172 Effect of Melatonin on Meiosis Progression and Lipid Content in Bovine Oocytes Matured In Vitro

2018 ◽  
Vol 30 (1) ◽  
pp. 225
Author(s):  
H. Fernandes ◽  
L. Schefer ◽  
F. C. Castro ◽  
D. M. Paschoal ◽  
R. C. Botigelli ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Lipid Content ◽  
Negative Control ◽  
Epifluorescence Microscopy ◽  
Maturation Stage ◽  
Nuclear Maturation ◽  
Positive Effects ◽  
Lipid Contents ◽  
Bovine Oocytes

Melatonin (MLT) may have positive effects on oocyte nuclear maturation and may influence their lipid metabolism. The aim of this study was to assess the effect of MLT on nuclear maturation and lipid content inbovine oocytes during in vitro maturation (IVM). Cumulus-oocyte complexes (30-35/group) were submitted to IVM in TCM-199 supplemented with 3 mg mL−1 BSA (negative control; NC) or with added hormones: 1 µg mL−1 FSH (positive control; PC) or MLT (10−11, 10−9 and 10−7 M), to evaluate the individual action of each treatment on meiosis resumption (metaphase I, MI) at 9 h and progression to metaphase II (MII) at 24 h IVM. Lipid content in oocytes was also assessed. Oocytes were denuded and stained with Hoechst 33342 and Nile Red, and evaluated by epifluorescence microscopy to determine the nuclear maturation stage and lipid content, respectively. The fluorescence intensity (FI) was measured by ImageJ software (National Institutes of Health, Bethesda, MD, USA). Data were analysed by ANOVA followed by Tukey’s test to compare effects of treatments on meiosis resumption and lipid contents at 9 h and on meiosis progression and lipid contents at 24 h; and t-test to compare the same treatment at 9 and 24 h IVM regarding lipid contents (4 replicates/treatment). Significance level was 5% (GraphPrism software; GraphPad Inc., San Diego, CA, USA). At 9 h IVM, meiosis resumption rate (MI) increased (P < 0.05) for MLT 10−9 M (32.6 ± 14.8%, 45/138) and FSH groups (33.9 ± 18.1%, 38/112) compared with NC (4.2 ± 2.7%, 5/120). The other treatments did not differ in relation to NC (20.5 ± 12.5%, 27/132 and 14.9 ± 9.0%, 20/134 to MLT 10−11 and 10−7 M, respectively). Regarding lipid contents at 9 h, MLT 10−11 M showed higher lipid content (8.43 ± 7.61FI; P < 0.0001) compared with other treatments [MLT 10−9 M (5.59 ± 4.13), MLT 10−7 M (4.87 ± 3.21), FSH (5.34 ± 3.66), and NC (4.27 ± 3.28)]. Maturation rate (MII) at 24 h IVM was highest in FSH group (70.1 ± 10.2%, 94/134). No differences were observed (P > 0.05) between groups matured in different concentrations of MLT (65.9 ± 4.2%, 83/126; 62.2 ± 0.6%, 56/90 and 53.5 ± 10.0%, 61/114 for MLT 10−11, 10−9 and 10−7 M, respectively) compared with NC (86.3 ± 1.2%, 88/102; P < 0.05). Similarly, lipid content at 24 h IVM was higher (P < 0.05) in FSH group (10.72 ± 4.71 FI) compared with NC (7.98 ± 3.45 FI) or MLT treatments with 10−11 M (8.90 ± 3.91), 10−9 M (7.85 ± 3.56), and 10−7 M (8.29 ± 3.87). However, MLT 10−7 M, FSH, and NC groups had higher (P < 0.0001) lipid content at 24 than at 9 h. In conclusion, MLT 10−9 M alone was able to stimulate meiosis resumption (9 h) at a rate similar to FSH, but was insufficient to stimulate progression to MII at 24 h, indicating that it may affect nuclear maturation only during the initial steps of meiosis. Lipid contents were increased during IVM but for lower MLT concentrations, this increase was not observed. Whether these observations have any impact on oocyte quality remains to be determined. Further studies are necessary to improve our knowledge of the role of MLT on lipid metabolism and by which mechanism it may affect meiosis resumption in bovine oocytes. This research was funded by FAPESP (HF- 2016/24884-3, scholarship; CLVL, financial support 2015/20379-0).

164 Evaluation of the lipid content of in vitro-matured bovine cumulus - oocyte complexes in the presence of natriuretic peptides A, B, and C types

2019 ◽  
Vol 31 (1) ◽  
pp. 207
Author(s):  
L. Schefer ◽  
K. R. L. Schwarz ◽  
H. Fernandes ◽  
D. M. P. Paschoal ◽  
F. C. C. Castro ◽  
...  
Keyword(s):  
Lipid Content ◽  
Natriuretic Peptides ◽  
Guanosine Monophosphate ◽  
Epifluorescence Microscopy ◽  
Control Group ◽  
In Vitro Production ◽  
Significance Level ◽  
Nuclear Maturation ◽  
Bovine Oocytes

One of the difficulties still observed in in vitro production (IVP) of bovine embryos is the lower cryotolerance of such embryos, which has been related to their increased lipid accumulation during culture in the presence of fetal bovine serum (FBS). Previous studies have indicated that the cyclic guanosine monophosphate (cGMP) pathway may be involved in the lipid metabolism of bovine cumulus-oocyte complexes (COC). Synthesis of cGMP can be caused by activation of membrane guanylate cyclase (mGC), also called natriuretic peptide receptors (NPR1 and NPR2), which are activated by natriuretic peptides (NP) A, B, and C types (NPPA, NPPB, and NPPC). The objective of this study was to investigate the influence of supplementation with NP during in vitro maturation (IVM) on lipid content and nuclear maturation of bovine COC. Pools of 25 COC were submitted to IVM in TCM-199 with 0.2mM sodium pyruvate, 10μg mL−1 gentamicide, 0.5μg mL−1 FSH, 10% FBS, and NPPA (10−5 M), NPPB (10−7 M), or NPPC (10−5 M). The control group was matured without NP. After 24h, cumulus cells (CC) were removed and oocytes (OO) were fixed and permeabilized in 4% paraformaldehyde+0.5% Triton for 20min, stained with 10μg mL−1 Hoechst 33342 for 15min and 1μg mL−1 Nile Red for 30min. Then, the OO were placed in 13μL of ProLong (Thermo Fisher Scientific, Waltham, MA, USA) on glass slides, covered with a coverslip, and submitted to epifluorescence microscopy to evaluate nuclear maturation (emission 445-450nm and excitation 475-490nm) and lipid content (emission 590nm and excitation 516-560nm). Data for 4 replicates/group were tested for normality of results and homogeneity of variance, and then submitted to ANOVA, followed by Tukey test using a GraphPad Prism software (GraphPad Inc., San Diego, CA, USA), with a significance level of 5%. Nuclear maturation was influenced only by one of the NP added to IVM medium, NPPC, which reduced maturation rate (68.3% metaphase II, MII) compared with the control (82.7% MII; P&lt;0.05). Maturation rates of NPPA (79.5% MII) and NPPB (85.1% MII) did not differ from the control (P&gt;0.05). Activation of mGC by NPPB generated oocytes with lower lipid content (34.02±1.2 IF/μm2) compared with control (36.98±0.7 IF/μm2; P&lt;0.05). Neither NPPA (36.5±1.4 IF/μm2) nor NPPC (39.3±1.4 IF/μm2) was able to reduce the lipid content in oocytes matured in vitro relative to control (P&gt;0.05). Different NP may have different effects on maturation and lipid content in in vitro matured bovine oocytes; NPPB may be favourable for reducing the lipid content of matured bovine oocytes in vitro.

277 LIPID ACCUMULATION DURING BOVINE OOCYTES Gyr/HOLSTEIN MATURATION COLLECTED BY OPU IN SPOM SYSTEM

2015 ◽  
Vol 27 (1) ◽  
pp. 227
Author(s):  
G. R. Leal ◽  
C. A. S. Monteiro ◽  
H. F. R. A. Saraiva ◽  
A. J. R. Camargo ◽  
C. O. P. Vasconcelos ◽  
...  
Keyword(s):  
Lipid Content ◽  
Lipid Accumulation ◽  
Lipid Analysis ◽  
Fold Increase ◽  
Control Group ◽  
Sodium Pyruvate ◽  
Nuclear Maturation ◽  
Tropical Conditions ◽  
Bovine Oocytes

In vitro embryo production (IVP) is an important tool for cattle breeding. Brazilian dairy systems are based on Gyr/Holstein crossbreds, which integrates adaptability to tropical conditions and milk production. Oocyte quality is crucial for IVP, and lipid accumulation is a detrimental factor. The aim of this study was to assess the effect of SPOM maturation system (Albuz et al. 2010 Hum. Reprod. 25) on lipid accumulation in bovine oocytes. Oocytes obtained by ovum pick-up (OPU) from heifers without ovarian stimulation were transferred to control media (TCM 199 + sodium pyruvate, ITS, penicillin-streptomycin, BSA, FSH, oestrogen, and hCG) or SPOM (2 h pre-IVM: TCM 199 hepes + sodium pyruvate, ITS, penicillin-streptomycin, BSA, IBMX, and forskolin; followed by 28 h IVM: control media + cilostamide) in 5% CO2 atmosphere at 38°C. Oocytes were collected after 20, 24, and 28 h (groups: C20, C24, C28; S20, S24, S28) and evaluated for nuclear maturation using HOECHST (experiment 1, n = 301, 35–62 per group) and lipid content using Oil Red (experiment 2, n = 163, 14–42 per group). Oocytes from 4 replicates were fixed with PFA and stored at 4°C. For Oil Red, all structures were stained and evaluated at the same day. After being washed in 50% ethanol, oocytes were incubated in 0.2% Oil Red O solution for 10 min. Stained area fraction in each oocyte cytoplasm was measured using ImageJ (NIH). Nuclear maturation analysis was performed by Chi-squared test and Lipid analysis by Kruskal-Wallis and Dunn's post-test (P = 0.05). Distinct superscript letters indicate statistical difference between groups. In experiment 1, we detected a reduction in the percentage of matured (MII) oocytes only in S20 group (C20 = 64.28%a, C24 = 74.28%a, C28 = 60.46%a, S20 = 25.8%b, S24 = 59, 01%a, S28 = 74.13%a). In experiment 2, we detected an increase in lipid content in both control and SPOM groups from 20 to 28 h of IVM (S20 = 5.72a ± 4.41, S24 = 15.95bd ± 7.41, S28 = 37.46c ± 8.68, C20 = 8.65a ± 2.58, C24 = 12.14ad ± 8.08, C28 = 18.50b ± 8.09). For SPOM groups, the lipid content increased 2.78-fold from S20 to S24, and 6.54-fold from S20 to S28. In the control group, only in C28 wasa lipid increase detected, 2.13-fold higher than C20 content. Comparing control and SPOM groups at each time point, S28 displayed a 2.02-fold increase in lipid content compared to C28. We concluded that despite SPOM system being effective in maintaining meiotic arrest until 20 h of IVM and forskolin being present during pre-IVM in SPOM groups, Gyr/Holstein crossbreed oocytes obtained by OPU presented a significant increase in lipid content when matured in SPOM system, even higher than observed for the control group. During the last 8 h of IVM we observed a huge lipid accumulation in both systems, suggesting this might be a crucial period.

scholarly journals Identification of the molecular regulation of differences in lipid deposition in dedifferentiated preadipocytes from different chicken tissues

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zheng Ma ◽  
Na Luo ◽  
Lu Liu ◽  
Huanxian Cui ◽  
Jing Li ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
Lipid Content ◽  
Regulatory Network ◽  
Total Lipid Content ◽  
Fatty Acid Transport ◽  
Lipid Deposition ◽  
Ppar Signaling ◽  
The Difference

Abstract Background A body distribution with high intramuscular fat and low abdominal fat is the ideal goal for broiler breeding. Preadipocytes with different origins have differences in terms of metabolism and gene expression. The transcriptome analysis performed in this study of intramuscular preadipocytes (DIMFPs) and adipose tissue-derived preadipocytes (DAFPs) aimed to explore the characteristics of lipid deposition in different chicken preadipocytes by dedifferentiation in vitro. Results Compared with DAFPs, the total lipid content in DIMFPs was reduced (P < 0.05). Moreover, 72 DEGs related to lipid metabolism were screened, which were involved in adipocyte differentiation, fatty acid transport and fatty acid synthesis, lipid stabilization, and lipolysis. Among the 72 DEGs, 19 DEGs were enriched in the PPAR signaling pathway, indicating its main contribution to the regulation of the difference in lipid deposition between DAFPs and DIMFPs. Among these 19 genes, the representative APOA1, ADIPOQ, FABP3, FABP4, FABP7, HMGCS2, LPL and RXRG genes were downregulated, but the ACSL1, FABP5, PCK2, PDPK1, PPARG, SCD, SCD5, and SLC27A6 genes were upregulated (P < 0.05 or P < 0.01) in the DIMFPs. In addition, the well-known pathways affecting lipid metabolism (MAPK, TGF-beta and calcium) and the pathways related to cell communication were enriched, which may also contribute to the regulation of lipid deposition. Finally, the regulatory network for the difference in lipid deposition between chicken DAFPs and DIMFPs was proposed based on the above information. Conclusions Our data suggested a difference in lipid deposition between DIMFPs and DAFPs of chickens in vitro and proposed a molecular regulatory network for the difference in lipid deposition between chicken DAFPs and DIMFPs. The lipid content was significantly increased in DAFPs by the direct mediation of PPAR signaling pathways. These findings provide new insights into the regulation of tissue-specific fat deposition and the optimization of body fat distribution in broilers.

scholarly journals The presence of acylated ghrelin duringin vitromaturation of bovine oocytes induces cumulus cell DNA damage and apoptosis, and impairs early embryo development

Zygote ◽  
2017 ◽  
Vol 25 (5) ◽  
pp. 601-611 ◽  
Author(s):  
Matias A. Sirini ◽  
Juan Mateo Anchordoquy ◽  
Juan Patricio Anchordoquy ◽  
Ana M. Pascua ◽  
Noelia Nikoloff ◽  
...  
Keyword(s):  
Dna Damage ◽  
Embryo Quality ◽  
Cumulus Cell ◽  
Early Embryo ◽  
Acylated Ghrelin ◽  
Cumulus Expansion ◽  
Nuclear Maturation ◽  
Developmental Capacity ◽  
Bovine Oocytes

SummaryThe aim of this study was to investigate the effects of acylated ghrelin supplementation duringin vitromaturation (IVM) of bovine oocytes. IVM medium was supplemented with 20, 40 or 60 pM acylated ghrelin concentrations. Cumulus expansion area and oocyte nuclear maturation were studied as maturation parameters. Cumulus–oocyte complexes (COC) were assessed with the comet, apoptosis and viability assays. Thein vitroeffects of acylated ghrelin on embryo developmental capacity and embryo quality were also evaluated. Results demonstrated that acylated ghrelin did not affect oocyte nuclear maturation and cumulus expansion area. However, it induced cumulus cell (CC) death, apoptosis and DNA damage. The damage increased as a function of the concentration employed. Additionally, the percentages of blastocyst yield, hatching and embryo quality decreased with all acylated ghrelin concentrations tested. Our study highlights the importance of acylated ghrelin in bovine reproduction, suggesting that this metabolic hormone could function as a signal that prevents the progress to reproductive processes.

Treatment with roscovitine and butyrolactone I prior to in vitro maturation alters blastocyst production

Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 24-31 ◽  
Author(s):  
Rosiara Rosária Dias Maziero ◽  
Carlos Renato de Freitas Guaitolini ◽  
Daniela Martins Paschoal ◽  
André Maciel Crespilho ◽  
Bianca Andriolo Monteiro ◽  
...  
Keyword(s):  
In Vitro Maturation ◽  
Study Groups ◽  
Embryo Cryopreservation ◽  
Control Group ◽  
Bovine Embryos ◽  
Nuclear Maturation ◽  
Oocyte Meiosis ◽  
Maturation Index ◽  
Bovine Oocytes

SummaryThis study evaluated the effects of oocyte meiosis inhibitors roscovitine (ROS) and butyrolactone I (BL-I) on in vitro production of bovine embryos. Bovine oocytes were maintained in pre in vitro maturation (pre-IVM) with 25 µM ROS or 100 µM BL-I for 24 h to delay meiosis and for 24 h in in vitro maturation (IVM). Following this treatment, the nuclear maturation index was evaluated. All embryos degenerated following this procedure. In the second set of experiments, oocytes were maintained for 6 or 12 h in pre-IVM with the following three treatments: ROS (25 µM or 12.5 µM), BL-I (100 µM or 50 µM) or a combination of both drugs (6.25 µM ROS and 12.5 µM BL-I). Oocytes were cultivated for 18 or 12 h in IVM. When a meiosis-inducing agent was used during pre-IVM for 24 h, more degenerated oocytes were observed at the end of the IVM period. This effect decreased when the meiotic blocking period was reduced to 6 or 12 h. No significant differences were observed in the blastocyst production rate of oocytes in pre-IVM for 6 h with ROS, BL-I, or ROS + BL-I compared with that of the control group (P > 0.05). However, inhibition of oocytes for 12 h resulted in decreased embryo production compared with that in the controls (P < 0.05). There was no difference in the post-vitrification embryo re-expansion rate between the study groups, showing that the meiotic inhibition for 6 or 12 h did not alter the embryo cryopreservation process.

scholarly journals Effect of Hyaluronan on Developmental Competence and Quality of Oocytes and Obtained Blastocysts fromIn VitroMaturation of Bovine Oocytes

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Jolanta Opiela ◽  
Joanna Romanek ◽  
Daniel Lipiński ◽  
Zdzisław Smorąg
Keyword(s):  
Dna Fragmentation ◽  
Oocyte Maturation ◽  
Developmental Competence ◽  
Meiotic Maturation ◽  
Nuclear Maturation ◽  
Significant Difference ◽  
The Mean ◽  
Bovine Oocytes

The objective of the present study was to evaluate the effect of hyaluronan (HA) during IVM on meiotic maturation, embryonic development, and the quality of oocytes, granulosa cells (GC), and obtained blastocysts. COCs were maturedin vitroin control medium and medium with additional 0.035% or 0.07% of exogenous HA. The meiotic maturity did not differ between the analysed groups. The best rate and the highest quality of obtained blastocysts were observed when 0.07% HA was used. A highly significant difference (P<0.001) was noted in the mean number of apoptotic nuclei per blastocyst and in the DCI between the 0.07% HA and the control blastocysts (P<0.01). Our results suggest that addition of 0.035% HA and 0.07% HA to oocyte maturation media does not affect oocyte nuclear maturation and DNA fragmentation. However, the addition of 0.07% HA during IVM decreases the level of blastocysts DNA fragmentation. Finally, our results suggest that it may be risky to increase the HA concentration during IVM above 0.07% as we found significantly higherBaxmRNA expression levels in GC cultured with 0.07% HA. The final concentration of HA being supplemented to oocyte maturation media is critical for the success of the IVP procedure.

243 EFFECT OF OOCYTE RECOVERY TECHNIQUES ON IN VITRO MATURATION OF SWINE OOCYTES

2009 ◽  
Vol 21 (1) ◽  
pp. 219
Author(s):  
F. R. O. de Barros ◽  
M. G. Marques ◽  
M. D. Goissis ◽  
M. A. Peres ◽  
M. P. Milazzotto ◽  
...  
Keyword(s):  
Follicular Fluid ◽  
Recovery Rate ◽  
In Vitro Maturation ◽  
Metabolic Stress ◽  
Water Bath ◽  
Epifluorescence Microscopy ◽  
Nuclear Maturation ◽  
Oocyte Recovery ◽  
Centrifuge Tube

The aim of this study was to compare 2 different techniques to obtain swine oocytes from abattoir ovaries. Ovaries were washed in saline at 35°C and submitted to slashing or aspiration, simultaneously. For the slashing group, ovaries were held with a hemostat inside a beaker containing 35 mL of HEPES-buffered Tyrode’s media (HbT) and follicles (2–6 mm) were incised with a scalpel. For every 5 slashed ovaries, HbT-containing follicular fluid was transferred to 50-mL centrifuge tubes. For the aspiration group, follicles (2–6 mm) were aspirated using an 18-gauge needle and a 5-mL syringe. The follicular fluid of each ovary was transferred to a 50-mL centrifuge tube. Tubes from both techniques were placed in a water bath at 35°C for 15 min to allow settling of the cumulus–oocyte complexes (COC). The supernatant was removed and the sediment was resuspended in HbT and placed in water bath at 35°C for an additional 15 min. The sediment was resuspended in 15 mL of HbT and COC were recovered under stereomicroscopy. Oocytes were in vitro matured for 44 h in TCM-199 added with 10% porcine follicular fluid (PFF) and hormones (LH and FSH) at 38.5°C, 5% CO2 and high humidity. The oocyte recovery rate of each technique was determined by the ratio between the number of COC and ovaries used. To verify nuclear maturation by epifluorescence microscopy (Zeiss), oocytes were fixed, permeabilized, and incubated in 10 μg mL–1 of RNAse for 30 min and in 10 μg mL–1 of propidium iodide for 10 min. Heat shock protein 70 (HSP70) content was assessed as described in Kawarsky and King (2001 Zygote 9(3), 39–50) to verify the metabolic stress. Data were analyzed by ANOVA and Tukey’s test using the software Statistica for Windows. A level of 5% was considered significant in all assessments. The oocyte recovery rate (COC/ovary) was higher for the slashing group (2.665 ± 0.38) compared with the aspiration group (1.762 ± 0.15). The percentage of oocytes that reached the germinative vesicle (GV) stage (h 0 of maturation) did not differ between groups (100 ± 0 and 86.66 ± 13.36, slashing and aspiration group, respectively). The same was observed for the percentage of oocytes that reached the metaphase II stage (MII, after 44 of maturation; 79.99 ± 9.74 and 96.00 ± 4.00, slashing and aspiration group, respectively). Moreover, no difference at pixel quantification of HSP70 was observed between groups (256.50 ± 42.42 and 238.61 ± 71.18, slashing and aspiration group, respectively). In conclusion, the slashing procedure provided a better oocyte recovery rate compared with the aspiration of ovaries. This technique does not affect nuclear maturation, because no differences were observed regarding the percentage of oocytes that reached the GV and MII stages. In addition, it does not affect HSP70 content, suggesting that the slashing of ovaries does not increase the basal stress of oocytes in an in vitro-maturation system.

53 EFFECT OF ADDITION OF L-CARNITINE AND CONJUGATED LINOLEIC ACID DURING BOVINE EMBRYO CULTURE ON CRYOSURVIVAL, LIPID CONTENT, AND GENE EXPRESSION

2015 ◽  
Vol 27 (1) ◽  
pp. 119
Author(s):  
A. Ruiz ◽  
P. J. Hansen ◽  
J. Block
Keyword(s):  
Gene Expression ◽  
Lipid Metabolism ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Lipid Content ◽  
Embryo Culture ◽  
Blastocyst Stage ◽  
Hatching Rate ◽  
Bovine Embryo

The objective was to determine the effects of addition of l-carnitine (LC) and trans-10, cis-12 conjugated linoleic acid (CLA) during bovine embryo culture on cryosurvival, lipid content, and gene expression. For all experiments, embryos were produced in vitro using abattoir-derived oocytes. Following insemination, presumptive zygotes were randomly assigned in a 2 × 2 factorial to be cultured in SOF-BE1 supplemented with or without 3.03 mM LC and 100 μM CLA until Day 7. For Exp. 1, blastocyst- and expanded-blastocyst-stage embryos (n = 777) were slow-frozen in 1.5 M ethylene glycol. Embryos were thawed and then cultured for 72 h. Re-expansion and hatching rates were recorded at 24, 48, and 72 h. There was no effect of LC on post-thaw re-expansion rates, but CLA reduced (P < 0.05) and tended (P < 0.08) to reduce re-expansion rate at 24 and 48 h, respectively (76.5 ± 2.5 v. 70.4 ± 2.5 and 79.5 ± 2.2 v. 76.0 ± 2.2, respectively). Whereas hatching rate at 72 h tended (P < 0.08) to be higher for embryos cultured with LC (67.8 ± 2.5 v. 74.4 ± 2.5), treatment with CLA reduced (P < 0.05) hatching rate at 48 h (62.3 ± 2.6 v. 54.9 ± 2.6). In Exp. 2, to determine lipid content, expanded blastocyst-stage embryos (n = 263) were harvested and stained using Nile Red. Embryos were examined for fluorescence using an epifluorescence microscope, and intensity of fluorescence per unit area was quantified using ImageJ software (NIH, Bethesda, MD, USA). There was a significant interaction (P < 0.01) between LC and CLA affecting embryo lipid content. Whereas addition of CLA during culture increased lipid, treatment with LC and the combination of LC and CLA reduced lipid (22.8 ± 1.1 v. 19.1 ± 1.1 v. 28.4 ± 1.1 v. 19.2 ± 1.2 for no additive, +LC, +CLA, and +LC and CLA, respectively). For Exp. 3, the effect of LC and CLA on the relative abundance of genes involved in lipid metabolism (ELOVL6, SCD1, SQLE, HMGCS1, CYP51A1, FDPS, FDFT1, LDLR, and SC4MOL) was determined. Pools of 5 expanded blastocyst-stage embryos from each treatment were collected across 5 replicates. The RNA was purified and synthesised into cDNA for RT-qPCR analysis. The SDHA, GAPDH, and YWAZ were used as housekeeping genes. Addition of LC during culture reduced (P < 0.05) the abundance of 4 of the 9 genes analysed (SQLE, HMGCS1, CYP51A1, and FDPS) and tended (P < 0.08) to reduce a fifth (FDFT1). In addition, there was a tendency (P < 0.08) for LC to increase the abundance of SCD1. Addition of CLA during culture had minimal effects on transcript abundance. In particular, CLA treatment reduced (P < 0.01) ELOVL6 and tended (P < 0.08) to increase SCD1. In contrast to previous studies, post-thaw cryosurvival was not significantly improved by treatment with LC or CLA. Results indicate that reduced embryo lipid content caused by LC treatment is due, in part, to an alteration in the abundance of genes involved in lipid metabolism. Further research is still necessary to determine whether in vivo survival following transfer of cryopreserved embryos can be enhanced by treatment with LC or CLA.Support was provided by USDA AFRI Grant 2010–85122–20623.

165 FETAL CALF SERUM INFLUENCES CYCLIC GMP PATHWAY, WHICH IN TURN AFFECTS THE LIPID CONTENT IN IN VITRO-MATURED BOVINE OOCYTES

2014 ◽  
Vol 26 (1) ◽  
pp. 196
Author(s):  
K. R. L. Schwarz ◽  
R. C. Botigelli ◽  
F. C. Castro ◽  
M. R. Chiaratti ◽  
C. L. V. Leal
Keyword(s):  
Lipid Content ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Cumulus Cells ◽  
Control Group ◽  
Maturation Medium ◽  
Cgmp Pathway ◽  
Bovine Oocytes ◽  
Synthesis And Degradation

The sensitivity of IVP embryos to cryopreservation is often associated with lipid accumulation in the cytoplasm induced by the presence of fetal calf serum (FCS) during culture. Intracellular levels of cyclic (c)AMP and cGMP are involved in the regulation of lipolysis in adipocytes; high levels stimulate lipolysis whereas low levels lead to lipogenesis. Both nucleotides are present in bovine oocytes, together with the enzymes for their synthesis and degradation. The aim of this study was to analysis the effect of FCS on the cGMP pathway and the influence of cGMP on cytoplasmic lipids in bovine oocytes. In experiments 1 and 2, cumulus–oocyte complexes (COC) were cultured for 24 h in maturation medium with different proportions of FCS (2 and 10%) and a control group was matured with 0.4% BSA. After this period, transcripts for cGMP pathway were assessed by real-time PCR (GUCY1B3 and PDE5, cGMP synthesis and degradation enzymes, respectively; experiment 1) in oocytes and cumulus cells, and cGMP levels were measured in COC using commercial enzyme immunoassay kits (EIA; experiment 2). In experiments 3 and 4, COC were matured for 24 h with 0.4% BSA and different concentrations of the phosphodiesterase (PDE)5 inhibitor (0, 10–7, and 10–5 M sildenafil) to inhibit cGMP degradation and a control group was matured with 0.4% BSA. The nucleotide levels were measured in COC (experiment 3) and the oocytes were stained with Nile Red (1 μg mL–1) for evaluation of lipid content (experiment 4). Statistical analyses were performed by ANOVA followed by Tukey post hoc test using SAS software (SAS Institute Inc., Cary, NC, USA). Data for gene expression from 5 replicates and for cGMP measurements and lipid content from 3 replicates were log10-transformed into before analyses. The level of significance was 5%. The presence of FCS reduced GUCY1B3 expression in both cells and increased PDE5A in cumulus cells (P < 0.05). In experiment 2, the groups treated with 2 (0.64 fmol/COC) and 10% FCS (1.04 fmol/COC) showed decreased cGMP levels compared with control (9.46 fmol/COC; P < 0.05). In experiment 3, inhibition of PDE5A increased cGMP levels in the treated groups (36 and 56 fmol/COC for 10–7 and 10–5 M sildenafil, respectively) compared with control (9.5 fmol/COC; P < 0.05). Therefore, sildenafil showed inverse effects compared with FCS (experiment 2). In experiment 4, oocytes treated with 10–7 and 10–5 M sildenafil showed a reduced lipid content compared with controls (11.6 ± 9.4 v. 13.9 μm2 fluorescence intensity, respectively; P < 0.05). The results suggest that FCS in maturation medium affects the cGMP pathway, interfering with the transcription of genes that control its levels, which in turn results in nucleotide reduction. Inhibition of PDE5 increases cGMP levels and reduces the lipid content of oocytes, indicating that changes in this pathway caused by FCS may affect lipid metabolism of oocytes. More studies are underway to better understand this mechanism. The authors acknowledge FAPESP 2012/00170-0 for financial support.

174 Effects of Melatonin on In Vitro Maturation of Bovine Oocytes and Gene Expression in Cumulus Cells: Preliminary Results

2018 ◽  
Vol 30 (1) ◽  
pp. 226
Author(s):  
F. C. Castro ◽  
L. Schefer ◽  
K. L. Schwarz ◽  
H. Fernandes ◽  
R. C. Botigelli ◽  
...  
Keyword(s):  
Gene Expression ◽  
In Vitro Culture ◽  
Reverse Transcription ◽  
In Vitro Maturation ◽  
Cumulus Cells ◽  
Culture Conditions ◽  
Nuclear Maturation ◽  
Maturation Rate ◽  
Bovine Oocytes

Melatonin mediates several processes in animal reproduction and has drawn attention for its potent antioxidant, anti-apoptotic, anti-inflammatory action and, more recently, for its benefits on oocyte maturation and embryo development in vitro. The aim of this study was to assess the effect of melatonin during the in vitro maturation (IVM) on nuclear maturation of bovine oocytes and gene expression in their corresponding cumulus cells (CC). Bovine cumulus–oocyte complexes (COC) were obtained by aspiration of follicles (2-6 mm) from slaughterhouse ovaries, selected (grades I and II) and transferred to 4 well plates (25-30 COC/well) containing IVM medium [TCM-199 supplemented with sodium bicarbonate (26 mM), sodium pyruvate (0.25 mM), FSH (0.5 µg mL−1), LH (5.0 µg mL−1), 0.3% BSA, and gentamicin (50 µg mL−1)] with 0, 10−5, 10−7, 10−9 or 10−11 M melatonin and cultured for 24 h at 38.5°C and 5% CO2. At the end of IVM, oocytes were stained with Hoechst 33342 (10 μg mL−1) and evaluated for nuclear maturation rate. The CC were evaluated for the expression of antioxidant (SOD1, SOD2, GPX4), pro-apoptotic (P53, BAX) and expansion-related genes (PTX3, HAS1, HAS2). For transcript detection in CC, RNA isolation was performed with TRIzol®Reagent (Invitrogen, Carlsbad, CA, USA) and reverse transcription with High Capacity cDNA Reverse Transcription kit (Applied Biosystems, Foster City, CA, USA). Relative quantification of transcripts was performed by RT-qPCR using 3 endogenous controls (β-actin, GAPDH, PPIA). Nuclear maturation rate and gene expression were tested by ANOVA and means were compared by Tukey’s test (6 replicates). In CC, the different concentrations of melatonin did not significantly alter expression of the investigated genes (P > 0.05), although all concentrations provided a numerical increase in the expression of the antioxidant SOD1 and of the expansion-related genes PTX3 and HAS2. Regarding the pro-apoptotic genes, concentrations of 10−11 and 10−9 M were able to reduce only numerically the expression of BAX and P53, respectively. In oocytes, the rate of nuclear maturation was not different among the tested treatments (P > 0.05), but it was numerically higher in the 10−7 M melatonin treated group compared with the control (69.71 ± 13.76% v. 88.1 ± 12.54%). In conclusion, under the studied conditions, melatonin was unable to improve maturation rate or to affect the expression of antioxidant, pro-apoptotic, and expansion-related genes in CC. Melatonin during IVM has shown variable results in different studies and appears to show different effects depending on culture conditions and parameters studied. In order to take advantage of the possible positive antioxidant effects of melatonin, other culture conditions and parameters should be investigated. In a next step, melatonin will be included during in vitro culture of embryos to evaluate its possible cytoprotective role, because such embryos are more exposed to oxidative stress during in vitro culture, and to investigate its benefits on developmental competence in vitro. This reaesrch was funded by FAPESP (2015/20379-0; 2014/17181-0).

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