Effect of duration of сycloheximide and 6‐dimethylaminopurine (6‐DMAP) treatments on development competence of cloned embryos in cattle

2021 ◽  
pp. 85-91
Author(s):  
E. Shedova ◽  
A. Lopukhov
Keyword(s):  
Apoptotic Cell ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Total Cell ◽  
Negative Consequences ◽  
Cleavage Rate ◽  
Total Cell Number ◽  
Wide Range ◽  
Definition Of

Cycloheximide and 6‐dimethylaminopurine (6‐DMAP) are widely used in protocols of somatic cell nuclear transfer (SCNT) for inhibition of maturation promoting factor (MPF) activity in SCNT-oocytes in the post-activation period of their culture. Nevertheless, you should remember that these agents have a wide range of activity and can conflict with other cell processes. Therefore, a definition of the optimal period of culture of SCNT-oocytes with the previously mentioned inhibitors may help to prevent the undesirable negative consequences. In this research the effects of cycloheximide (10 µg/ml) and 6‐DMAP (2mM) treatments duration (3.0, 4.0 or 5.0 h) on the reprogramming of somatic nuclear was estimated by the cleavage and blastocyst rates, and by the total cell number and a level of apoptotic cell in the obtained cloned blastocysts. The cleavage rate did not differ between the experimental groups, varying from 63.7 to 77.0 %. Also, there was not found an effect of treatment duration of the investigated factors on the development of activated SCNT-oocytes before blastocyst stage. For 3-hr treatment, the blastocyst rate was 19.6 ± 1.8%. The prolonged up to 4 and 5 hours duration did not change this rate. Meanwhile, we found out the effect of culture duration with сycloheximide and 6‐DMAP on quality of cloned embryos. In case of 3-hr treatment, the total cell number in cloned blastocyst was 58.8 ± 2.4. With prolongation of duration up to 4 hours the result was growing up to 76.6 ± 1.4 (p<0.05), but prolongation up to 5 hours reduced the total cell number in blastocyst as compared to that in 4-hr group (p<0.05). The apoptosis rate had no difference between the treated groups and had its variety between 5.4 to 7.0 %. Our date indicate that efficiency of bovine cloned embryo production depends on duration of 6-DMAP and cycloheximide treatment of the SCNT-oocytes in the post-activated period of their culture. The optimal duration according to the described protocol of SCNT for the best quality of embryos is 4 hours.

147 QUALITY OF PORCINE EMBRYOS CULTURED WITH HYALURONAN

2010 ◽  
Vol 22 (1) ◽  
pp. 232
Author(s):  
B. Gajda ◽  
I. Grad ◽  
E. van der Tuin ◽  
Z. Smorag
Keyword(s):  
Cell Number ◽  
Blastocyst Stage ◽  
Apoptotic Index ◽  
Total Cell ◽  
Total Cell Number ◽  
Developmental Potential ◽  
Group 2 ◽  
Group 1

Hyaluronan (HA) is a high molecular weight polysaccharide found in the mammalian follicular, oviduct, and uterine fluids. When HA is added in maturation and culture media, it improves the developmental potential of bovine (Stojkovic M et al. 2002 Reproduction 124, 141-153; Palasz AT et al. 2008 Zygote 16, 39-47), and porcine oocytes (Sato E et al. 1990 Mol. Reprod. Dev. 26, 391-397) and embryos (Miyano T et al. 1994 Theriogenology 41, 1299-1305). Physiological concentration of HA in follicular, oviductal, and uterine fluids of pigs range from 0.04 to 1.83 mg mL-1 (Kano K et al. 1998 Biol. Reprod. 58, 1226-1232). The aim of the present study was to investigate the effect of different concentrations of HA on the development and quality of cultured porcine embryos. Zygotes from superovulated pigs were cultured in vitro in NCSU-23 medium supplemented with BSA and 0 mg mL-1 (control group), 0.25 mg mL-1 (Exp. Group 1), and 0.5 mg mL-1 (Exp. Group 2) of HA (Animal Pharma BV). Experiments were replicated 3 times with 30 to 40 embryos per each treatment group. Embryos were cultured up to the blastocyst stage at 39°C in an atmosphere of 5% CO2 in air, in 4-well plastic dishes, which contained approximately 0.8 mL of the NCSU-23 medium. Embryo quality criteria were cleavage (on Day 2 after in vitro culture), morula (on Day 4) and blastocyst (on Days 6 to 8) rates, total cell number per blastocyst, and degree of apoptosis (on Day 7) assessed by TUNEL method. Results were analyzed by ANOVA test. There was no difference in percentage of cleaved embryos between control and treated Group 1 and 2.The proportion of embryos developed to the morula and blastocyst stage was 80.0 and 60.0% for Group 1 (0.25 mg of HA), 73.7 and 44.7% for Group 2 (0.5 mg of HA), and 73.4 and 46.7% for control, respectively (difference NS). Supplementation with HA did not increase the cell number of the blastocysts but significantly reduced number of apoptotic nuclei from 2.0 for control to 0.7 (P < 0.01) and 0.6 (P < 0.01) for Group 1 and 2, respectively, and apoptotic index from 9.70 for control to 3.01 (P < 0.05) and 1.95 (P < 0.05) for Group 1 and 2, respectively. These results indicate that supplementation of culture medium NCSU-23 with HA improves the quality (assessed by apoptotic index) of pig embryos but does not increase the total cell number in pig blastocysts as reported by Kim HS et al. 2005 (Theriogenology 63, 1167-1180). However, further research to test the HA’s effect on cryopreservation of in vitro and in vivo produced pig embryos are needed.

PSX-B-11 Comparing effects of FGF2 and IGF1 on the development competence of parthenogenetic activated bovine oocytes maturing in vitro

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 327-328
Author(s):  
Galina Singina
Keyword(s):  
Growth Factor ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Total Cell ◽  
Control Group ◽  
Total Cell Number ◽  
Developmental Potential ◽  
Maturation Medium ◽  
Bovine Oocytes

Abstract The oocyte quality acquired during in vitro maturation (IVM) are the main limitative factors affecting the embryo production. The aim of the present research was to study effects of fibroblast growth factor 2 (FGF2) and insulin-like growth factor 1 (IGF1) during IVM of bovine oocytes on their developmental potential after parthenogenetic activation. Bovine cumulus-oocyte complexes (COC; n = 1176) were cultured for 22h in either standard maturation medium (TCM-199 supplemented with 10% fetal calf serum (FCS), 0.2 mM sodium pyruvate, 10 μg/ml FSH and 10 μg/ml LH; Control) or maturation medium supplemented with different concentrations (5–160 ng/ml) of FGF2 and IGF1. After IVM, matured oocytes activated by sequential treatment with ionomycin followed by DMAP and cyclohexamide and then cultured up to the blastocyst stage. The obtained blastocysts were fixed, and the total cell number and the level of apoptosis were determined using DAPI and TUNEL staining. The data from 4 replicates (77–91 oocytes per treatment) were analyzed by ANOVA. Cleavage rates of activated oocytes did not differ between groups and ranged from 63.7 to 68.1%. The addition of 10, 20 and 40 ng/ml of FGF2 to the IVM medium led to an increase in the yield of blastocysts [from 19.6±1.8% (Control) to 35.2±3.4, 29.8±1.9 and 31.1±2.1%, respectively (P&lt;0.05)] and in the total cell number in embryos that developed to the blastocyst stage (P&lt;0.05). Meanwhile, the blastocyst yield and the total cell number in blastocysts in the IGF1-treated groups were similar to that in the control group. No effects of both growth factors on the proportion of apoptotic nuclei in blastocysts (5.3–7.1%) were observed. Thus, FGF2 (but not IGF1) are able to maintain competence for parthenogenetic development of bovine COC during their maturation invitro. Supported by RFBR (18-29-07089) and the Ministry of Science and Higher Education of Russia.

155 QUALITY OF PORCINE EMBRYO PRODUCED IN TWO EMBRYO CULTURE MEDIA AS ASSESSED BY TOTAL CELL NUMBER AND TIME COURSE OF BLASTOCYST HATCHING

2006 ◽  
Vol 18 (2) ◽  
pp. 185 ◽  
Author(s):  
Y. Agca ◽  
H. Men ◽  
S. F. Mullen ◽  
L. K. Riley ◽  
R. S. Prather ◽  
...  
Keyword(s):  
Embryo Culture ◽  
Time Course ◽  
Culture Media ◽  
Cell Number ◽  
Total Cell ◽  
Total Cell Number ◽  
Blastocyst Hatching ◽  
Hatching Rates

The ability to produce porcine embryos of good quality will have a significant impact on a number of porcine assisted reproductive technologies, such as cloning, intracytoplasmic sperm injection, and embryo cryopreservation. However, porcine embryos resulting from current serum-free embryo culture systems differ significantly both structurally and functionally from those derived in vivo (Wang et al. 1999 Mol. Reprod. Dev. 53, 99-107). In this experiment, the quality of porcine embryos produced by North Carolina State University (NCSU)-23 medium (Petters and Wells 1993 J. Reprod. Fertil. Suppl. 1993, 48, 61-73) and porcine zygote medium (PZM)-1 (Yoshioka et al. 2002 Biol. Reprod. 66, 112-119) were compared by assessing the total cell number and the time course of in vitro blastocyst hatching. Porcine embryos were produced by in vitro maturation and fertilization using serum-free systems. After fertilization, presumptive zygotes were randomly allocated to either PZM-1 or NCSU-23 for subsequent development. On Day 4 of culture, the embryo culture media were supplemented with 10% fetal bovine serum (FBS). Day 6 blastocysts from each group were counted and the blastocysts were subsequently fixed in 4% formalin for counting the total cell number. The cell number in each embryo was determined by counting the nuclei after staining with bisbenzimide (Hoechst 33342). To assess the hatching ability of blastocysts, Day 6 blastocysts were cultured until Day 9 and hatched blastocysts were counted daily. Day 6 blastocyst rates (ratio of blastocysts to oocytes) and total cell number count were replicated three times. The time course of blastocyst hatching experiment was repeated four times. The data were analyzed using a chi-square test, Fisher's exact test, or Student's t-test. The blastocyst rate from culture in PZM-3 was 19.4 � 0.96% (mean � SEM), which was similar to that (16.7 � 3.2%) resulting from culture in NCSU-23 (P > 0.05). However, the total cell number in Day 6 blastocysts cultured in PZM-3 was significantly higher than for blastocysts cultured in NCSU-23 (57 � 3.1 vs. 46 � 1.7; P < 0.01). The total hatching rates (ratio of hatched blastocysts to total blastocysts) by Day 9 were similar between the two culture systems (50.1 � 9.1% vs. 50.7 � 4.1%; P > 0.05). However, on Day 6, 2.1% of blastocysts from PZM-3 culture hatched whereas no blastocysts from NCSU-23 culture hatched. The cumulative hatching rates from PZM-3 culture on Day 7 were significantly higher than those from NCSU-23 culture (15.1 � 3.8% vs. 2.6 � 1.1%; P < 0.01). In conclusion, these data suggest that blastocysts produced in PZM-3 medium have better quality than blastocysts produced in the NCSU-23 culture system as assessed by the total cell number and the time course of blastocyst hatching. This project was supported by a grant from the National Institutes of Health (U42 RR 018877).

171 Effect of progesterone and prolactin on the developmental competence of bovine oocytes during the terminal phase of in vitro maturation

2019 ◽  
Vol 31 (1) ◽  
pp. 210
Author(s):  
G. Singina ◽  
E. Shedova ◽  
T. Taradajnic ◽  
V. Konnova ◽  
E. Tsyndrina
Keyword(s):  
Cell Number ◽  
Total Cell ◽  
Developmental Competence ◽  
Terminal Phase ◽  
Cleavage Rate ◽  
Total Cell Number ◽  
One Step ◽  
Group 2 ◽  
The One

To date, considerable progress has been achieved in in vitro production (IVP) technologies in cattle; however, developmental potentials of oocytes matured in vitro remain low compared with in vivo-matured oocytes. Thus, a better understanding of different aspects of oocyte maturation may allow us to increase the embryo development rate. Our study was aimed to assess the effects of progesterone (P4) and prolactin (PRL) on the bovine oocyte developmental competence. Bovine cumulus-enclosed oocytes (CEO) were matured using either one-step or two-step maturation conditions. For the one-step protocol, CEO were cultured for 24h in TCM-199 supplemented with 10% fetal calf serum (FCS), 10μg mL−1 porcine FSH, and 10μg mL−1 ovine LH (standard medium). For the two-step procedure, CEO were first cultured for 16h in the standard medium (n=1263) and then transferred to 1 of 3 experimental media and cultured for additional 8h in either absence or presence of either P4 (50 ng mL−1) or bovine PRL (50ng mL−1). The 3 media tested in the two-step maturation were (1) TCM-199 containing 10% FCS (group 1), (2) TCM-199 containing 3mg mL−1 BSA (group 2), or (3) Fert-TALP medium supplemented with 6mg mL−1 BSA (group 3). Fert-TALP was selected because it can potentially be used throughout maturation and fertilization. Following in vitro maturation, all oocytes underwent an IVF/in vitro culture procedure as described previously (Singina et al. 2014 Reprod. Fertil. Devel. 26, 154). The embryo development was evaluated at Days 2 and 7 for cleavage and blastocyst rates. In addition, obtained blastocysts were fixed, and the total cell number and the level of apoptosis were determined using 4′,6-diamidino-2-phenylindole (DAPI) and TUNEL staining. The data from 4 to 5 replicates (113-159 oocytes per treatment) were analysed by ANOVA. For oocytes matured for 24h in the one-step culture, the cleavage rate, blastocyst rate, total cell number, and apoptotic nuclei per blastocyst were 66.1±1.1, 23.7±2.0, 71.4±9.1, and 4.8±1.2%, respectively. For the two-step culture, the cleavage rate did not differ from that of the one-step culture system, ranging from 64.8 to 76.5%. Also, no effects of the two-step systems were observed on total cell number (63.0-78.8) or the proportion of apoptotic nuclei (3.3-5.3%) at the blastocyst stage. The culture of CEO in group 1 (without the supplements) had a reduced blastocyst rate (17.4±0.4%; P&lt;0.05) compared with the standard one-step maturation group, and the addition of P4 (but not PRL) improved the blastocyst yield (P&lt;0.05). Furthermore, when P4 (but not PRL) was added to group 2 and group 3 media, blastocyst rates increased significantly (32.9±3.1 and 32.8±2.7%, respectively) compared with those of the one-step group (P&lt;0.05), but did not differ from those of untreated groups 2 and 3 (26.2±2.7 and 30.0±3.0%, respectively). Our data indicate that P4 supplementation during the terminal phase of two-step IVM can enhance the developmental competence of bovine oocytes and that the nature of this effect depends on the composition of IVM medium, whereas no effect of PRL supplementation was observed. The study was supported by RFBR (No. 17-29-08035).

scholarly journals High revivability of vitrified–warmed bovine mature oocytes after recovery culture with α-tocopherol

Reproduction ◽  
2015 ◽  
Vol 149 (4) ◽  
pp. 347-355 ◽  
Author(s):  
Ikuko Yashiro ◽  
Miho Tagiri ◽  
Hayato Ogawa ◽  
Kazuya Tashima ◽  
Seiji Takashima ◽  
...  
Keyword(s):  
Cell Number ◽  
Total Cell ◽  
Developmental Competence ◽  
Control Group ◽  
Mitochondrial Activity ◽  
Cortical Granules ◽  
Total Cell Number ◽  
Recovery Culture ◽  
Bovine Oocytes

The objective of this study was to investigate whether developmental competence of vitrified–warmed bovine oocytes can be improved by antioxidant treatment during recovery culture. In experiment 1, one of the two antioxidants (either l-ascorbic acid or α-tocopherol) was added as a supplement to the recovery culture medium to which postwarming oocytes were exposed for 2 h before IVF. The exposure to α-tocopherol had a positive effect on rescuing the oocytes as assessed by the blastocyst yield 8 days after the IVF (35.1–36.3% vs 19.2–25.8% in untreated postwarming oocytes). Quality of expanding blastocysts harvested on Day 8 was comparable between α-tocopherol-treated vitrification group and fresh control group in terms of total cell number and chromosomal ploidy. In experiment 2, level of reactive oxygen species, mitochondrial activity, and distribution of cortical granules in α-tocopherol-treated postwarming oocytes were assessed. No obvious differences from the control data were found in these parameters. However, the treatment with α-tocopherol increased the percentage of zygotes exhibiting normal single aster formation (90.3% vs 48.0% in untreated postwarming oocytes; 10 h post-IVF). It was concluded that α-tocopherol treatment of vitrified–warmed bovine mature oocytes during recovery culture can improve their revivability, as shown by the high blastocyst yield and the higher mean total cell number in the blastocysts.

235 A COMPARISON OF PARTHENOGENETIC DEVELOPMENT OF PORCINE OOCYTES SYNCHRONISED DURING MATURATION BY CYCLOHEXIMIDE OR cAMP

2009 ◽  
Vol 21 (1) ◽  
pp. 215
Author(s):  
W. C. Chen ◽  
J. Zhu ◽  
P. Fisher ◽  
D. Amarnath ◽  
K. H. S. Campbell
Keyword(s):  
Time Window ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Total Cell ◽  
Blastocyst Formation ◽  
Cleavage Rate ◽  
Chi Square ◽  
Parthenogenetic Development ◽  
High Level

In vitro maturation of porcine oocytes is characterized by a high level of asynchrony between oocytes. Previous studies reported that cycloheximide (CHX) and 3′, 5′-cyclic AMP (cAMP) synchronize porcine oocytes and improve development to blastocyst stage following IVF or have been used for somatic cell nuclear transfer (SCNT) (Ye et al. 2005 Biol. Reprod. 72(2), 399–406; Betthauser et al. 2000 Nat. Biotechnol. 18(10), 1055–1059). We previously reported that cAMP was more effective than CHX in synchronizing porcine oocyte maturation, producing MII oocytes in a shorter time window and providing a more homogenous population for future SCNT studies (Chen et al. 2008 SRF conference, 2008 abst, p34). Here we compared parthenogenetic development of porcine oocytes synchronized by these two treatments. Selected cumulus–oocyte complexes (COC) obtained from slaughtered gilts were randomly divided into three groups and cultured at 39°C, 5% CO2 in air in modified NCSU-23 medium (with 1 μm glutathione, 1 mm cysteine, 5 mg L–1 insulin, 10 ng mL–1 epidermal growth factor, 10% (v/v) porcine follicular fluid, 1% essential and 0.5% nonessential amino acids) ± hormones (10 IU mL–1 PMSG and 10 IU mL–1 hCG): (1) with hormones for the first 22 h and then without hormones until 44 h; (2) with hormones and 5 μg mL–1 CHX for 12 h, and then with hormones but no CHX until 44 h; (3) with hormones and 1 mm cAMP for 22 h, and then without hormones and cAMP until 44 h. Parthenogenetic development of cycloheximide and cAMP treated oocytes was compared by cleavage rate at 48 h postactivation (hpa) and blastocyst formation at 168 hpa. No significant differences were observed in the frequency of cleavage (96.7 ± 2.1% v. 81.4 ± 11.6% v. 84.5 ± 5.7%), development to blastocyst (28.3 ± 11.4% v. 27.1 ± 5.7% v. 32.8 ± 5.3%) between control, CHX or cAMP treated oocytes, respectively (chi-square test, P > 0.05). However, total cell number was significantly higher in the CHX group than cAMP group (42.7 ± 4.1 v. 31.8 ± 2.0, respectively; t-test, P < 0.05). The results demonstrate that synchronization of porcine oocytes by treatment with CHX or cAMP does not affect subsequent parthenogenetic development if judged by the blastocyst formation, although the meaning of the difference of total cell numbers between CHX and cAMP treatments is still unclear.

140 EFFECT OF A NOVEL BOVINE EMBRYO CULTURE MEDIUM TO IMPROVE BLASTOCYST DEVELOPMENT

2013 ◽  
Vol 25 (1) ◽  
pp. 217
Author(s):  
R. F. Gonçalves ◽  
C. Figueiredo ◽  
M. A. Achilles
Keyword(s):  
Culture Medium ◽  
Apoptotic Cell ◽  
Cell Number ◽  
Total Cell ◽  
Cell Numbers ◽  
Group 2 ◽  
Group 1 ◽  
Hatching Rates

There are still immense differences in the quality of in vitro-produced embryos compared to their in vivo-generated counterparts. These differences include a higher sensitivity of in vitro-produced embryos towards cryopreservation. The quality of such embryos has been evaluated using various parameters like morphological examination, assessment of total cell numbers, or pregnancy rates after transfer. In the present study, the effects of glycine, alanine, taurine, and glutamine addition to SOF (Achilles Genetics culture medium, Achilles Genetics®, Garça, SP, Brazil) on the in vitro development (cleavage and blastocyst rates) and quality (total cell and apoptotic cell numbers) of bovine embryos were determined. Ovaries of Nelore cows were obtained from a slaughterhouse. Cumulus–oocyte complexes (COC) were collected from follicles ≥4 mm in diameter, matured in TCM-199, and fertilized with frozen–thawed Nelore bull semen (IVF = Day 0). On Day 1, presumptive zygotes were cultured in SOF supplemented with fetal bovine serum (FBS, group 1, n = 550) or in Achilles Genetics culture medium (SOF supplemented with Achilles Mixture and FBS, group 2, n = 557) at 38.5°C and 5% CO2 in air until Day 9. Embryos were evaluated during culture: at Day 3 cleavage rates, at Day 7 blastocyst rates, and on Day 9 hatching rates. Experiments were replicated 5 times, analysed using ANOVA, followed by a comparison of means by Tukey test (P ≤ 0.05). Blastocysts at Day 8 from Group 1 (n = 75) and Group 2 (n = 75) were fixed and permeabilized for TUNEL assay (DeadEndTM Florimetric TUNEL System, Promega, Madison, WI, USA), according to the manufacturer instructions. Total cell number, apoptotic cell number, and apoptotic cell index (calculated by dividing the apoptotic cell number by total cell number) were analyzed by analysis of variance and means were compared by Student Newman Keuls test. The threshold of significance was set at P ≤ 0.05. Cleavage rates were 79.2 ± 2.5 for group 1 and 91.0 ± 2.5 for group 2. Blastocyst and hatching rates (calculated on the total of zygotes) for group 2 (47.4 ± 2.8; 82.1 ± 1.5) were significantly greater than for group 1 (39.8 ± 2.8; 74.3 ± 1.5). The total cell numbers were not different (P > 0.05) between group 1 (112.7 ± 2.9) and group 2 (111.1 ± 2.7). Blastocysts from group 2 showed lower (P < 0.05) number of apoptotic cells (10.7 ± 1.2) than those from group 1 (20.9 ± 1.2). These results indicate that the addition of glycine, alanine, taurine, and glutamine to SOF (Achilles Mixture) may be an important energy source for the bovine blastocyst and could act synergistically to enhance embryo development to the hatching stage and embryo quality. Financial support from CNPq and FAPESP.

147 THE DEVELOPMENTAL CHARACTERISTICS OF IN VITRO-PRODUCED CATTLE-WISENT (BOS TAURUS-BISON BONASUS) HYBRID EMBRYOS

2017 ◽  
Vol 29 (1) ◽  
pp. 182
Author(s):  
E. N. Shedova ◽  
G. N. Singina ◽  
V. A. Bagirov ◽  
N. A. Zinovieva
Keyword(s):  
Bos Taurus ◽  
Apoptotic Cell ◽  
Cell Number ◽  
Total Cell ◽  
European Bison ◽  
Bison Bonasus ◽  
Epididymal Sperm ◽  
Total Cell Number ◽  
Cell Ratio

Interspecies hybrids are important resources for research and agriculture. Therefore, the aim of this study was to evaluate development, quality, and viability of embryos produced in vitro using cattle (Bos taurus) oocytes and European bison (Bison bonasus) epididymal sperm. The epididymes were obtained following a forced slaughter of one bull aged 7 years. The sperm was collected by scraping the inner surface of the epididymes, diluted with the cryopreservation medium, and equilibrated for 4 h at 4°C. Thereafter, sperm aliquots (0.2 mL) were frozen in liquid nitrogen vapor for 5 min and then plunged into liquid nitrogen for storage. Prior to fertilization, frozen semen was thawed in pre-warmed medium for 1 min at 37°C and prepared by the swim-up method. The frozen-thawed ejaculated sperm from the Russian Black Pied bulls was used as a positive control. Slaughterhouse-derived cumulus-oocyte complexes were matured for 24 h in TCM-199 supplemented with 10% FCS, 0.2 mM sodium pyruvate, 10 μg mL−1 porcine FSH, and 10 μg mL−1 ovine LH. Matured oocytes (35–40 oocytes per group) were co-incubated for 18 h with homologous (n = 266 oocytes) or heterologous (n = 292 oocytes) sperm (spermatozoa/mL) in 500 µL of TALP containing 10 μg mL−1 heparin, 20 μM penicillamine, 10 μM hypotaurine, 1 μM epinephrine, and 0.1% minimal essential medium nonessential amino acids. After IVF, the oocytes were cultured in CR1aa medium (Rosenkrans 1994 J. Anim. Sci. 72, 434–437) to the blastocyst stage. All the cultures were performed at 38.5°C and 5% CO2 in humidified air. At Days 2 and 7 after insemination, the cleavage and blastocyst rates were determined. In addition, a part of obtained blastocysts was fixed with 4% paraformaldehyde, and the total cell number and apoptotic cell ratio were determined by 4’,6-diamidino-2-phenylindole and TUNEL staining. The remaining blastocysts were cultured up to Day 10, and the hatching rates were assessed. The data (3–5 replicates) were analysed by ANOVA. The cleavage rates did not differ among both male species (72.4 and 77.1%). Furthermore, no significant effects of interspecies fertilization on the blastocyst rate or total cell number per blastocyst were found (27.4 ± 1.6% and 77.0 ± 5.7 for cattle embryos and 26.2 ± 1.9% and 83.1 ± 8.9 for cattle-wisent hybrid embryos). On the other hand, the significant differences between homologous and heterologous fertilization were detected in the rate of hatched blastocysts (60.3 ± 5.1 v. 38 ± 2.9, P < 0.05) and apoptotic cell ratio 7.3 ± 0.8 v. 11.6 ± 1.04, P < 0.05). Our findings demonstrate that hybrid embryos produced by IVF of bovine oocytes with the epididymal sperm of European bison can be developed up to advanced blastocyst stages. However, the hybrid embryos have a lower quality and viability than cattle embryos. Research was supported by the Program of Presidium of the Russian Academy of Science, project no. IV.13.3.

83 IN LOW OXYGEN CULTURE, IS HYPOTAURINE NECESSARY FOR IN VITRO DEVELOPMENT OF PORCINE EMBRYOS?

2016 ◽  
Vol 28 (2) ◽  
pp. 171
Author(s):  
J. A. Benne ◽  
L. D. Spate ◽  
B. M. Elliott ◽  
R. S. Prather
Keyword(s):  
Embryo Culture ◽  
Cell Number ◽  
Blastocyst Stage ◽  
Total Cell ◽  
Free Radical Scavengers ◽  
Total Cell Number ◽  
In Vitro Development ◽  
Significant Difference ◽  
Vitro Development

For decades it has been known that reactive oxidative species (ROS) form during in vitro embryo culture. A buildup of ROS can be detrimental to individual cells in the embryo and lead to a decrease in development and quality. To overcome oxidative stress in culture systems, additives, such as taurine and/or hypotaurine, have been used. In the pig, taurine or hypotaurine addition is deemed necessary for normal in vitro development. Another commonly used technique to reduce ROS is to culture embryos in a lowered oxygen environment (e.g. 5%). Porcine zygote medium 3 (PZM3) base culture medium is used in the following experiments and contains 5 mM hypotaurine, which is one of the most costly additives in the medium. The objective of this experiment was to determine if hypotaurine is still necessary if the embryos were cultured in 5% O2 from the zygote to the Day 6 blastocyst stage. In Experiment 1, oocytes were matured for 44 h and fertilized in vitro. After fertilization, presumptive zygotes were then transferred to 500 µL of MU-1 medium (PZM3 with 1.69 mM arginine) that either contained or did not contain hypotaurine for overnight culture at 20% O2. On Day 1, the same embryo culture plates were moved to 5% O2, 5% CO2, and 90% N2 and cultured to Day 6. The percent blastocyst stage was determined, and total cell number was counted in 3 of the 5 replicates in order to give us an indication of the embryo quality. The percent blastocyst in the controls (+hypotaurine) was 34.4% ± 2.8 and not different from the no hypotaurine (32.9% ± 2.2; N = 830; 5 replications; P > 0.10). Furthermore, total cell number was not different between the two groups (30.8 ± 1.5 v. 33.6 ± 1.8, respectively, N = 146; 3 replications; P > 0.10). In Experiment 2, the same experiment was repeated in somatic cell nuclear transfer derived embryos, which may be more sensitive to ROS due to the micromanipulation procedure. Wild type fetal fibroblast cells were used as donor cells. There was no significant difference in development to the blastocyst stage due to the presence or absence of hypotaurine (17.7% ± 2.5 v. 11.8% ± 2.3, respectively; N = 454; 4 replications; P = 0.07). All blastocyst data were analysed using the GENMOD procedure in SAS 9.4 (SAS Institute Inc., Cary, NC, USA), and cell number data were analysed using the PROC GLM also with SAS 9.4. These data show that porcine embryos can be efficiently cultured to the blastocyst stage without adding any oxygen free radical scavengers to the media when culturing in reduced oxygen atmosphere. Further studies include evaluating term development via embryo transfers and measuring ROS production of these embryos. Funding was provided by Food for the 21st Century and the National Institutes of Health (U42 OD011140).

Sperm-borne small RNAs improve the developmental competence of pre-implantation cloned embryos in rabbit

Zygote ◽  
2021 ◽  
pp. 1-6
Author(s):  
Hongyu Qin ◽  
Pengxiang Qu ◽  
Huizhong Hu ◽  
Wenbin Cao ◽  
Hengchao Liu ◽  
...  
Keyword(s):  
Small Rnas ◽  
Apoptotic Cell ◽  
Epigenetic Modification ◽  
Cell Number ◽  
Total Cell ◽  
Developmental Competence ◽  
Control Group ◽  
Total Cell Number ◽  
Cell Stage ◽  
Micro Rnas

Summary The low efficiency of somatic cell nuclear transfer (SCNT) greatly limits its application. Compared with the fertilized embryo, cloned embryos display abnormal epigenetic modification and other inferior developmental properties. In this study, small RNAs were isolated, and miR-34c and miR-125b were quantified by real-time PCR; results showed that these micro-RNAs were highly expressed in sperm. The test sample was divided into three groups: one was the fertilized group, one was the SCNT control group (NT-C group), and the third group consisted of SCNT embryos injected with sperm-borne small RNA (NT-T group). The level of tri-methylation of lysine 9 on histone H3 (H3K9me3) at the 8-cell stage was determined by immunofluorescence staining, and the cleavage ratio, blastocyst ratio, apoptotic cell index of the blastocyst and total cell number of blastocysts in each group were analyzed. Results showed that the H3K9me3 level was significantly higher in the NT-C group than in the fertilized group and the NT-T group. The apoptosis index of blastocysts in the NT-C group was significantly higher than that in the fertilized group and the NT-T group. The total cell number of SCNT embryos was significantly lower than that of fertilized embryos, and injecting sperm-borne small RNAs could significantly increase the total cell number of SCNT blastocysts. Our study not only demonstrates that sperm-borne small RNAs have an important role in embryo development, but also provides a new strategy for improving the efficiency of SCNT in rabbit.

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