55 Donor age has the least influence on recovery, quality, and in vitro developmental competence of ovum pickup–based Holstein Friesian oocytes under subtropical conditions

2021 ◽  
Vol 33 (2) ◽  
pp. 134
Author(s):  
M. Yaseen ◽  
M. Saleem ◽  
M. Nawaz ◽  
N. Ahmad ◽  
A. Riaz

The use of oocytes obtained from younger donors for invitro fertilization followed by embryo transfer represents an opportunity to accelerate genetic gain by reducing generation interval. The present study was designed to evaluate the effect of age of donor on the follicular population, recovery, quality and invitro developmental competence of ovum pickup based Holstein Friesian oocytes under subtropical conditions. A total of eight (n=8) Holstein Friesian (with proper oestrus cyclicity) were selected for the study and divided into 2 groups based on animal age: (1) heifers (n=4), 1.5 to 2 years of age, and (2) adults (n=4), 5 to 6 years of age. The study was conducted near Lahore (31°33′ N, 74°19′ E), Punjab, Pakistan, from November 2019 to February 2020. The animals were wave synchronized using the physiological method of wave synchronization. After 4 days of second dominant follicle puncture, the first ovum pickup was carried out and a total of nine (n=9) OPU sessions were held for each group. The COCs from the follicles were aspirated using a transvaginal ultrasound–guided needle. Following searching and grading, COCs of grade A, B and C were processed for IVM in 100-µL droplets of BO-IVM under mineral oil at 37°C, 5% CO2, and 95% humidity for 24h. The frozen semen of a high-pedigree bull was thawed at 37°C and observed for post-thaw sperm motility. The semen samples of the same bull having motility >50% were processed using the sperm swim-up method throughout the study. The IVF was carried out by placing the COCs and required amount of sperm in 100-µL droplets of BO-IVF at similar conditions for a maximum of 18h. The presumptive zygotes were denuded by gentle pipetting and cultured for a period of 7 days after placing in 100-µL drops of BO-IVC at 37°C, 5% CO2, 5% O2, and maximum humidity. The presumptive zygotes were observed for cleavage rate and blastocyst rate on Days 2 and 7 following COCs-sperm co-incubation. Data on the follicular population, oocytes recovered, and viable oocytes were analysed by the PROC GLIMMIX of SAS (SAS Institute Inc.), and proportional data were analysed by the Chi-squared method using SAS 9.1. COCs of grade AB (35.2 vs. 25.4%) were higher (P>0.05) in the adult group than in the heifer group, respectively. Similarly, COCs with grade CD (57.5 vs. 71.9%) were lower (P<0.05) in the adult group compared with the heifer group, respectively. However, the total follicles (6.55±0.42 vs. 6.39±0.39), number of COCs recovered (3.33±0.32 vs. 3.17±0.41), viable oocytes (3.08±0.29 vs. 3.08±0.39), cleavage rate (60.3 vs. 68.7%), and blastocyst rate (38.7 vs. 48.8%) did not differ (P>0.05) between the groups. To conclude, donor age up to third lactation, under subtropical conditions, does not affect invitro embryo production in Holstein Friesian undergoing repeated OPU.

2014 ◽  
Vol 26 (1) ◽  
pp. 123
Author(s):  
Y. Liu ◽  
A. Lucas-Hahn ◽  
B. Petersen ◽  
R. Li ◽  
P. Hassel ◽  
...  

Two nuclear transfer (NT) techniques are routinely used to produce cloned animals, traditional cloning (TC) and handmade cloning (HMC). The TC embryos keep their zona and can be transferred at early stages, whereas HMC embryos are zona-free and must be cultured to the morula/blastocyst stage before transfer. Some studies have shown that in vitro culture reduces embryo development and quality, but it is not known whether embryos produced by TC or HMC differ because of the NT method or the in vitro culture. Therefore, we investigated the developmental competence and histone acetylation (H3K18ac) of porcine NT embryos produced by TC and HMC with (Day 5 and 6) or without (Day 0) in vitro culture. Nuclear transfer experiments were performed on same day (Day 0), using same batch of porcine oocytes and donor cells and same in vitro culture conditions. Cloning procedures were previously described (TC : Cloning Stem Cells 10 : 355; HMC : Zygote 20 : 61). Parthenogenetically activated embryos (PA) were used as control of activation and culture conditions. Embryos from all groups were collected for immunostaining of H3K18ac on Days 0, 5, and 6. The normalized H3K18ac level was calculated as previously described (Epigenetics 6 : 177). Cell numbers per blastocyst in each group were counted on Days 5 and 6. The cleavage rate (Day 2) and blastocyst rates (Days 5 and 6) between groups were analysed by Chi-squared test, whereas cell number per blastocysts and H3K18ac level between groups and days were analysed by ANOVA (SAS version 9.2; SAS Institute Inc., Cary, NC, USA). Cleavage rate of HMC embryos was lower than that of TC embryos, but blastocyst rate and cell number per blastocyst were higher in the HMC group compared with TC (Table 1). Differences of H3K18ac level between HMC, TC, and PA groups were only observed on Day 6 but not on Day 0 or Day 5. Within HMC and TC groups, there was no difference in H3K18ac level between Day 0 and Day 5, but the level was lower on Day 6 compared with Day 5 in the HMC group, whereas the TC group displayed the opposite pattern. In conclusion, NT embryos produced by HMC show higher blastocyst rate and cell number per blastocyst compared with TC embryos. Both in vitro culture and the NT method result in differences of the normalized H3K18ac levels. Further study is needed to investigate putative differences between NT embryos produced by HMC and TC compared to in vivo embryos also after transfer to recipients. Table 1.Cleavage and blastocyst rate, cell numbers, and normalized H3K18ac level for handmade cloning (HMC), traditional cloning (TC), and parthenogenetically activated (PA) embryos1


2010 ◽  
Vol 22 (1) ◽  
pp. 287 ◽  
Author(s):  
M. C. Abraham ◽  
A. Ruete ◽  
Y. C. B. Brandt

Fertility among cattle breeds can vary. The Swedish Red and White dairy breed (SRB) has been systematically bred for good reproductive traits since 1970 and might therefore have retained a better oocyte quality than other dairy breeds. The aim of this study was to determine if the breed of oocyte donor affects the development of embryos using IVM, IVF, and IVC. Oocyte developmental competence in vitro was compared between the SRB (n = 77 animals), the Swedish Holstein breed (SLB, n = 49), and beef breeds (mixed breeds, n = 97). The oocytes (n = 1380, 18 batches) were aspirated from abattoir-derived ovaries from healthy animals with known identity. Statistical analyses were performed using Student’s t-tests and generalized linear mixed models with random effects. The time of collection in relation to slaughter and time of day, as well as aspiration and the following in vitro procedures, were consistent throughout the experiment. The oocytes were matured, fertilized (frozen semen), and cultured according to conventional protocols without serum. Data are presented as mean ± SEM. The SRB and SLB groups were comparable in age [SRB: 66% cows (over 3 years of age), 27% young cows (calved at least once but not over 3 years of age), and 7% heifers; SLB: 63% cows, 20% young cows, and 17% heifers], carcass classification (scale 1-15, where 15 = highest amount of muscle; SRB: 3.8 ± 0.2, SLB 3.5 ± 0.3), body fat (scale 1-15, where 15 =highest amount of fat; SRB: 8.4 ± 0.4, SLB 8.8 ± 0.5) and kilograms of carcass weight (SRB: 297.3±7.4, SLB: 311.6 ± 9.0). The beef group had a significantly higher mean carcass classification (6.2 ± 0.2) and a different age distribution with a higher proportion of heifers (38% cows, 12% young cows, and 50% heifers), but was comparable in body fat content (8.5 ± 0.4) and kilograms of carcass weight (310.9 ± 7.9). Cleavage rate, number of embryos developed beyond the 2-cell stage by 44 h post-fertilization, and the number of blastocysts developed by Days 7 and 8 were noted. All blastocysts were graded and stained with Hoechst 33 342 and the number of nuclei was determined. Cleavage rate was not different among the breeds (SRB: 71.9 ± 0.03%, SLB: 72.5 ± 0.02%, beef: 73.9 ± 0.03%). The percentage of embryos developed beyond 2-cells (from cleaved) did not differ between the beef and SRB (beef: 65.1 ± 6.1%; SRB: 70.4 ± 4.9%) but SLB was significantly greater than than the other breeds (75.4 ± 4.5%). The percentage of blastocysts developed by Day 8 was significantly higher in the beef (21.1 ± 2.7%) and SRB (23.3 ± 3.5%) breeds compared with the SLB (12.5 ± 2.4%). There was no significant difference in blastocyst grades among breeds (scale 1-4, where 1 = highest grade; SRB: 2.4 ± 0.1, SLB: 2.4 ± 0.2, beef: 2.1 ± 0.2), but the number of nuclei in Day 8 blastocysts was significantly lower in the SLB (SRB: 98.9 ± 7.7, SLB: 79.2 ± 8.7, beef: 101.4 ± 6.9). In conclusion, the breed of origin of the oocytes is an important factors affecting the development during in vitro embryo production in cattle. Funded by Formas.


2011 ◽  
Vol 23 (1) ◽  
pp. 135
Author(s):  
S. K. Panda ◽  
A. George ◽  
A. P. Saha ◽  
R. Sharma ◽  
N. M. Kamble ◽  
...  

Despite recent successes in the birth of buffalo calves cloned through SCNT or hand-guided cloning (HGC), the cloning efficiency is very low in this species because of lack of information on factors that influence it. The goal of this study was to examine the effects of cytoplasmic volume on the developmental competence of cloned buffalo embryos produced by HGC. In vitro matured oocytes were stripped of their cumulus investment and zona pellucida using hyaluronidase and pronase, respectively. Protrusion cone-guided bisection of zona-free oocytes was performed to remove the nucleus. For reconstructing control HGC embryos, 2 enucleated oocytes (demi-cytoplasts) were fused with a single somatic cell. For reconstruction of embryos with lower or higher cytoplasmic volume, 1 or 3 demi-cytoplasts were fused, respectively, with the donor somatic cell. 2 different cell types, i.e. buffalo fetal fibroblasts (BFF) between passage 10 and 15 and buffalo embryonic stem cell (ESC)-like cells between passage 22 and 25 were used as nuclear donors in 2 different experiments. Data were analysed by 1-way ANOVA after arcsine transformation of percentage values. For BFF, the blastocyst rate for doublet and triplet embryos were significantly higher (P ≤ 0.01) than that for singlet embryos despite the cleavage rate for the 3 groups being similar. For the ESC-like cells, the cleavage and the blastocyst rate were significantly lower (P ≤ 0.01) for the singlet than that for the doublet embryos. The pregnancies were established only in doublet and triplet embryo groups using BFF cells and in the doublet embryo group using ESC-like cells. These results indicate that increasing the cytoplasmic volume could be helpful in improving cloning efficiency in terms of blastocyst production rate in buffaloes. Table 1.Effect of cytoplasmic volume on the developmental competence of cloned buffalo embryos This work was funded by NAIP grant C 2-1-(5)/2007 to SKS.


2015 ◽  
Vol 27 (1) ◽  
pp. 243
Author(s):  
M. E. Dell'Aquila ◽  
F. Ariu ◽  
N. A. Martino ◽  
F. Minervini ◽  
A. Cardinali ◽  
...  

Verbascoside (VB), a bioactive polyphenol from olive mill wastewater with known antioxidant activity, was shown to act as a pro-oxidant molecule, by impairing energy/redox status and embryo developmental competence of prepubertal ovine oocytes when added at micromolar concentrations in a continuative 24-h in vitro maturation (IVM) exposure protocol (1). The aim of the present study was to determine whether a lower (nanomolar) VB concentration and a shorter exposure time (2 v. 24 h) during IVM may improve the maturation rates of prepubertal ovine oocytes and their subsequent embryonic development in vitro. Cumulus-oocyte complexes derived from the ovaries of slaughtered 1-mo-old prepubertal sheep oocytes underwent IVM in TCM 199 with 10% oestrus sheep serum, 0.1 IU mL–1 of FSH/LH, and 100 µM cysteamine, in 5% CO2 in air at 38.5°C for 24 h. Based on our previous results (Dell'Aquila et al. 2014 Biomed. Res. Int. 2014, 878062), VB was added in the IVM medium at 1.03 nM, and 2 incubation times (24 and 2 h) were tested. In the 2-h exposure group, after 2 h of exposure to VB, oocytes were washed and cultured up to 24 h without VB. A group of oocytes were cultured in absence of VB, as controls. Matured oocytes were fertilized with frozen-thawed ram semen in SOF medium for 22 h and zygotes were cultured in vitro for 8 days. Metaphase II (MII) cleavage and blastocyst rates were analysed by Chi-squared test. Embryo quality was evaluated by staining and total cell count of the blastocyst and analysis of variance (ANOVA) was applied. Differences were considered to be significant when P < 0.05. Compared to controls, VB treatment at the concentration of 1.03 nM and 24 h of exposure had no effect on MII rates (196/268, 73% v. 226/323, 70% MII/cultured oocytes; P > 0.05). However, this treatment allowed to obtain significantly higher rates of cleaved embryos/MII oocytes (156/196, 80% v. 165/226, 73%; respectively; P < 0.05), blastocyst yield/cleaved embryos (59/156, 38% v. 45/165, 27%, respectively; P < 0.05), and total blastocyst cell numbers (108.62 ± 19.87 v. 89.61 ± 26.32, respectively; P < 0.05) compared to control oocytes. The VB treatment at the same concentration but for 2 h induced only significantly higher cleavage rate (196/210, 93% v. 165/226, 73%; P < 0.05). In conclusion, our results showed that VB treatment at 1.03 nM during 24 h of IVM exerted a positive effect on in vitro embryo development of prepubertal ovine oocytes by increasing the blastocyst yield and their quality. The hypothesis that VB at nanomolar concentrations may improve cumulus-oocyte energy/redox status is under investigation.The authors acknowledge support by the Regione Autonoma della Sardegna (LR 7, Agosto 2007, no. 7, CRP-17602). The authors thank Dr D. Bebbere and L. Falchi, Dept. Veterinary Medicine, Sassari, for statistical analysis.


Zygote ◽  
2014 ◽  
Vol 23 (4) ◽  
pp. 563-572 ◽  
Author(s):  
Gustavo Bruno Mota ◽  
Ingrid Oliveira e Silva ◽  
Danielle Kaiser de Souza ◽  
Flavia Tuany ◽  
Michele Munk Pereira ◽  
...  

SummaryThe aim of this study was to evaluate the dose–response effect of insulin, plus follicle-simulating hormone (FSH) at a fixed concentration, in a serum-free defined culture medium (DCM) on the in vitro maturation of bovine cumulus–oocyte complexes (COCs). For oocyte nuclear maturation, the expression levels of GDF9, GLUT1, PRDX1 and HSP70.1 transcripts related to oocyte and embryo developmental competence were analysed. For in vitro maturation (IVM), cumulus–oocyte complexes from slaughterhouse ovaries were distributed into four groups based on insulin concentration added to serum-free DCM, which was composed of alpha minimum essential medium (α-MEM), as basal medium: (1) DCM control: 0 ng/ml; (2) DCM1: 1 ng/ml; (3) DCM10: 10 ng/ml; and (4) DCM100: 100 ng/ml. After IVM, the nuclear status of a sample of oocytes was analysed and the other oocytes were submitted for in vitro fertilization (IVF) and in vitro culture (IVC). Different concentrations of insulin did not affect significantly the nuclear maturation and cleavage rate (72 h post-insemination) across all groups. Blastocyst rate (192 h post-insemination) did not differ in DCM control (24.3%), DCM1 (27.0%) and DCM10 (26.3%) groups, but the DCM100 (36.1%) group showed a greater blastocyst rate (P < 0.05) than the DCM control. Insulin concentrations of 1, 10, or 100 ng/ml decreased the relative levels of GDF9 and HSP70-1 transcripts in oocytes at the end of IVM (P < 0.05). The transcripts levels of PRDX1 decreased (P < 0.05) only when 10 or 100 ng/ml insulin was added to the DCM medium. No difference in levels of GLUT1 transcripts (P > 0.05) was observed at the different insulin concentrations. The results indicated that insulin added to DCM influenced levels of transcripts related to cellular stress (HSP70-1 and PRDX1) and oocyte competence (GDF9) in bovine oocytes and at higher concentrations enhanced blastocyst production.


2010 ◽  
Vol 22 (1) ◽  
pp. 332 ◽  
Author(s):  
I. Molina ◽  
M. Muñoz ◽  
C. Díez ◽  
E. Gómez ◽  
E. A. Martínez ◽  
...  

The meiotic spindle in the oocyte is composed of microtubules and plays an important role during chromosome alignment and separation at meiosis. Polarized light microscopy (PLM) is used as a tool in human and, recently, in farm animals assisted reproductive technologies. PLM could be useful for a non-invasive evaluation of the meiotic spindle. The objectives of the present study were to assess the efficiency of PLM to detect microtubule-polymerized protein within in vitro-matured porcine oocytes and to examine the effects of PLM on the oocyte developmental competence. Cumulus-oocyte complexes from slaughterhouse ovaries were matured in vitro for 42 h as described by Gil et al. (2004 Theriogenology 62, 544-552). In the first experiment, a total of 97 oocytes from 6 replicates were placed individually in 10-μL drops of TCM-199-Hepes-FCS in a glass Petri dish. PLM was used to detect the presence of polymerized protein which could be forming a meiotic spindle. The presence of polymerized protein and a meiotic spindle was confirmed in individual oocytes by inmunostaining and chromatin detection as described by Morató et al. (2008 Mol. Reprod. Dev. 75, 191-201). In the second experiment, a total of 160 oocytes from 4 replicates were exposed or not (controls) to PLM for 10 minutes. Thereafter, the oocytes were parthenogenetically activated and cultured in vitro. Cleavage rate, total blastocyst rate, expanded blastocyst rate on Day 7 and total cell numbers in expanded blastocysts were assessed. Data were analyzed by GLM procedure of SAS. There was a positive correlation (r = 1; P < 0.0001) between the signal obtained by PLM and the presence of microtubule-polymerized protein as confirmed by inmunostaining. A positive PLM signal was detected in 98.9% of the oocytes. A barrel-shape spindle was observed in 94.8% of the individual samples by inmunostaining and all of these oocytes were positive to PLM. Moreover, oocytes exposed to PLM did not differ significantly from controls on cleavage rate (83.7 ± 1.5 v. 84.4 ± 1.5), total blastocyst rate (36.9 ± 3.6 v. 41.2 ± 3.6) and expanded blastocyst rate on Day 7 (21.9 ± 1.7 v. 26.2 ± 1.7), respectively. There were also no differences in total cell numbers counted in expanded blastocysts (32.8 ± 2.6 v. 35.6 ± 2.5). These results indicate that polarized light microscopy did not exert detrimental effects on porcine oocyte developmental competence and it seems an efficient system to detect polymerized protein in in vitro-matured porcine oocytes. Grant support: INIA: RZ2007-00013-00-00. I. Molina, M. Muñoz, B. Trigal and D. Martín are sponsored by INIA, RYC08-03454, Cajastur and PTA2007-0268-I, respectively.


2011 ◽  
Vol 23 (1) ◽  
pp. 130
Author(s):  
J. Li ◽  
J. Adamsen ◽  
R. Li ◽  
H. Pedersen ◽  
Y. Liu ◽  
...  

One of the primary factors influencing the developmental ability of cloned embryos is the oocyte′s diameter (Hirao et al. 1994 J. Reprod. Fertil. 100, 333–339). However, the oocyte donor's age (i.e. its sexual maturity) is also important to consider, because a high proportion of immature oocytes can be expected (Ikeda and Takahashi 2003 Reprod. Fertil. Dev. 15, 215–221). The present study was to investigate the effect of diameter of oocytes collected from prepubertal gilts weighing 100 to 120 kg on the developmental ability of cloned and parthenogenetically activated (PA) embryos. Cumulus–oocyte complexes collected from ovaries of prepubertal gilts were in vitro matured for 42 to 44 h as described for sow oocytes (Li et al. 2008 Theriog 70, 800–808). After removal of the cumulus cells, the matured oocytes were sorted into 2 groups based on visual inspection: large (L) and small (S) oocytes, whereas non-sorted oocytes were used as control (C). In addition, 1 batch from each of the 3 groups of oocytes had their mean size measured. Subsequently, all 3 groups were used for handmade cloning (HMC; Li et al. 2009 Reprod. Domest. Anim. 44, 122–127) or parthenogenetic activation (PA; Kragh et al. 2005 Theriogenology 64, 1536–1545). Then a chemical activation with 5 μg mL–1 cytochalasin B and 10 μg mL–1 cycloheximide in PZM-3 medium was applied for 4 h on both HMC and PA embryos. Finally, the activated embryos were washed and cultured in PZM-3 medium using the WOW system. The embryo development was evaluated by cleavage rate (Day 2), blastocyst rate (Day 6), and total cell number in blastocysts. Data were analysed by ANOVA with single factor in Excel (Microsoft Excel 2007, Redmond, WA, USA). The results showed (Table 1) that by simple visual observation, oocytes could be easily sorted into the following groups: L group (mean diameter 110 μm, from 105 to 116 μm), S group (mean diameter 101 μm, from 93 to 106 μm) and C group (mean diameter 107 μm, from 93 to 116 μm). Cleavage rates and total cell number were similar in the 3 groups. However, the blastocyst rate in L group either for HMC or PA was higher than S group. The data confirm that prepubertal gilt oocytes are useful for cloning and PA, but developmental rates can be increased by selection of large oocytes by simple visual observation. Table 1.Data analysis results


2009 ◽  
Vol 21 (1) ◽  
pp. 224
Author(s):  
M. M. Pereira ◽  
F. Q. Costa ◽  
P. H. A. Campos ◽  
R. V. Serapiao ◽  
J. Polisseni ◽  
...  

In vitro maturation (IVM) is a critical step in in vitro bovine embryo production. A number of factors can influence the IVM environment, such as media composition and protein supplementation. Serum and higher O2 tension have been shown to reduce embryo quality; however, little is known about the effects of serum and O2 tension during IVM on embryo quality and development. This study aimed to evaluate the effect of serum and O2 tension on IVM of bovine oocytes. Immature oocytes obtained from slaughterhouse ovaries were randomly distributed in 4 groups of IVM: G1 (n = 253), 0.1% polyvinyl alcohol (PVA) in air; G2 (n = 248), 10% inactivated estrous cow serum (ECS) in air; G3 (n = 270), 0.1% PVA under 5% O2; and G4 (n = 236), 10% ECS under 5% O2. In vitro maturation was performed with TCM-199 culture medium supplemented with 20 μg mL–1 FSH, under 5% CO2 at 38.5°C for 24 h. After maturation, oocytes were in vitro fertilized with 2.0 × 106 sperm mL–1 in Fert TALP medium, supplemented with heparin, for 20 h. Presumptive zygotes were denuded by vortexing and cultured in CR2aa medium with 2.5% fetal calf serum under 5% CO2 and 5% O2 at 38.5°C. Cleavage rate was evaluated 72 h postfertilization, and blastocyst rate and total cell number were evaluated 8 days postfertilization. Morphological classification of embryos was performed at Day 8 according to the International Embryo Transfer Society manual (1998). Cleavage, blastocyst, and grade 1 embryo rates were analyzed by chi-square, and total cell number was analyzed by ANOVA, with means compared by LSD. Results are presented as mean ± SEM. There was no difference (P > 0.05) in cleavage rates among G1, G2, and G4 (61.6, 65.3, and 57.6%, respectively), but cleavage rate was lower (P < 0.05) in G3 (52.5%). Blastocyst rates among G1, G3, and G4 (15.8, 17.7, and 20.3%, respectively) were similar (P > 0.05). However, blastocyst rate in G2 (25.0%) was higher (P < 0.05) than in G1 and G3, but was similar to G4 (P > 0.05). Total cell number was similar (P > 0.05) among G2 (194.1 ± 13.1), G3 (173.3 ± 9.0), and G4 (163.8 ± 8.7), but was lower (P < 0.05) in G1 (124.5 ± 11.4). The grade 1 embryo rate was lower (P < 0.05) in G1 (70.3%) than in G2 (89.5%), but was similar (P > 0.05) to G3 (77.0%) and G4 (83.9%). The results suggest that IVM with PVA in TCM-199 medium under 5% O2 can be performed without reducing embryo development and quality, when compared with ECS. On the other hand, oocyte developmental competence seems to be affected when IVM is performed with PVA under air conditions. Financial support: CNPq, FAPEMIG.


2021 ◽  
Vol 33 (2) ◽  
pp. 178
Author(s):  
P. R. Cruzans ◽  
M. S. Lorenzo ◽  
G. M. Teplitz ◽  
C. G. Luchetti ◽  
D. M. Lombardo

l-Carnitine (LC) plays an important role in the catabolism of lipids and protects cells from the damage caused by reactive oxygen species due to its antioxidant activity. The aim of this study was to evaluate the effect of adding different concentrations of LC during porcine invitro maturation on embryo quality and development. The cumulus–oocyte complexes were obtained by follicular aspiration from ovaries of slaughtered sows and matured invitro for 44h without LC (control) or with different concentrations of LC (0.6 or 1.25mg mL−1) (Sigma-Aldrich) in TCM-199 supplemented with human menopausal gonadotrophin and cyclic AMP (cAMP) during the first 22h. Invitro fertilization was performed with fresh boar semen for 4h in 100-µL drops of TCM-199 with caffeine, bovine serum albumin, sodium lactate, and pyruvate (20 denuded oocytes per drop, 1×106 spermatozoa mL−1). Presumptive zygotes were washed and cultured in NCSU 23 at 39°C, 7% O2, 5% CO2, and humidity. The cleavage rate was registered on Day 2 and the blastocyst rate on Day 7. Embryo quality was assessed by counting the number of cells per blastocyst (Hoescht 33342) and late apoptosis index (TUNEL-positive cells/total cells). Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) was performed according to the kit protocol (Roche). LC significantly decreased the cleavage rate (control: 46.2%; LC0.6: 32.1%; LC1.25: 37.9%; P&lt;0.05, Chi-squared test). No significant differences were detected in the blastocyst rate (control: 19.2%; LC0.6: 17%; LC1.25: 10,2%, Chi-squared test) or in number of cells per blastocyst (control: 51.97±3; LC0.6: 56.11±4; LC1.25: 45.62±4, ANOVA). There was embryo hatching in LC treatments but not in the control (control: 0%, LC0.6: 11%; LC1.25: 7.6%). The apoptosis index decreased in LC1.25 compared with LC0.6 (Control: 7,6±1.3%; LC0.6: 10±1.1%; LC1.25: 5,5±0.8%; P&lt;0.05, ANOVA) but there was no significant difference in the apoptosis index between control and LC treatments. In conclusion, LC treatments decreased the cleavage rate but did not modify the blastocyst rate and allowed embryo hatching.


2018 ◽  
Vol 30 (1) ◽  
pp. 175
Author(s):  
G. A. Kim ◽  
J.-X. Jin ◽  
S. Lee ◽  
A. Taweechaipaisankul ◽  
B. C. Lee

Melatonin and its metabolites are powerful antioxidants and free radical scavengers. Because porcine embryos are vulnerable to oxidative stress in vitro, the addition of various protective chemicals to the culture medium, including melatonin, has been explored. The aim of this study was to investigate the effect of melatonin on in vitro developmental competence of porcine parthenogenetically activated (PA) embryos. Immature cumulus–oocyte complexes (COC) were collected and cultured in medium comprising TCM-199 supplemented with 10 ng mL−1 epidermal growth factor, 0.57 mM cysteine, 0.91 mM sodium pyruvate, 5 μL mL−1 insulin, transferrin selenium solution 100×, 10% porcine follicular fluid, 10 IU mL−1 eCG, and 10 IU mL−1 hCG for 44 h. Then, COC were denuded and PA with electrical stimulation, and PA embryos were cultured in porcine zygote medium 5 (PZM-5) supplemented with melatonin at increased concentrations (10−9, 10−7, 10−5 M) at 39°C in a humidified atmosphere of 5% O2, 5% CO2, and 90% N2 for 7 days. Subsequent embryo development, including cleavage rate, blastocyst rate, and blastocyst cell numbers, was compared between groups (mean no. of embryos; control, 27.14; 10−9 M, 28.86; 10−7 M, 27.71; 10−5 M, 26.43). The experiments were repeated 7 times for each treatment group. Statistical analyses of all data were performed using one-way ANOVA with Dunn’s multiple comparison test. Results are expressed as the mean ± SEM and all differences were considered significant at P < 0.05. No apparent effect on cleavage rate of melatonin treatment of various concentrations was noted. Blastocyst cell number did not show any significant difference between groups. However, the potential of PA oocytes to develop into blastocysts was significantly higher in the group supplemented with 10−9 M melatonin compared with the control group (35.44 ± 3.84 v. 24.71 ± 1.59) and other melatonin treated groups (10−5 M, 21.35 ± 2.82; 10−7 M, 24.01 ± 2.31; P < 0.05). These indicated that treatment with 10−9 M melatonin in embryo culture might reduce the oxidative stress properly compared with other concentrations, which results in improvement of blastocyst rate formation. In conclusion, treatment with 10−9 M melatonin positively promoted the blastocyst formation rate of porcine PA embryos with no beneficial effects on their blastocyst cell numbers or cleavage rate. This study was supported by the National Research Foundation (#2015R1C1A2A01054373; 2016M3A9B6903410), Research Institute for Veterinary Science and the BK21 PLUS Program.


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