Bovine oocyte developmental competence and gene expression following co-culturing with ampullary cells: An experimental study

Background: There is no sufficient information on the impact of bovine ampullary oviductal epithelial cells (BAOECs) on in vitro oocyte maturation competence and gene expression. Objective: This study aimed to examine the oocyte developmental competence following co-culturing with a monolayer of fresh and frozen-thawed ampullary cells. Materials and Methods: Bovine cumulus-oocyte complexes (COCs) were distributed into three groups: control group; where in COCs were cultured in cell-free media for 24 hr and FML and FTML groups in which the COCs were cultured in maturation media for 18 hr and then transferred into a media containing fresh and frozen-thawed BAOECs monolayer, respectively (BAOECs were extracted from the oviducts of slaughtered cattle and were then cultured freshly or frozen-thawed) for a further 6 hr. After 24 hr, the expanded COCs were evaluated for nuclear maturation, fertilization rate, and gene expression (GDF9, StAR, CASP3, and FSHr). Results: Nuclear maturation rate in the FTML group was significantly higher than the control group (p = 0.02). The fertilization rate of FTML group was significantly higher than the control and FML groups (p = 0.05 and p = 0.03, respectively). In terms of gene expression, GDF9 were upregulated in the presence of the BAOECs during the last 6 hr of the in vitro maturation (p < 0.001). Furthermore, the expression of the StAR gene in the FTML group was higher than the other groups (p = 0.02). Conclusion: Ampullary cells co-culturing (especially frozen-thawed cells) for in vitro maturation of bovine oocytes yields encourages the results and demonstrates the beneficial effect of co-culture on gene expression and developmental competence. Key words: Ampulla, Bovine, Fertilization, Gene expression, IVM.

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Porcine follicular fluid derived from > 8 mm sized follicles improves oocyte maturation and embryo development during in vitro maturation of pigs

Zygote ◽

10.1017/s0967199420000398 ◽

2020 ◽

pp. 1-6

Author(s):

Ji-Eun Park ◽

Sang-Hee Lee ◽

Yong Hwangbo ◽

Choon-Keun Park

Keyword(s):

Embryonic Development ◽

Follicular Fluid ◽

In Vitro Maturation ◽

Developmental Competence ◽

Control Group ◽

Cumulus Expansion ◽

Treatment Groups ◽

Nuclear Maturation ◽

Cytoplasmic Maturation

Summary The aim of the present study was to investigate the effects of porcine follicular fluid (pFF) from large-sized (LFF; >8 mm in diameter) and medium-sized (MFF; 3–6 mm in diameter) follicles on the maturation and developmental competence of porcine oocytes. Cumulus–oocyte complexes (COCs) were collected from follicles 3–6 mm in diameter. The collected COCs were incubated for 22 h with LFF or MFF (in vitro maturation (IVM)-I stage) and were incubated subsequently for 22 h with LFF or MFF (IVM-II stage). Cumulus expansion was confirmed after the IVM-I stage and nuclear maturation was evaluated after the IVM-II stage. Intracellular glutathione (GSH) and reactive oxygen species (ROS) levels were measured and embryonic development was evaluated. Relative cumulus expansion and GSH levels were higher in the LFF group compared with in the MFF group after the IVM-I stage (P < 0.05). After the IVM-II stage, the numbers of oocytes in metaphase-II were increased in the LFF group and GSH content was higher in all of the LFF treatment groups compared with in the MFF treatment groups during both IVM stages (P < 0.05). ROS levels were reduced by LFF treatment regardless of IVM stage (P < 0.05). Blastocyst formation and the total numbers of cells in blastocysts were increased in all LFF treatment groups compared with the control group (P < 0.05). These results suggested that pFF from large follicles at the IVM stage could improve nucleic and cytoplasmic maturation status and further embryonic development through reducing ROS levels and enhancing responsiveness to gonadotropins.

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313 PRE-IN VITRO MATURATION WITH CYCLIC AMP AND CYCLIC GMP MODULATORS IMPROVES DEVELOPMENTAL COMPETENCE OF MOUSE OOCYTES

Reproduction Fertility and Development ◽

10.1071/rdv27n1ab313 ◽

2015 ◽

Vol 27 (1) ◽

pp. 245 ◽

Cited By ~ 1

Author(s):

N. W. Santiquet ◽

A. F. Greene ◽

W. B. Schoolcraft ◽

R. L. Krisher

Keyword(s):

Embryo Development ◽

In Vitro Maturation ◽

Subsequent Development ◽

Developmental Competence ◽

Nuclear Maturation ◽

Oocyte Developmental Competence ◽

Oocyte Collection ◽

Short Period

In vitro maturation (IVM) of cumulus-oocyte complexes (COC) results in oocytes with reduced quality and is still not as efficient as in vivo maturation in most species. One hypothesis that could explain the low developmental competence of oocytes following IVM is that the oocytes resume meiosis too quickly after being retrieved from the follicles. Studies in mice and bovine have shown that a short period of prematuration in the presence of cAMP modulators, before IVM, enhances oocyte developmental competence. Moreover, other studies have recently demonstrated that cGMP is also a crucial molecule involved in meiotic resumption. Here, our objective was to examine the effect of a cGMP modulator in combination with a cAMP modulator during a short period of prematuration on mouse oocyte nuclear maturation and subsequent embryo development following IVF. The COC were collected (6 replicates) from 2-month-old outbred CF1 mice 48 h after PMSG (5 IU) injection in the presence (pre-IVM) or absence (control) of cGMP and cAMP modulators. Pre-IVM COC (n = 184) were then placed in prematuration medium that also contained these cGMP and cAMP modulators. After 2 h, pre-IVM COC were washed and transferred to our in-house prepared, completely defined IVM medium (Paczkowski et al. 2014 Reprod.) for the remaining 16 h of culture; 10 oocytes per 50 µL drop under oil, at 37°C in 7.5% CO2 and 6.5% O2 due to the increased altitude at our location. Control COC (n = 161) were matured in the same IVM medium under identical conditions for 18 h, without prematuration. After IVM, oocytes were fixed for assessment of nuclear maturation, or fertilized and cultured in vitro and subsequent development (96 and 112 h) was recorded (Paczkowski et al. 2014 Reprod.). Results were analysed by ANOVA. A short 2-h prematuration period in the presence of cGMP and cAMP modulators had no impact on oocyte nuclear maturation to metaphase II after IVM or on embryo cleavage after IVF. However, pre-IVM treatment improved the developmental competence of the oocyte, as demonstrated by increased embryo development. More (P < 0.02) blastocysts (96 h of culture) and hatched blastocysts (112 h of culture) developed in the pre-IVM treatment compared to control (31.0 ± 3.4 v. 19.9 ± 3.2%; 31.5 ± 3.4 v. 19.9 ± 3.2%, respectively). In conclusion, a combination of cGMP and cAMP modulators during oocyte collection and a subsequent short pre-IVM improves oocyte developmental competence and could therefore be a potential tool to improve embryo yield following IVM.

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Effect of Interleukin-7 on In Vitro Maturation of Porcine Cumulus-Oocyte Complexes and Subsequent Developmental Potential after Parthenogenetic Activation

Animals ◽

10.3390/ani11030741 ◽

2021 ◽

Vol 11 (3) ◽

pp. 741

Author(s):

Dongjin Oh ◽

Joohyeong Lee ◽

Eunhye Kim ◽

Seon-Ung Hwang ◽

Junchul-David Yoon ◽

...

Keyword(s):

Mrna Expression ◽

Oocyte Maturation ◽

In Vitro Maturation ◽

Developmental Competence ◽

Control Group ◽

Developmental Potential ◽

Parthenogenetic Activation ◽

Nuclear Maturation ◽

Interleukin 7

Interleukin-7 (IL-7) is a cytokine essential for cell development, proliferation and survival. However, its role in oocyte maturation is largely unknown. To investigate the effects of IL-7 on the in vitro maturation (IVM) of porcine oocytes, we analyzed nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels, and subsequent embryonic developmental competence after parthenogenetic activation (PA) under several concentrations of IL-7. After IVM, IL-7 treated groups showed significantly higher nuclear maturation and significantly decreased intracellular ROS levels compared with the control group. All IL-7 treatment groups exhibited significantly increased intracellular GSH levels compared with the control group. All oocytes matured with IL-7 treatment during IVM exhibited significantly higher cleavage and blastocyst formation rates after PA than the non-treatment group. Furthermore, significantly higher mRNA expression levels of developmental-related genes (PCNA, Filia, and NPM2) and antioxidant-related genes (GSR and PRDX1) were observed in the IL-7-supplemented oocytes than in the control group. IL-7-supplemented cumulus cells showed significantly higher mRNA expression of the anti-apoptotic gene BCL2L1 and mitochondria-related genes (TFAM and NOX4), and lower transcript levels of the apoptosis related-gene, Caspase3, than the control group. Collectively, the present study suggests that IL-7 supplementation during porcine IVM improves oocyte maturation and the developmental potential of porcine embryos after PA.

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39 THE EFFECTS OF RESVERATROL DURING IN VITRO MATURATION ON THE DEVELOPMENTAL COMPETENCE OF PORCINE OOCYTES VITRIFIED AT THE IMMATURE STAGE

Reproduction Fertility and Development ◽

10.1071/rdv29n1ab39 ◽

2017 ◽

Vol 29 (1) ◽

pp. 127 ◽

Cited By ~ 1

Author(s):

E. C. S. Santos ◽

T. Somfai ◽

R. Appeltant ◽

T. Q. Dang-Nguyen ◽

H. Kaneko ◽

...

Keyword(s):

In Vitro Maturation ◽

Polar Body ◽

Developmental Rate ◽

Immature Stage ◽

Developmental Competence ◽

Control Group ◽

Dibutyryl Camp ◽

Cleavage Rate ◽

Nuclear Maturation

Previously, live offspring have been produced from porcine oocytes vitrified at the immature stage (Somfai et al. 2014 PLoS One 9, e97731); however, their embryo developmental rates remain low. The aim of our current research was to test the effects of resveratrol, an antioxidant and anti-apoptotic agent on the developmental competence of immature vitrified oocytes during in vitro maturation (IVM) after warming. Follicular porcine cumulus-oocyte complexes (COC) were vitrified on Cryotop® sheets (Kitazato Corp. Shizuoka, Japan) using the cryoprotectant treatment and warming method of Somfai et al. (2015 J. Reprod. Dev. 61, 571–579). After warming, the oocytes were subjected to IVM for 46 h in a chemically defined porcine oocyte medium (POM) enriched with 10 ng mL−1 epidermal growth factor, 10 IU mL−1 eCG, and 10 IU mL−1 hCG. During the first 22 h of IVM, the medium was supplemented with 1 mM dibutyryl cAMP. The following 24 h of IVM was performed in POM without dibutyryl cAMP. Vitrified/warmed COC (vitrified group) and freshly collected COC (control group) were matured either in the absence or presence of 2 µM resveratrol (RES− and RES+, respectively) throughout the entire IVM. At the end of IVM, oocytes were denuded and their survival was evaluated. Then, those with 1 polar body (PB1+) were selected for parthenogenetic activation (Day 0). Activated oocytes were cultured for 7 days in PZM-3. Survival, nuclear maturation, cleavage, and blastocyst rates were assessed. The experiment was replicated 5 times. Results were analysed by one-way ANOVA and Tukey’s multiple comparison test. Vitrification reduced the percentage of live oocytes after IVM both in RES− and RES+ groups in a similar manner (47.9 and 51.8%, respectively) compared with control RES− and RES+ groups (99.4 and 100%, respectively; P < 0.05) There was no statistical difference among groups in the percentage of PB1+ oocytes (ranging between 76.1 and 90.2%). On Day 2, the cleavage rate in vitrified RES− group was lower than those in control RES− and RES+ groups (55.9 v. 78.5% and 79.2%, respectively) whereas the vitrified RES+ group did not differ from the others (72.1%). The blastocyst developmental rate calculated from total cultured oocytes on Day 7 in vitrified RES+ group was significantly higher (P < 0.05) than that in the vitrified RES− group (26.2% v. 6.9%, respectively) and did not differ significantly from those of control RES− and RES+ groups (32.1 and 36.0%, respectively). Blastocyst rates in control RES− and RES+ groups were significantly higher (P < 0.05) than that in vitrified RES− group but did not differ from one another. In conclusion, supplementation of IVM medium with resveratrol improved the developmental competence of vitrified, but not freshly collected oocytes. This work was supported by JSPS KAKENHI (Grant Number: 26870839) and JST/JICA SATREPS. E.C.S. Santos was supported by a CNPq-Brasil fellowship.

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189 THE EFFECTS OF RESVERATROL ON PORCINE OOCYTES IN VITRO MATURATION AND SUBSEQUENT DEVELOPMENT AFTER PARTHENOGENETIC ACTIVATION AND IN VITRO FERTILIZATION

Reproduction Fertility and Development ◽

10.1071/rdv24n1ab189 ◽

2012 ◽

Vol 24 (1) ◽

pp. 207 ◽

Cited By ~ 1

Author(s):

S. S. Kwak ◽

S. A. Jeong ◽

Y. B. Jeon ◽

S. H. Hyun

Keyword(s):

Gene Expression ◽

Embryonic Development ◽

In Vitro Maturation ◽

Formation Rate ◽

Control Group ◽

Developmental Potential ◽

Parthenogenetic Activation ◽

Nuclear Maturation ◽

Significant Difference

The present study investigated the effects of resveratrol (a phytoalexin with various pharmacological activities) during in vitro maturation (IVM) of porcine oocytes on nuclear maturation, intracellular glutathione (GSH) and reactive oxygen species (ROS) levels, gene expression in matured oocytes and subsequent embryonic development after parthenogenetic activation (PA) and IVF. Data were analyzed with SPSS 17.0 using Duncan's multiple range test. In experiment 1, a total of 1146 cumulus–oocyte complexes (COC) were divided into 5 groups (0, 0.1, 0.5, 2.0 and 10.0 μM resveratrol). In the nuclear maturation after 44-h IVM, the groups of 0.1, 0.5 and 2.0 μM (83.0, 84.1 and 88.3%, respectively) had no significant difference compared to the control group (84.1%). The group of 10.0 μM decreased the nuclear maturation (75.0%) significantly (P < 0.05). In experiment 2, a total of 300 matured oocytes were examined for the effects of different resveratrol concentrations (0, 0.5, 2.0 and 10.0 μM) on porcine oocyte intracellular GSH and ROS levels. The groups of 0.5 and 2.0 μM showed a significant (P < 0.05) increase in intracellular GSH levels (1.3 and 1.3, respectively) compared with the control and 10.0 μM groups (1.0 and 1.0, respectively). The intracellular ROS level of oocytes matured with 2.0 μM resveratrol (0.4) was significantly (P < 0.05) decreased compared to other groups (control: 1.0; 0.5 μM: 0.6; and 10.0 μM: 0.7). In experiment 3, lower expression of apoptosis-related genes (Bax, Caspase-3 and Bak) was observed in matured oocytes treated with 2.0 μM resveratrol when compared with that of the control (P < 0.05). In experiment 4, a total of 728 oocytes were divided into 4 groups (control, 0.5, 2.0 and 10.0 μM) and examined subsequent to embryonic development after PA. Oocytes treated with 2.0 μM resveratrol during IVM had a significantly higher cleavage (CL) rate, blastocyst (BL) formation rate and total cell numbers (TCN) after PA compared with those of the control (2.0 μM: 96.6%, 62.1% and 49.1 vs control: 88.3%, 48.8% and 41.4, respectively) and the 10.0 μM groups (87.3%, 41.4% and 40.9, respectively). Oocytes treated with 0.5 μM resveratrol (87.2%, 50.5% and 48.6, respectively) during IVM had significantly higher TCN, but there were no differences in CL and BL formation rates. In experiment 5, a total of 935 oocytes in 3 groups (control, 2.0 and 10.0 μM resveratrol) were conducted in IVF. The BL formation rate and TCN were significantly higher in the group of 2.0 μM resveratrol (20.5% and 54.0, respectively) than the control (11.0% and 43.4, respectively) and 10.0 μM group (11.7% and 45.0, respectively), but there was no significant difference in CL rate. In conclusion, 2.0 μM resveratrol supplementation during IVM improved the developmental potential of PA and IVF in porcine embryos by increasing the intracellular GSH concentration, decreasing the ROS level and decreasing apoptosis-related gene expression during oocyte maturation. This work was supported by a grant from the Next-Generation BioGreen 21 Program (No. PJ008121), Rural Development Administration, Republic of Korea.

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Effects of prematuration culture with a phosphodiesterase-3 inhibitor on oocyte morphology and embryo quality in in vitro maturation

Clinical and Experimental Reproductive Medicine ◽

10.5653/cerm.2021.04413 ◽

2021 ◽

Vol 48 (4) ◽

pp. 352-361

Author(s):

Mohammed Ashraf Cheruveetil ◽

Prasanna Kumar Shetty ◽

Kamini A Rao ◽

Arya Rajendran ◽

Muhammed Asif

Keyword(s):

In Vitro Maturation ◽

Embryo Quality ◽

Germinal Vesicle ◽

Control Group ◽

Developmental Potential ◽

Nuclear Maturation ◽

Phosphodiesterase 3 ◽

The Impact ◽

Experimental Group

Objective: The study assessed the developmental potential of germinal vesicle (GV) oocytes subjected to in vitro maturation (IVM) after prematuration culture with cilostamide (a phosphodiesterase-3 inhibitor) and the impact of cilostamide exposure on the morphology of meiosis II (MII) oocytes and subsequent embryo quality. Methods: In total, 994 oocytes were collected from 63 patients. Among 307 GV oocytes, 140 oocytes were selected for the experimental group and 130 oocytes for the control group. The denuded GV-stage oocytes were cultured for 6 hours with cilostamide in the experimental group and without cilostamide in the control group. After 6 hours, the oocytes in the experimental group were washed and transferred to fresh IVM medium. The maturational status of the oocytes in both groups was examined at 26, 36, and 48 hours. Fertilization was assessed at 18 hours post-intracytoplasmic sperm injection. Embryo quality was assessed on days 3 and 5.Results: In total, 92.1% of the oocytes remained in the GV stage, while 6.4% converted to the MI stage (p<0.01) after cilostamide exposure. In both groups, more MII oocytes were observed at 36 hours (25.8% vs. 21.5%) than at 26 hours (10.8% vs. 14.6%) and 48 hours (13% vs. 7.9%) (p>0.05). With the advenet of cilostamide, blastocyst quality was better in the experimental group than in the control group (p<0.05). Conclusions: Cilostamide effectively blocked nuclear maturation and promoted cytoplasmic growth. Prematuration culture with cilostamide enabled synchronization between cytoplasmic and nuclear maturity, resulting in better blastocyst outcomes.

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Cyclic nucleotide in oocyte In vitro maturation in Assisted Reproductive Technology

Journal of Biomedicine and Translational Research ◽

10.14710/jbtr.v6i3.9691 ◽

2020 ◽

Vol 6 (3) ◽

pp. 110-120

Author(s):

Christie L Sun ◽

Sally L Catt ◽

Kiri Beilby ◽

Mulyoto Pangestu

Keyword(s):

Assisted Reproductive Technology ◽

Natriuretic Peptide ◽

In Vitro Maturation ◽

Reproductive Technology ◽

Developmental Competence ◽

Nuclear Maturation ◽

Oocyte Developmental Competence ◽

Cytoplasmic Maturation ◽

Camp Levels

In vitro maturation (IVM) is a promising assisted reproductive technology (ART) for human infertility treatment. However, when cumulus oocyte complexes (COCs) are removed from their follicular environment when manipulated in vitro, it can lead to a decrease of intra-oocyte cyclic adenosine 3’, 5’-monophosphare (cAMP) causing spontaneous nuclear maturation and an asynchrony with the oocytes’ cytoplasmic maturation, resulting in poor embryo developmental outcomes. Nuclear and cytoplasmic synchrony is important during oocyte maturation within antral follicles.It is maintained partially by the actions of c-type natriuretic peptide (CNP) binding with natriuretic peptide receptor 2 (NPR2), supporting high cAMP levels thus holding the oocyte in meiotic arrest. Addition of CNP to pre-IVM media has the capacity of maintaining cAMP levels and thus improve synchrony. Moreover, in women with advanced maternal age, successful IVM of aging oocytes faces significant challenges due to the morphological and cellular changes. Inhibiting initiation of nuclear maturation by cAMP modulator, CNP during pre-IVM period and thus improve oocyte developmental competence regardless of oocyte age.

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Effects of Vitrification on the Blastocyst Gene Expression Profile in a Porcine Model

International Journal of Molecular Sciences ◽

10.3390/ijms22031222 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1222

Author(s):

Cristina Cuello ◽

Cristina A. Martinez ◽

Josep M. Cambra ◽

Inmaculada Parrilla ◽

Heriberto Rodriguez-Martinez ◽

...

Keyword(s):

Gene Expression ◽

Gene Expression Analysis ◽

Survival Rates ◽

Control Group ◽

P Value ◽

Transcriptome Profile ◽

Embryo Viability ◽

The Impact

This study was designed to investigate the impact of vitrification on the transcriptome profile of blastocysts using a porcine (Sus scrofa) model and a microarray approach. Blastocysts were collected from weaned sows (n = 13). A total of 60 blastocysts were vitrified (treatment group). After warming, vitrified embryos were cultured in vitro for 24 h. Non-vitrified blastocysts (n = 40) were used as controls. After the in vitro culture period, the embryo viability was morphologically assessed. A total of 30 viable embryos per group (three pools of 10 from 4 different donors each) were subjected to gene expression analysis. A fold change cut-off of ±1.5 and a restrictive threshold at p-value < 0.05 were used to distinguish differentially expressed genes (DEGs). The survival rates of vitrified/warmed blastocysts were similar to those of the control (nearly 100%, n.s.). A total of 205 (112 upregulated and 93 downregulated) were identified in the vitrified blastocysts compared to the control group. The vitrification/warming impact was moderate, and it was mainly related to the pathways of cell cycle, cellular senescence, gap junction, and signaling for TFGβ, p53, Fox, and MAPK. In conclusion, vitrification modified the transcriptome of in vivo-derived porcine blastocysts, resulting in minor gene expression changes.

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Oocyte Competence Biomarkers Associated With Oocyte Maturation: A Review

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.710292 ◽

2021 ◽

Vol 9 ◽

Author(s):

Batara Sirait ◽

Budi Wiweko ◽

Ahmad Aulia Jusuf ◽

Dein Iftitah ◽

R. Muharam

Keyword(s):

Oocyte Maturation ◽

Blastocyst Stage ◽

Current Approach ◽

Developmental Competence ◽

Matrix Remodeling ◽

Oocyte Competence ◽

Nuclear Maturation ◽

Oocyte Developmental Competence ◽

Cumulus Oocyte Complex

Oocyte developmental competence is one of the determining factors that influence the outcomes of an IVF cycle regarding the ability of a female gamete to reach maturation, be fertilized, and uphold an embryonic development up until the blastocyst stage. The current approach of assessing the competency of an oocyte is confined to an ambiguous and subjective oocyte morphological evaluation. Over the years, a myriad of biomarkers in the cumulus-oocyte-complex has been identified that could potentially function as molecular predictors for IVF program prognosis. This review aims to describe the predictive significance of several cumulus-oocyte complex (COC) biomarkers in evaluating oocyte developmental competence. A total of eight acclaimed cumulus biomarkers are examined in the study. RT-PCR and microarray analysis were extensively used to assess the significance of these biomarkers in foreseeing oocyte developmental competence. Notably, these biomarkers regulate vital processes associated with oocyte maturation and were found to be differentially expressed in COC encapsulating oocytes of different maturity. The biomarkers were reviewed according to the respective oocyte maturation events namely: nuclear maturation, apoptosis, and extracellular matrix remodeling, and steroid metabolism. Although substantial in vitro evidence was presented to justify the potential use of cumulus biomarkers in predicting oocyte competency and IVF outcomes, the feasibility of assessing these biomarkers as an add-on prognostic procedure in IVF is still restricted due to study challenges.

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Impact of L-carnitine supplementation on the in vitro developmental competence and cryotolerance of buffalo embryos

Veterinary World ◽

10.14202/vetworld.2021.3164-3169 ◽

2021 ◽

pp. 3164-3169

Author(s):

Mohamed M. M. El-Sokary ◽

Al-Shimaa Al-H. H. El-Naby ◽

Amal R. Abd El Hameed ◽

Karima Gh. M. Mahmoud ◽

T. H. Scholkamy

Keyword(s):

Embryo Culture ◽

In Vitro Maturation ◽

Culture Media ◽

Effective Concentration ◽

Developmental Competence ◽

Carnitine Supplementation ◽

Oocyte Developmental Competence ◽

High Lipid ◽

Significant Difference

Background and Aim: Despite many trials, buffalo embryos have poor cryosurvivability because of their high lipid content. L-carnitine was found to be a lipid-reducing agent when added to oocyte and embryo culture media. The study aimed to determine the most effective concentration of L-carnitine to improve the oocyte developmental competence and cryotolerance of buffalo embryos. Materials and Methods: In vitro maturation and embryo culture media were supplemented with four concentrations of L-carnitine: 0 (control), 0.25, 0.5, and 1 mM. Good-quality embryos on 7 days were vitrified using mixtures of dimethyl sulfoxide and ethylene glycol at two concentrations (3.5 and 7 M). Results: The result showed that the cleavage and morula rates were significantly (p<0.05) higher in the 0.5 mM group. Blastocyst rates were significantly (p<0.05) higher at both 0.5 and 1 mM. The rates of viable embryos directly after thawing were significantly (p<0.05) increased in the 0.5 mM group. No significant difference was found in embryos cultured for 24 h after warming among all the groups. Conclusion: The addition of L-carnitine at a concentration of 0.5 mM to the culture media improves the oocyte developmental competence and cryotolerance of buffalo embryos directly after warming but not after 24 h of culture. Nevertheless, further studies must identify how L-carnitine exerts its beneficial micromechanisms.

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