138 DEVELOPMENTAL COMPETENCE OF BIOPSIED AND SPLIT BOVINE EMBRYOS

2015 ◽  
Vol 27 (1) ◽  
pp. 161
Author(s):  
M. Reichenbach ◽  
S. Jung ◽  
R. Fries ◽  
E. Wolf ◽  
C. Gschoederer ◽  
...  

The aim of the present study was to develop a reliable method to simultaneously split and biopsy valuable bovine embryos for a complete genomic evaluation (gender, polledness, and hereditary abnormalities) and to estimate the breeding value of progeny for traits of economic importance immediately after embryo recovery. A total of 208 good quality embryos collected from superovulated German Simmental animals were biopsied immediately after recovery using an inverse microscope (Zeiss, Germany) at 50× magnification with a single-use steel blade mounted on a holder (Bausch & Lomb, Germany) attached to a micromanipulator (Eppendorf, Germany). Biopsy was performed either by splitting the embryo and cutting of one-third of a half [G1: morulae (M), n = 50; early blastocysts (EB), n = 24; blastocysts (B), n = 16], by just splitting in equal halves (G2: M, n = 16; B, n = 2), or by cutting of just a small biopsy of the embryo (G3: M, n = 53) or of the trophoblast (G3: EB, n = 19; B, n = 28). Biopsied cells were immediately used for DNA amplification. Biopsied embryos (E) and demi-embryos (DE) were in vitro cultured in SOF, under mineral oil, at 39°C and 5% CO2, 5% O2, 90% N2 for 24 h, after which survival was recorded. Survival rate of G1 (survival of at least 1 DE: M, 98.0%; EB, 100.0%; B, 93.8%), G2 (survival of DE: M, 75.0%; B, 100.0%), and G3 (embryo survival: M, 96.3%; EB, 100.0%; B, 96.4%) were similar, but in relation to the number of original embryo the highest ratio of DE was obtained in G1 (1.67) v. G2 (0.88) and G3 (0.97; G1:G2/G3; P < 0.01). Within G1, the highest ration to the original number of embryos was by using M (1.78), followed by EB (1.75) and B (1.19; M/EB:B; P < 0.05). To verify the viability of biopsied embryos some DE from G1 (1, the nonbiopsied DE, n = 7, or 2, the biopsied and the nonbiopsied DE per recipient, n = 21), G2 (1 DE per recipient, n = 13), and G3 (1 E per recipient, n = 8) were transferred after 24 h of culture. Overall pregnancy rate (Day 42) of G1, G2, and G3 was 64.3, 23.1, and 50.0%, respectively (G1 : G2; P < 0.05). In G1, pregnancy rates (Day 42) of biopsied embryos differed significantly if either 1 or 2 DE were transferred per recipient (28.6 v. 76.2%, respectively; P < 0.05). A twin pregnancy rate of 38.9% was observed by ultrasonography in recipients when 2 DE were transferred. The results suggest that high survival rates can be obtained with the G1 technique, and splitting during biopsy can increase productivity in programs aimed to evaluate the genomic constitution of early stage embryos. Funded by the Bayerische Forschungsstiftung (AZ-1031-12).

2005 ◽  
Vol 17 (2) ◽  
pp. 199 ◽  
Author(s):  
B. Peachey ◽  
K. Hartwich ◽  
K. Cockrem ◽  
A. Marsh ◽  
A. Pugh ◽  
...  

Vitrification has become the method of choice for the preservation of in vitro derived embryos of a number of species, and several methods of vitrification have been developed. One such method, the cryoLogic vitrification method (CVM) yields high survival rates of warmed embryos (Lindemans W et al. 2004 Reprod. Fertil. Dev. 16, 174 abst). In this study, the post-warm viability of bovine IVP embryos following either vitrification using CVM or slow freezing using ethylene glycol (EG) was compared. In addition, the survival of embryos following triple transfer to synchronized recipients was measured and the embryo (“e”) and recipient (“r”) contributions to embryo survival was determined using the “er” model for embryo survival (McMillan WH et al. 1998 Theriogenology 50, 1053–1070). Bovine IVP methods were those of van Wagtendonk et al. 2004 Reprod. Fertil. Dev. 16, 214 (abst). On day 7 of culture (Day 0 = IVF), Grade 1 and 2 embryos that had reached at least the late morula stage were selected for vitrification (20% DMSO, 20% ethylene glycol) or freezing in 1.5 M ethylene glycol + 0.1 M sucrose (0.5°C/min to −35°C). Following storage in LN2 for at least 24 h the embryos were thawed, the cryoprotectant removed, and the embryos cultured for 72 h in mSOF medium under 5% CO2, 7% O2, 88% N2. The number of hatching embryos was recorded at 24-h intervals. In addition, blastocyst and expanded blastocyst embryos were thawed and immediately transferred nonsurgically to recipients (three embryos of the same grade to each recipient) on Day 7 of a synchronized cycle (Day 0 = heat). The recipients were ultrasound-scanned for the presence of, and number of, fetuses on Days 35 and 62, respectively. The invitro assessment of 148 CVM and 230 EG frozen embryos indicated that more vitrified than EG embryos hatched by 72 h (73% vs. 62%; CVM vs. EG, χ2 = 4.5, P < 0.05). Overall, more Grade 1 embryos hatched than Grade 2 (74% vs. 60%, χ2 = 7.2, P < 0.01). CVM embryos (105) were triple-transferred to 35 recipients, and EG embryos (30) were triple-transferred to 10 recipients. Recipient pregnancy rates at Day 62 were 80% and 70%, respectively. Overall embryo survival was 38.5% (41% for CVM and 30% for EG). The overall calculated “e” and “r” values were 0.39 and 1.0 (“e”: 0.42 and 1.0, and “r”: 0.31 and 1.0, respectively, CVM and EG groups). Survival rates of CVM embryos to Day 62 (41%) were slightly lower than that previously obtained for fresh embryos produced using an identical IVP procedure (44% – van Wagtendonk AM 2004).


2004 ◽  
Vol 16 (2) ◽  
pp. 213 ◽  
Author(s):  
J. Small ◽  
M. Colazo ◽  
D. Ambrose ◽  
R. Mapletoft ◽  
J. Reeb ◽  
...  

The objective was to evaluate the effect of pLH treatment on pregnancy rates in recipients receiving in vivo- or in vitro-produced bovine embryos. Heifers (n=37) and lactating (n=28) and non-lactating (n=150) beef cows were treated at random stages of the cycle with 100μg GnRH i.m. (Cystorelin, Merial Canada Inc., Victoriaville, Quebec, Canada) on Day −9, 500μg cloprostenol i.m. (PGF; Estrumate, Schering Plough Animal Health, Pointe-Claire, Quebec, Canada) on Day —2 and GnRH on Day 0 (66h post-PGF; without estrus detection). Cattle were placed at random, by class, into three groups: no further treatment (Control; n=71), or 12.5mg pLH (Lutropin-V, Bioniche Animal Health, Belleville, Ontario, Canada) on Day 5 (n=72) or on Day 7 (n=72) after the second GnRH. On Day 7, cattle with a CL &gt;10mm in diameter (determined ultrasonically) received in vivo-produced, fresh (Simmental) or frozen (Holstein), or in vitro-produced frozen (Holstein) embryos (embryo type balanced among groups). Embryos were cryopreserved in 10% ethylene glycol; in vivo-produced frozen embryos were thawed 5 to 10s in air, 15s in a water-bath at 30°C and then “direct-transferred” nonsurgically. In vitro-produced frozen embryos (donated by IND Lifetech Inc., Delta, British Columbia, Canada) were thawed in a water-bath at 27°C for 10s and placed in ViGro Holding Plus medium (AB Technology, Pullman, WA, USA) at room temperature, evaluated and then transferred nonsurgically. Pregnancy was determined by ultrasonography on Day 35. Data were analyzed with CATMOD, chi-square and GLM procedures (SAS Institute, Cary, NC, USA.). Twenty cattle (9.3%) did not receive embryos; five heifers had cervical problems, and five heifers and 10 cows did not have a CL &gt;10mm. Overall, 7.1% of the recipients had two CL on the day of embryo transfer. There was no effect (P&gt;0.05) of treatment, embryo type (or interaction) or class of recipient on pregnancy rate (overall, 44.1%, 86/195; Table 1). Similarly, mean (±SD) CL diameter and luteal area did not differ (P&gt;0.05) among groups or between pregnant and open recipients (overall, 22.0±3.4mm and 352.0±108.7mm, respectively). However, recipients with a CL diameter ≥18mm tended (P&lt;0.1) to have a higher pregnancy rate (45.8 vs 25.0%). In a subset of 40 recipients examined ultrasonically on Day 12, 50% of those treated on Day 5 and 70% of those treated with pLH on Day 7 had two CL. In summary, overall pregnancy rate in GnRH-synchronized recipients receiving in vitro- or in vivo-produced embryos by nonsurgical transfer was 44.1%. Embryo survival to Day 35 was not affected by type of embryo or treatment with pLH 5 or 7 days after ovulation. Table 1 Pregnancy rate in recipients on Day 35 based on pLH treatment and embryo-type


Author(s):  
Sergio Ledda ◽  
Jen M. Kelly ◽  
Stefano Nieddu ◽  
Daniela Bebbere ◽  
Federica Ariu ◽  
...  

Abstract Background To advance the use of embryo vitrification in veterinary practice, we developed a system in which embryo vitrification, warming and dilution can be performed within a straw. Ovine in vitro produced embryos (IVEP) were vitrified at either early (EBs: n = 74) or fully expanded blastocyst stage (FEBs: n = 195), using a new device named “E.Vit”, composed by a 0.25-mL straw with a 50-μm pore polycarbonate grid at one end. Embryos at each stage (EBs and FEBs) were vitrified by either Two-step (TS) or Multi-step (MS; 6 different concentrations of vitrification solutions) protocol. Non-vitrified embryos (n = 102) were maintained in in vitro culture as a control. Warming consisted of placing the straws directly into 1.5 mL tubes containing a TCM-199 solution with three decreasing concentrations of sucrose. Blastocyst re-expansion, embryo survival and hatching rate were evaluated at 2, 24 and 48 h post warming. The number of apoptotic cells was determined by TUNEL assay. Results Blastocyst re-expansion (2 h) after warming was higher (P < 0.05) in FEBs group, vitrified with the MS and TS methods (77.90% and 71.25%, respectively) compared with the EBs group (MS: 59.38% and TS: 48.50%, respectively). Survival rates of vitrified FEBs after 24 h IVC were higher (P < 0.001) in both methods (MS and TS) than vitrified EBs (MS: 56.25%; TS: 42.42%) and was higher (P < 0.05) in the MS method (94.19%) compared with those in TS (83.75%). After 48 h of culture the hatching rate for FEBs vitrified in MS system (91.86%) was similar to control (91.89%), but higher than FEB TS (77.5%) and EBs vitrified in MS (37.5%) and TS (33.33%). Number of apoptotic cells were higher in EBs, irrespective of the system used, compared to FEBs. The number of apoptotic cells in FEBs vitrified with MS was comparable to the control. Conclusions A high survival rate of IVP embryos can be achieved by the new “E.Vit” device with hatching rates in vitro comparable with control fresh embryos. This method has the potential for use in direct embryo transfer in field conditions.


2008 ◽  
Vol 20 (1) ◽  
pp. 147
Author(s):  
J. E. Park ◽  
G. Jang ◽  
H. J. Oh ◽  
S. G. Hong ◽  
I. S. Yang ◽  
...  

During the preimplantation stage, embryo development occurs in a maternal environment within the oviducts and uterine horns. It has been speculated that both the embryo itself and the maternal reproductive tract provide paracrine factors that influence embryo development (Jones et al. 2006 Reproduction 132(5), 799–810). Activins are known for FSH releasers, and several previous studies have reported that activin subunits and activin receptors mRNA were expressed in oocytes, zygotes, and oviduct (Yoshioka et al. 1998 Reprod. Fertil. Dev. 10(3), 293–298; Gandolfi et al. 1995 Mol. Reprod. Dev. 40(3), 286–291). The purposes of the present study were Experiment 1) to evaluate the effects of activin A on developmental competence of bovine embryos derived from two-step defined culture medium (Lim et al. 2007 Theriogenology 67(2), 293–302) and Experiment 2) to analyze the effects of activin A on transcriptional level of the genes in IVF embryos. Cumulus–oocyte complexs were harvested from ovaries obtained from a local slaughter house, matured, and fertilized in vitro. In vitro fertilized zygotes cultured in media supplemented with activin A in the early stage at the concentrations of 0, 10, or 100 ng mL–1 or in the later stage medium at the concentrations of 0, 10, or 100 ng mL–1. Data were analyzed using the Statistical Analysis System (SAS) program. In Exp. 1, although the development competence of embryos that cultured with activin A in the early stage medium was not significantly different, development to blastocysts on day 8 in the later stage medium with 100 ng mL–1 activin A was significantly higher than the control group [22.4% (54/264) v. 34.7% (76/233); P < 0.05]. Hatching rate of blastocyst on day 8 was significantly higher in the presence of 100 ng mL–1 activin A in the later stage culture medium compared with the control group [9.3% (5/54) v. 22.4% (17/76); P < 0.05]. In Exp. 2, the relative expression of 3 genes (Na/KATPase, E-cad, Glut-1) related to blastocyst hatching and implantation was analyzed. The relative abundance (ratio to GAPDH mRNA) of gene transcripts in blastocysts was measured by conventional semi-quantitative reverse transcription-polymerase chain reaction. The expression level of the Na/K ATPase, E-cad, and Glut-1 gene were higher in the presence of activin A in the culture medium compared with the control group. In conclusion, this study suggests that activin A during the later stage of in vitro bovine embryo development can enhance the developmental competence of preimplantation embryos, increase the hatching rate, and affect expression level of genes related to hatching and implantation in defined culture medium. This study was financially supported by KOSEF (grant ? M10625030005-07N250300510) and the Korean MOE, through the BK21 program for Veterinary Science.


2019 ◽  
Vol 31 (1) ◽  
pp. 137
Author(s):  
T. Fujikawa ◽  
Y. Gen ◽  
S.-H. Hyon ◽  
C. Kubota

Carboxylated poly-l-lysine (CPLL) is an ampholytic polymer compound and a polyamino acid with a known functional resemblance to antifreeze proteins. We previously reported that CPLL is an effective cryoprotectant for bovine cells, sperm, and slow-frozen embryos. In this study, we investigated CPLL as a cryoprotectant for vitrified bovine embryos. We developed bovine embryos in vitro and vitrified them at the blastocyst stage. Embryos were equilibrated (3min) and vitrified (1min). Vitrified embryos were cryopreserved in LN (Cryotop® device; Kitazato Corp., Tokyo, Japan) for at least 1 week, thawed with a 0.3M sucrose warming solution, and then cultured in a basal medium (Gibco® medium 199, Grand Island, NY, USA; supplemented with 100µM 2-mercaptoethanol, 10% fetal bovine serum, and antibiotics) at 38.5°C in a humidified atmosphere (5% CO2, 5% O2, 90% N2). We evaluated the embryos morphologically for survival and hatched rate at 0, 24, 48, and 72h post-thawing. In control, the equilibration solution (ES) consisted of 7.5% (vol/vol) dimethyl sulfoxide (DMSO) and 7.5% (vol/vol) ethylene glycol, and the vitrification solution (VS) consisted of 16.5% (vol/vol) DMSO and 16.5% (vol/vol) ethylene glycol and 0.5M sucrose. In this study, CPLL was added to ES and VS at various concentrations instead of DMSO. The CPLL was added at 16.5, 11.0, 5.5, and 2.2% (wt/vol) to VS; respectively, these solutions were named P16.5, P11.0, P5.5, and P2.2. The ES was used 45% CPLL of VS each. Embryos underwent the above procedure concurrently, with testing replicated at least 3 times. We evaluated 88, 34, 38, 44, and 28 embryos with each solution (control, P16.5, P11.0, P5.5, and P2.2, respectively). Results were analysed statistically with a chi-square test and residual analysis, regarding P&lt;0.05 as significant. Survival rates were significantly greater in P11.0 at 24h post-thawing (55.7% v. 89.5%; P&lt;0.05) and in P11.0 and P5.5 at 48h post-thawing (47.7% v. 78.9% and 47.7% v. 79.5%, respectively; P&lt;0.05) relative to controls but showed no significant differences at 0h post-thawing. Hatched rates were significantly greater in P11.0 and P5.5 through 72h post-thawing relative to controls (44.7% v. 22.7% and 52.3% v. 22.7%, respectively; P&lt;0.05). The CPLL improved post-thawing embryo survival and hatched rates when applied during vitrification, thus demonstrating cryoprotective effectiveness. We conclude that CPLL acts as a low-toxicity cryoprotectant for vitrified bovine embryos, and our results are consistent with previous reports of protective CPLL effects for cells and cell membranes.


2004 ◽  
Vol 16 (2) ◽  
pp. 172 ◽  
Author(s):  
J.M. Kelly ◽  
D.O. Kleemann ◽  
M. Kuwayama ◽  
S.K. Walker

Considerable progress has been achieved in the cryopreservation of mammalian embryos. The use of vitrification minimizes chilling injuries by increasing cooling and warming rates. This study assesses the effect of vitrification using the minimum volume cooling (MVC) method (Kuwayama &amp; Kato 2000 J. Assist. Reprod. Genet. 17, 477) on in vitro-produced bovine and ovine embryos. A total of 1756 ovine and 753 bovine cumulus-oocyte complexes were obtained from the abattoir and matured, fertilized (Day 0) and cultured in vitro (Walker et al., 1996 Biol. Reprod. 55, 703–708, Kelly et al., 1997 Theriogenology 47, 291). Overall cleavage rates were 93.7% and 80.5% respectively. Embryos were vitrified (OPS or MVC method) on Days 5 (morula, compact morula), 6 (expanded blastocyst, blastocyst, compact morula) or 7 (hatched and hatching blastocysts, expanded blastocyst, blastocyst). Embryos were equilibrated with 7.5% ethylene glycol (EG) and 7.5% dimethyl sulfoxide (DMSO) for 3min and then exposed to 16.5% EG, 16.5% DMSO, 0.5M sucrose and 20% FCS for 30s. Embryos were loaded onto either an MVC plate (Cryotop, Kitazato Supply Co, Toyko, Japan) or open pulled straw (OPS) and plunged into liquid nitrogen. After 5 days, embryos were thawed directly into 1.25M sucrose solution at 38.5°C, followed by stepwise dilution of the cryoprotectants. Embryo survival was assessed by culture to Day 8 and compared to the development of non-vitrified control embryos (Table 1). Variables were assessed using procedure CATMOD in SAS. The Cryotop method yielded a significantly higher percentage of viable ovine embryos after thawing compared with OPS (P&lt;0.0001); neither day nor treatment x day interaction was significant (P&gt;0.05). A significant interaction between vitrification treatment and day (P&lt;0.007) indicated that the percentage of hatched embryos peaked at Day 6 using the Cryotop method compared with Day 7 for OPS. Hatching rates for fresh and vitrified embryos were similar at Day 7 and were independent of treatment. With the Cryotop method, day of vitrification did not influence the percentage of Days 6 and 7 bovine embryos that hatched after thawing but, on each day, this figure was significantly higher (P&lt;0.003 and P&lt;0.0001, respectively) than that obtained with fresh embryos. To further assess embryo viability, 36 fresh, 52 OPS and 56 Cryotop vitrified Day-6 in vitro-produced ovine embryos were transferred to synchronized recipients. Survival rates to Day 13 were 29/33 (87.9%), 23/36 (63.9%) and 42/51 (82.4%), respectively (P&lt;0.05). This study demonstrates that using the MVC Cryotop method, the viability of vitrified embryos, as assessed at Days 8 and 13, is similar to that obtained with fresh embryos. Table 1


2021 ◽  
Vol 8 ◽  
Author(s):  
Cristina Cuello ◽  
Cristina A. Martinez ◽  
Josep M. Cambra ◽  
Alejandro González-Plaza ◽  
Inmaculada Parrilla ◽  
...  

Despite the reported promising farrowing rates after non-surgical and surgical transfers of vitrified porcine morulae and blastocysts produced in vivo (range: 70–75%), the pregnancy loss is 5–15 fold higher with vitrified than with fresh embryos. The present study aimed to investigate whether vitrification affects the transcriptome of porcine morulae, using microarrays and RT-qPCR validation. Morulae were obtained surgically from weaned sows (n = 13) on day 6 (day 0 = estrus onset). A total of 60 morulae were vitrified (treatment group). After 1 week of storage, the vitrified morulae were warmed. Vitrified-warmed and non-vitrified fresh morulae (control; n = 40) were cultured for 24 h to assess embryo survival by stereomicroscopy after. A total of 30 vitrified/warmed embryos that were deemed viable and 30 fresh control embryos (three pools of 10 for each experimental group) were selected for microarray analysis. Gene expression was assessed with a GeneChip® Porcine Genome Array (Affymetrix). An ANOVA analysis p-unadjusted &lt;0.05 and a fold change cut-off of ±1.5 were set to identify differentially expressed genes (DEGs). Data analysis and biological interpretation were performed using the Partek Genomic Suite 7.0 software. The survival rate of morulae after vitrification and warming (92.0 ± 8.3%) was similar to that of the control (100%). A total of 233 DEGs were identified in vitrified morulae (38 upregulated and 195 downregulated), compared to the control group. Nine pathways were significantly modified. Go-enrichment analysis revealed that DEGs were mainly related to the Biological Process functional group. Up-regulated DEGs were involved in glycosaminoglycan degradation, metabolic pathways and tryptophan metabolism KEGG pathways. The pathways related to the down-regulated DEGs were glycolysis/gluconeogenesis, protein export and fatty acid elongation. The disruption of metabolic pathways in morulae could be related to impaired embryo quality and developmental potential, despite the relatively high survival rates after warming observed in vitro. In conclusion, vitrification altered the gene expression pattern of porcine morulae produced in vivo, generating alterations in the transcriptome that may interfere with subsequent embryo development and pregnancy after embryo transfer.


2004 ◽  
Vol 16 (2) ◽  
pp. 182
Author(s):  
B. Shangguan ◽  
N. Yang ◽  
R. Vanderwal ◽  
M.D. Darrow

Arabinogalactan (AG) in combination with 1.5M ethylene glycol (EG) has been used successfully in cryopreserving biopsied in vivo bovine embryos (Darrow, 2002 Theriogenology 57(1), 531). This study was undertaken to investigate the efficiency of AG addition in a freezing medium (FM) to cryopreserve biopsied bovine embryos produced in vitro (IVP). Blastocysts of grade 1 were collected at Days 7 and 8 post-insemination. After biopsy with a small blade, embryos were transferred to CR1aa medium and cultured for 2 hours (h) before being frozen. In experiment 1, a group of unbiopsied embryos were handled in a manner similar to that used for the biopsied embryos. Embryos were frozen using either 1.5M EG+0.1M sucrose (EG+) (AB Technology, Pullman, WA, USA) or a FM containing 1.5M EG and different concentrations of AG (AG1, 2 and 3, courtesy of AB Technology). Embryos remained in FM for 10 (exp.1), 5 (exp.2), 5 and 10 (exp.3) or 5, 10, and 20 (exp.4) minutes before being loaded into a freezer and cooled down to −35°C at 0.3°C/min. Frozen embryos were thawed (35°C, 20 seconds) and cultured in CR1aa at 38.5°C for 3 days. Embryo survival rates (S%) were recorded at 24, 48 and 72h post-thawing. Data were compared with t-test or ANOVA procedures using SigmaStat 3.0. Results from exp.1 (Table) indicate that biopsied and unbiopsied embryos survived well in EG+ or AG2. While the biopsy procedure did not affect the post-thaw S% of embryos in either FM, no significant differences were observed between embryos frozen with EG+ and AG2 (P=0.055). Reducing or increasing AG concentration in FM by 2-fold (AG1 and 3, respectively) did not significantly affect the post-thaw S% at 24h (EG+, 80.0%, n=133; AG1, 83.3%, n=135; AG2, 71.4%, n=137 and AG3, 75.0%, n=135; P=0.217, exp.2). However, shortened exposure from 10 to 5 minutes to AG2 resulted in an improvement in S% at 24h, from 35.7% (n=80) to 61.4% (n=82, P&lt;0.05; exp.3). When AG1 (=0.5×AG2) was used in the FM the S% at 24h after different exposure times was not significant (5 minutes, 77.8%, n=179; 10 and 20 minutes, 66.7%, n=179 and 183; P=0.472, exp.4). This study demonstrates that addition of AG to the FM effectively sustains the viability of biopsied IVP embryos during freezing and any potential harmful impact of AG on embryo survival can be minimized by reducing AG concentration or the time of embryo exposure to AG prior to freezing. Further studies are needed to determine optimal AG concentration. Currently, field trials are underway to evaluate the ability of AG medium to promote pregnancies from frozen, biopsied IVP embryos. Table 1 Post-thaw survival rates of biopsied IVP embryos frozen in ethylene glycol with sucrose (EG+) and a FM containing arabinogalactan (AG2). Data are means±SEM


Zygote ◽  
2020 ◽  
pp. 1-5
Author(s):  
Li Ang ◽  
Cao Haixia ◽  
Li Hongxia ◽  
Li Ruijiao ◽  
Guo Xingping ◽  
...  

Summary The present study investigated the effects of c-type natriuretic peptide (CNP) on the development of murine preantral follicles during in vitro growth (IVG). Preantral follicles isolated from ovaries of Kunming mice were cultured in vitro. In the culture system, CNP was supplemented in the experimental groups and omitted in the control groups. In Experiment 1, CNP was only supplemented at the early stage and follicle development was evaluated. In Experiments 2 and 3, CNP was supplemented during the whole period of in vitro culture. In Experiment 2, follicle development and oocyte maturity were evaluated. In Experiment 3, follicle development and embryo cleavage after in vitro fertilization (IVF) were assessed. The results showed that in the control groups in all three experiments, granulosa cells migrated from within the follicle and the follicles could not reach the antral stage. In the experimental groups in all three experiments, no migration of granulosa cells was observed and follicle development was assessed as attaining the antral stage, which was significantly superior to that of the control group (P < 0.0001). Oocyte meiotic arrest was effectively maintained, hence giving good developmental competence. In conclusion, CNP supplementation in the culture system during IVG benefited the development of murine preantral follicles.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 860
Author(s):  
Wu-Sheng Sun ◽  
Hoon Jang ◽  
Mi-Ryung Park ◽  
Keon Bong Oh ◽  
Haesun Lee ◽  
...  

Oxidative stress has been suggested to negatively affect oocyte and embryo quality and developmental competence, resulting in failure to reach full term. In this study, we investigated the effect of N-acetyl-L-cysteine (NAC), a cell-permeating antioxidant, on developmental competence and the quality of oocytes and embryos upon supplementation (0.1–10 mM) in maturation and culture medium in vitro using slaughterhouse-derived oocytes and embryos. The results show that treating oocytes with 1.0 mM NAC for 8 h during in vitro maturation attenuated the intracellular reactive oxygen species (ROS) (p < 0.05) and upregulated intracellular glutathione levels (p < 0.01) in oocytes. Interestingly, we found that NAC affects early embryonic development, not only in a dose-dependent, but also in a stage-specific, manner. Significantly (p < 0.05) decreased cleavage rates (90.25% vs. 81.46%) were observed during the early stage (days 0–2), while significantly (p < 0.05) increased developmental rates (38.20% vs. 44.46%) were observed during the later stage (from day 3) of embryonic development. In particular, NAC supplementation decreased the proportion of apoptotic blastomeres significantly (p < 0.05), resulting in enhanced hatching capability and developmental rates during the in vitro culture of embryos. Taken together, our results suggest that NAC supplementation has beneficial effects on bovine oocytes and embryos through the prevention of apoptosis and the elimination of oxygen free radicals during maturation and culture in vitro.


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