 2 oxygen concentrations (5 and 20%) on porcine embryo development during in vitro maturation and in vitro culture and analyzed differences in gene expression of resulting blastocysts. Oocytes were recovered by aspiration of slaughterhouse ovaries and then matured in tissue culture medium (TCM) 199 supplemented with 10% porcine follicular fluid (pFF), epidermal growth factor (EGF), insulin, pyruvate, cystine, and gonadotropin. Matured oocytes were then activated parthenogenetically, cultured in PZM-3 media for 7 days. In vitro maturation (M group) of oocytes was carried out under two oxygen concentration (5 and 20%) in terms of nuclear maturation (polar body extrusion; Exp. 1). The developmental differences between 5% oxygen culture group and 20% oxygen culture group during in vitro culture (C group) of embryos after parthenogenetic activation was investigated in terms of first cleavage and blastocyst formation (Exp. 2). Relative mRNA abundance of multiple genes in blastocysts was analyzed for transcript abundance of genes related with metabolism (GLUT1, LDHA), oxidative response (MnSOD, GPX1), apoptosis (BAX, Bcl2), and developmental competence (CCNB1, IGF2R; Exp. 3). The results show there were no significant differences in maturation rate between 2 oxygen concentrations during in vitro maturation (83 v. 86%). It was thought that cumulus cells surrounding oocytes might have attenuated oxidative stress, but number of resulting blastocysts were (P < 0.05) increased in 5% IVC group when compared with 20% IVC group (18.67 v. 14.09%, respectively). Moreover, the M20C5 group (23.01%) had a beneficial effect on in vitro culture compared with M5C5 (14.32%), M5C20 (10.30%), and M20C20 (17.88%) groups. Total cell numbers were not significantly different among groups. According to mRNA abundance data of multiple genes, each group altered the expression of genes in various patterns. Therefore, it could be concluded that high oxygen tension during in vitro maturation and low oxygen tension during in vitro culture might alter the expression of multiple genes related to oocyte competence and improve (P < 0.05) embryo development, but not blastocyst quality. This study was supported by MKE (#2009-67-10033839, #2009-67-10033805), NRF (#M10625030005-508-10N25), BK21 for Veterinary Science, IPET (#109023-05-1-CG000), and Hanhwa L&C.

293 EFFECT OF DIFFERENT CONCENTRATIONS OF LH, FSH, AND E2 ON THE MATURATIONAL RATE OF INDIGENOUS SOUTH AFRICAN CATTLE OOCYTES SELECTED BY BRILLIANT CRESYL BLUE STAINING

2015 ◽  
Vol 27 (1) ◽  
pp. 235
Author(s):  
K. P. M. Lekola ◽  
J. W. Ng'ambi ◽  
N. Nkadimeng ◽  
M. L. Mphaphathi ◽  
T. L. Nedambale
Keyword(s):  
South African ◽  
In Vitro Maturation ◽  
Polar Body ◽  
Blue Staining ◽  
Brilliant Cresyl Blue ◽  
Cresyl Blue ◽  
African Cattle ◽  
Maturation Medium ◽  
Maturation Rate

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.

176 Effect of epigallocatechin-3-gallate on bovine oocyte in vitro maturation, fertilization, and development

2019 ◽  
Vol 31 (1) ◽  
pp. 212
Author(s):  
Y. Honkawa ◽  
Y. Gen ◽  
S.-H. Hyon ◽  
C. Kubota
Keyword(s):  
Oocyte Maturation ◽  
In Vitro Maturation ◽  
Polar Body ◽  
Sperm Concentration ◽  
P Value ◽  
Bovine Oocyte ◽  
Vitro Fertilization ◽  
Significant Difference ◽  
Maturation Rate

Epigallocatechin-3-gallate (EGCG) is a major ingredient of catechin polyphenols, and a strong antioxidant compound. Huang et al. (2018 Asian-australas. J. Anim. Sci.) reported that adding 50μM EGCG can improve the bovine oocyte maturation rate. In this research, we investigated the effect of EGCG supplementation on different periods in bovine IVF. Cumulus-oocyte complex (COC) collected from ovaries of slaughtered cows were cultured in maturation medium (20 to 30 oocytes per 100-µL droplet), which consisted of TCM-199 with Earle’s salts and 25mM HEPES supplemented with 10% (vol/vol) fetal bovine serum (FBS), 1µg mL−1 oestradiol, 0.02mg mL−1 FSH, and antibiotics at 38.5°C in a humidified atmosphere of 5% CO2 in air for 24h (in vitro maturation, IVM). After IVM, COC were fertilized in the fertilization medium (modified Brackett-Oliphant media supplemented with 10 µgmL−1 heparin, 10mM caffeine, and 3mg mL−1 BSA) for 6h using semen of one bull at final sperm concentration of 1×107 mL−1 (IVF). After IVF, COC were denuded and cultured in culture medium [CR1aa supplemented with 10% (vol/vol) FBS and antibiotics] at 38.5°C in a humidified atmosphere of 5% O2, 5% CO2, and 90%N2 for 8 days (in vitro culture, IVC). The EGCG was supplemented at 10, 25, 50, and 100M in IVM medium; 25 and 50 µM in IVF medium; and 50 and 100 µM in IVC medium. After 24h in IVM medium, COC were denuded by pipetting, fixed in 3:1 ethanol:acetic acid for 24h and then checked for nuclear and polar body by using aceto-orcein stain. After 18h in IVF, the pronucleus in zygote was fixed in 3:1 ethanol:acetic acid for 24h and checked by aceto-orcein staining. Embryo development was evaluated by counting the total number of embryos that had reached compacted morula by 6 to 8 days after IVF. Significant differences were analysed by chi-squared test and residual analysis. A P-value&lt;0.05 was considered statistically significant. When EGCG was added to IVM, there was no significant difference of oocyte maturation rate between all concentrations (0v. 10v. 25v. 50v. 100 μM: 73.9% v. 56.7% v. 76.7% v. 72.7% v. 63.5%). When EGCG was added to IVF, there was no significant difference of fertilized rate (0v. 25v. 50 μM: 59.4% v. 73.7% v. 64.9%). When EGCG was added to IVC, there was no significant difference in development rate (0v. 50v. 100 μM: 26.2% v. 15.7% v. 22.0%). In this research, EGCG addition did not affect bovine in vitro fertilization.

167 DEVELOPMENTAL COMPETENCE OF PORCINE OOCYTES DERIVED FROM SMALL- OR MEDIUM-SIZED FOLLICLES AND DENUDED OF CUMULUS CELLS BEFORE AND DURING IN VITRO MATURATION

2017 ◽  
Vol 29 (1) ◽  
pp. 192
Author(s):  
P. Ferré ◽  
K. X. Nguyen ◽  
T. Wakai ◽  
H. Funahashi
Keyword(s):  
Oocyte Maturation ◽  
In Vitro Maturation ◽  
Polar Body ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Cumulus Cells ◽  
Developmental Competence ◽  
Blastocyst Formation ◽  
First Polar Body

This experiment was undertaken to assess the meiotic and developmental competences of oocytes derived from different sized follicles and denuded of cumulus cells 0, 20, and 44 h after the start of culture for in vitro maturation (IVM). Groups of 60 oocyte-cumulus complexes from small- (SF; <3 mm) and medium-sized follicles (MF; 3–6 mm) were cultured for IVM in porcine oocyte medium with 50 μM β-mercaptoethanol supplemented with 1 mM dibutyryl-cyclic adenosine monophosphate, 10 IU mL−1 of eCG, and 10 IU mL−1 of hCG for 20 h at 39°C and 5% CO2 in air. Then, after washing, they continued culture in fresh β-mercaptoethanol without dibutyryl-cyclic adenosine monophosphate and gonadotropins under the same conditions for another 24 h. At 0, 20, and 44 h of IVM, cumulus cells were removed with 0.1% (wt/vol) hyaluronidase and the denuded oocytes continued IVM culture following the protocol. Mature oocytes with the first polar body were selected, parthenogenetically activated with a single electrical pulse (DC: 1.2 kV/cm, 30 µs), incubated with 4% (wt/vol) BSA and 5 μM cytochalasin B for 4 h, and cultured in porcine zygote medium for 5 days. Cleavage and blastocyst formation rates were observed on Day 2 and 5, respectively. Blastocysts were stained with 4’,6-diamidino-2-phenylindole for cell count assessment. The experiment was replicated 5 times and analysed with a 1- or 2-way ANOVA. If P < 0.05 in ANOVA, a Tukey multiple comparisons test was performed. Regardless of the time of cumulus cell removal, oocytes from MF had significantly higher in rates of maturation, cleavage, and blastocyst rates, as compared with those from SF, whereas there were no significant differences in the cell number of blastocysts between SF and MF (32 v. 34 cells, respectively). When oocytes were denuded before IVM culture, rates of oocyte maturation (37.6% in SF and 50.8% in MF), and blastocyst formation (2.7% in SF and 27.3% in MF) were significantly lower than controls (51.2% in SF and 76% in MF; 25.8% in SF and 48.5% in MF, respectively). When oocytes were denuded 20 h after the start of IVM, oocyte maturation rates were significantly increased (64.1% in SF and 82.5% in MF) as compared with controls, whereas no significant differences were observed in cleavage and blastocyst formation rates in comparison with controls. These results conclude that removing cumulus cells from oocyte-cumulus complexes 20 h after the start of IVM improves the meiotic competence of oocytes derived from both SF and MF, without any reduction of developmental competence of the oocytes following parthenogenetical activation.

scholarly journals DETERMINATION OF AN EFFECTIVE MEDIA AND ITS HORMONE AND PROTEIN SUPPLEMENNTATION FOR IN VITRO MATURATION OF OOCYTES OF INDIGENOUS ZEBU COWS

2018 ◽  
Vol 16 (1) ◽  
pp. 45-51
Author(s):  
M. M. Rahman ◽  
S. N. M. Morshed ◽  
N. S. Juyeana ◽  
M. M. U. Bhuyian
Keyword(s):  
Bovine Serum ◽  
In Vitro Maturation ◽  
Mammalian Species ◽  
Polar Body ◽  
Protein Supplementation ◽  
Basic Medium ◽  
First Polar Body ◽  
Maturation Rate ◽  
Zebu Cows

In vitro maturation (IVM) of oocytes is the first important step for successful in vitro embryo production of any mammalian species. The objectives of the present study were to determine an effective basic medium and its hormone and protein supplementation for IVM of oocytes of indigenous zebu cows. The oocytes were derived from ovaries of locally slaughtered cows after aspiration of follicle. The oocytes were cultured in medium for 24 hrs at 38.5ºC with 5% CO2 in humidified air for maturation. The maturation of oocytes was evaluated by examining the presence of first polar body extrusion in denuded oocytes under inverted microscope. To determine an effective basic medium, the oocytes were cultured in fetal bovine serum (FBS) supplemented tissue culture medium (TCM), modified synthetic oviduct fluid (mSOF) and Tyrodes albumin lactate pyruvate (TALP) medium. The maturation rate was significantly higher (74±4.2) in TCM medium than that of TALP medium (58.2±6.2). To determine an effective hormone supplementation for maturation medium, the oocytes were cultured in either in follicle stimulating hormone (FSH) or gonadotrophin supplemented TCM. The maturation rate of oocytes was significantly (p>0.05) higher (73.3±4.0) in FSH supplemented medium than that of gonadotrophin supplemented counterpart (60.2±6.6). To determine an effective protein supplementation, the oocytes were cultured in FBS, oestrus cow serum (OCS) and bovine serum albumin (BSA) supplemented TCM 199. The maturation rate of oocytes were 73.0±5.9, 71.1±2.8, and 62.5±9.4 in medium supplemented with FBS, OCS and BSA respectively (p>0.05). In conclusions, TCM supplemented with either FBS, OCS or BSA as protein and FSH as hormone may be used as medium for IVM of oocytes of indigenous zebu cows.

scholarly journals Does the Apoptosis Value of Cumulus Cells Play a Role in Rescue Oocyte in Vitro Maturation?

2020 ◽  
pp. 1
Author(s):  
Tulay Irez ◽  
Sinem Ercan Dogan ◽  
Enver Ciraci ◽  
Saadet Busra Aksoyer ◽  
Muhammet Sait Toprak ◽  
...  
Keyword(s):  
Experimental Study ◽  
Luteinizing Hormone ◽  
Embryo Development ◽  
In Vitro Maturation ◽  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Immature Oocytes ◽  
Maturation Rate

<p><strong>OBJECTIVE:</strong> In this study, we aimed to investigate the role of the cumulus cell’s apoptosis parameter in the maturation of immature rescue oocytes. </p><p><strong>STUDY DESIGN:</strong> In this experimental study, donated immature germinal vesicle oocytes were cultured for, in vitro maturation, embryo development in matured germinal vesicle oocytes were compared with apoptotic properties of cumulus cells. </p><p><strong>RESULTS:</strong> In all of the immature oocytes after oocyte in vitro maturation, the maturation rate has been observed as 56.1% and 2PN rate as 63.0%. Afterin vitro maturation of germinal vesicle oocytes, there was no difference in apoptosis rates of the cumulus cells between mature and immature oocytes (p&gt; 0.05). The ratio of 2PN in matured germinal vesicle oocytes showing embryo development was 35.4%. A positive correlation was found between luteinizing hormone values on day 3 and E2 values during HCG days during oocyte maturation and embryo development (p=0.021, p=0.020). In addition, it has been observed that the germinal vesicle oocytes, which have completed their maturation and developed into embryos, have high E2 values during HCG days (p=0.020).</p><p><strong>CONCLUSION:</strong> In our study, it has been demonstrated that in vitro maturation in rescue oocytes from stimulated cycles, embryo development potential could not be explained by the apoptosis parameter.</p>

scholarly journals 303 EFFECT OF SERUM SUPPLEMENTATION AND ESTRUS CYCLE STAGE ON IN VITRO NUCLEAR MATURATION OF CANINE OOCYTES

2005 ◽  
Vol 17 (2) ◽  
pp. 302
Author(s):  
F.Y. Heru ◽  
H.J. Oh ◽  
M.K. Kim ◽  
J. Goo ◽  
M.S. Hossein ◽  
...  
Keyword(s):  
Luteal Phase ◽  
In Vitro Maturation ◽  
Germinal Vesicle ◽  
Follicular Phase ◽  
Estrus Cycle ◽  
Immature Oocytes ◽  
Nuclear Maturation ◽  
Serum Supplementation ◽  
Maturation Rate

The present study investigated the effects of the estrus cycle stage and serum supplementation on nuclear maturation of canine oocytes. Ovaries were collected from a private clinic after ovariohysterectomy and classified into follicular, luteal, or anestrus stages through a combination of ovarian morphology and vaginal cytology. A total of 2214 oocytes from 196 ovaries (903 oocytes from 96 anestrus ovaries, 609 oocytes from 36 follicular ovaries, and 702 oocytes from 64 luteal ovaries) were used for experiments. The oocyte retrieval per ovary was 10, 19, and 12 for anestrus, follicular and luteal-phase ovaries, respectively. In Exp. 1, immature oocytes were cultured for 72 h in TCM-199 alone or TCM-199 supplemented with 10% canine anestrus (CAS), estrus (CES), or diestrus (CDS) serum or fetal bovine serum (FBS). In Exp. 2, immature oocytes were cultured for 72 h in TCM-199 supplemented with 0, 5, 10, or 20% CES. After staining with Hoechst 33342, chromatin state and position as well as spindle formation were evaluated to determine the stage of meiosis: germinal vesicle (GV) stage, germinal vesicle breakdown (GVBD), metaphase I (MI) stage, metaphase II (MII) stage. The experiments with anestrus and luteal-phase oocytes were repeated eight times and follicular-phase oocytes were repeated six times. Data were subjected to analysis of variance (ANOVA) and protected least significant difference (LSD) test to determine differences among experimental groups by using the Statistical Analysis System (SAS, SAS Institute, Inc., Cary, NC, USA) program. Statistical significance was determined where P value was less than 0.05. In Exp. 1, the in vitro maturation of oocytes up to MII stage was higher when oocytes were collected from ovaries in follicular phase. The maturation rate up to MII stage was 0.0 to 1.7%, 1.3 to 10.2%, and 1.0 to 3.2% for the oocytes collected from the anestrus, follicular, and luteal-phase ovaries, respectively, depending on the culture media used. In basic TCM media only, 0.0, 1.3, and 2.3% oocytes reached the MII stage for anestrus, follicular, and luteal-phase oocytes, respectively. A significantly higher rate of maturation was obtained when oocytes collected from follicular phase were cultured in TCM-199 supplemented with 10% CES (10.2%), compared to 10% CAS (4.0%), CDS (2.7%), FBS (1.3%), or the control (1.3%). In Exp. 2, supplementing with 10% CES induced the highest (P < 0.05) maturation rate to the MII stage in oocytes collected from follicular-stage ovaries (11.5%) compared to supplementing with 0% (1.0%), 5% (1.3%), or 20% CES (5.1%). Supplementing with CES (5, 10, or 20%) did not have a significant effect on nuclear maturation of canine oocytes collected from anestrus or luteal-stage ovaries. In conclusion, supplementing in vitro maturation medium with 10% CES increased nuclear maturation of canine oocytes, and canine oocytes collected from follicular-stage ovaries are the most suitable to complete nuclear maturation in vitro. This study was supported by grants from the Biogreen 21-1000520030100000.

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