79RELATIONSHIPS BETWEEN SURVIVAL RATE AND BIRTH WEIGHT IN CLONED KOREAN NATIVE CALVES

2004 ◽  
Vol 16 (2) ◽  
pp. 161
Author(s):  
B.C. Yang ◽  
G.S. Im ◽  
D.H. Kim ◽  
S.K. Lee ◽  
H.S. Park ◽  
...  
Keyword(s):  
Birth Weight ◽  
Survival Rate ◽  
Caesarean Section ◽  
Survival Rates ◽  
Blastocyst Stage ◽  
High Birth Weight ◽  
Gestation Length ◽  
Average Birth Weight ◽  
Fetal Bovine

Cloning of somatic cells has been investigated actively in cattle, but the cloned calves have been characterized by high birth weight and low survival rate. The present study was conducted to investigate the relationships between survival rate and birth weight in cloned and AI calves. The ear skin fibroblasts were obtained from 2- to 3-year-old Korean native cows (Hanwoo) and the cells were cultured in Dulbeccos Modified Eagles medium (DMEM) supplemented with 10% fetal bovine serum (FBS) at 38.5°C, 5% CO2 in air. Bovine oocytes collected from ovaries obtained from a nearby slaughterhouse were cultured in vitro and then enucleated, injected with donor cells and fused, and cultured to produce cloned embryos at the blastocyst stage. Somatic cell cloning and in vitro culture of embryos were performed by the procedures described previously (Im et al., 2001 AJAS 14, 759–764, and Im et al., 2001 AJAS 14, 1260–1266). A total of 580 cloned embryos at blastocyst stage were transferred to 293 recipient cows; 32 female calves (5.5%) were born (2 of them were born dead). Thirty-four (15 female and 19 male ) calves (57.6%) were born from 59 artificially inseminated Korean native cows as control. Fifteen of the 32 cloned calves were delivered by caesarean section. However, all the artificially inseminated cows delivered naturally. Birth weights of 30 live cloned calves averaged 31.08kg (>15kg:3, 20kg:2, 25kg:2, 30kg:5, 35kg:9, 40kg:6, <45kg:3), while those of female AI calves averaged 23.67kg (>15kg:0, 20kg:3, 25kg:6, 30kg:6, 35kg:0, 40kg:0, <45kg:0). After calving, 11 of 30 cloned calves survived for more than 365 days (birth weight of these calves averaged 28.25kg), but 19 of 30 calves died within 175 days and their average birth weight was 32.80kg (650kg). Gestation length of cows that received cloned embryos was 287 (279–295) days on average (excluding the data of calves delivered by caesarean section) and that of cows artificially inseminated was 287 (255–293) days. In conclusion, the birth weight was significantly correlated (P<0.05) with survival rate of cloned calves, and survival rates of calves with extremely high or low birth weights were significantly low. However, there was no relationship between gestation length and survival rate.

212 INSEMINATION OF OVUM PICKUP-DERIVED DAIRY COWS RESULTS IN OFFSPRING WITH NORMAL BIRTH WEIGHT

2008 ◽  
Vol 20 (1) ◽  
pp. 185
Author(s):  
E. Mullaart ◽  
B. Landman ◽  
J. S. Merton
Keyword(s):  
Birth Weight ◽  
First Generation ◽  
Second Generation ◽  
Calf Serum ◽  
Control Group ◽  
High Birth Weight ◽  
Gestation Length ◽  
Aberrant Methylation ◽  
Epigenetic Changes

Animals derived by ovum pickup-in vitro production (OPU-IVP) have a higher birth weight compared with animals derived by AI (Wagtendonk et al. 2000 Theriogenology 53, 575–597). It has been suggested that this higher birth weight is the result of epigenetic changes such as aberrant methylation and gene expression pattern, which are caused by the presence of serum in the culture medium (Wrenzycki et al. 2004 Anim. Reprod. Sci. 82–83, 593–603). The present study aimed to investigate whether the higher birth weight, possibly caused by epigenetic changes, is a permanent characteristic that is transmitted to the offspring. We therefore monitored the birth weight of calves born after insemination of OPU-IVP-derived animals. Ovum pickup-IVP was performed according to routine procedures. Immature COC were recovered by OPU. The COC were matured in vitro in TCM-199 supplemented with fetal calf serum (FCS)/LH/FSH. Subsequently, matured oocytes were fertilized with frozen–thawed gradient-separated semen and further cultured for 7 days in TCM-199/10% FCS on a BRL monolayer (CoCul group) or in SOFaaBSA (SOF group). First-generation OPU-IVP animals were produced from oocytes collected by OPU of AI-derived animals. The second generation was produced by inseminating OPU-IVP animals. Calves generated by inseminating AI animals were used as a control group. Birth weights of control AI, first-generation, and second-generation calves were analyzed by using restricted maximum likelihood (Genstat 9.1). Model Birth Weight: *Fixed: Parity Recipient + Sex + Gestation Length + Year + Embryo Type (AI, first, or second generation) + Culture System (CoCul or SOF). *Random: Sire + Barn. The results (Table 1) clearly show that the first-generation (OPU-IVP) calves had, on average, a 3.4-kg greater birth weight than the AI calves. The second-generation calves, however, had approximately the same birth weight as the calves in the AI control group. Our results indicated that the high birth weight of OPU-IVP-derived calves is not a permanent characteristic that is transmitted to their offspring. Previous studies have demonstrated that the fertility of OPU-IVP-derived animals is in the normal range (Wagtendonk et al. 2000 Theriogenology 53, 575–597). Table 1. Birth weight (least squares means ± SE) of AI calves (control), first generation OPU-IVP-derived calves, and second generation AI derived calves from OPU-IVP mothers

Different in vitro culture systems affect the birth weight of lambs from vitrified ovine embryos

Zygote ◽  
2013 ◽  
Vol 23 (1) ◽  
pp. 53-57 ◽  
Author(s):  
L. Mara ◽  
D. Sanna ◽  
M. Dattena ◽  
I.M. Mayorga Muñoz
Keyword(s):  
Fatty Acid ◽  
Birth Weight ◽  
Bovine Serum ◽  
Blastocyst Stage ◽  
Test Body ◽  
Culture Systems ◽  
Significant Difference ◽  
Fetal Bovine ◽  
Lambing Rate

SummaryIt has been reported that different in vitro culture systems affect the birth weight of lambs. The aim of this study was to test body weight and lambing rate of lambs born from five different in vitro culture systems after vitrification. Oocytes of Sarda sheep were matured in TCM-199 plus 0.4% bovine serum albumin (BSA) using systems: (i) 4 mg/ml fatty acid-free BSA (BSA4); (ii) 8 mg/ml fatty acid-free BSA (BSA8); (iii) BSA8–hyaluronan (BSA8–HA); (iv) BSA8–charcoal-stripped FBS (BSA8–CH); or (v) with 10% fetal bovine serum (FBS; serum) and fertilized with fresh semen. The presumptive zygotes were cultured up to the blastocyst stage with BSA8, BSA8-HA, BSA8-CH or serum or BSA4. In the third and fifth days of culture 5% charcoal-stripped FBS was added into BSA8-CH and serum, while 8 mg/ml or 4 mg/ml fatty acid-free BSA was added as BSA8, BSA8-HA and BSA4 respectively; 6 mg/ml HA was added to BSA8-HA. In total, 240 vitrified blastocysts were transferred into synchronized ewes. The lambing rate was not significant different between BSA groups or between serum groups (BSA8-CH and serum), while serum groups showed significant lower values when compared with BSA groups. Only BSA8 groups produced heavy lambs (≥4.5 kg) with a significant difference between BSA4 and BSA8 groups (P < 0.05).

scholarly journals High in vitro survival rate of sheep in vitro produced blastocysts vitrified with a new method and device

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Sergio Ledda ◽  
Jen M. Kelly ◽  
Stefano Nieddu ◽  
Daniela Bebbere ◽  
Federica Ariu ◽  
...  
Keyword(s):  
Survival Rate ◽  
Survival Rates ◽  
Blastocyst Stage ◽  
Hatching Rate ◽  
High Survival ◽  
Apoptotic Cells ◽  
Embryo Survival ◽  
New Device ◽  
In Vitro Survival

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.

scholarly journals Obstetric Anal Sphincter Injuries – Maternal, Foetal and Sociodemographic Risk Factors: A Retrospective Register-Based Study

2021 ◽  
Author(s):  
Kristin André ◽  
Andrea Stuart ◽  
Kärin Kallén
Keyword(s):  
Risk Factors ◽  
Birth Weight ◽  
Caesarean Section ◽  
Anal Sphincter ◽  
Maternal Education ◽  
Vacuum Extraction ◽  
High Birth Weight ◽  
Previous Caesarean Section ◽  
Obstetric Anal Sphincter Injuries ◽  
Increased Risk

Objective. To determine risk and protective factors of obstetric anal sphincter injuries (OASIS). Design. A retrospective register-based observational study. Setting. Sweden. Population. A cohort of 988, 988 singleton term deliveries 2005-2016 were included. Methods. Data from the Swedish Medical Birth Registry and Statistics Sweden were extracted to identify cases of OASIS and maternal and foetal characteristics. Modified Poisson Regression analyses were performed to assess risk factors. Main outcome measures. Risk ratios for OASIS with 95% confidence interval associated with maternal and foetal risk factors were calculated. Results. The rate of OASIS was 3.5% (n=34, 583). Primiparity (aRR 3.13 95% CI 3.05–3.21), vacuum extraction (aRR 2.79 95% CI 2.73–2.86), forceps (aRR 4.27 95% CI 3.86–4.72) and high birth weight (aRR 2.61 95% CI 2.50–2.72) were associated with a significantly increased risk of OASIS. Increasing maternal age and decreasing maternal height increased the risk of OASIS. Smoking (aRR 0.74 95% CI 0.70–0.79) and low maternal education (aRR 0.87 95% CI 0.83–0.92) were associated with a decreased frequency of reported OASIS. Obesity decreased the risk of OASIS (aRR 0.90 95% CI 0.87–0.94), but only after adjusting for foetal birth weight. Previous caesarean section increased the risk of OASIS (aRR 1.41; 95% CI 1.36–1.47). Conclusion. Primiparity, instrumental delivery and high birth weight increased the risk of OASIS. Risk factors including BMI, height, age, smoking, maternal education, ethnicity and previous caesarean section also contribute to the overall risk of OASIS. Keywords. Obstetric sphincter injuries, risk factors, pregnancy.

83 VITRIFICATION OF IMMATURE AND IN VITRO-MATURED HORSE OOCYTES

2006 ◽  
Vol 18 (2) ◽  
pp. 149 ◽  
Author(s):  
L. Bogliolo ◽  
F. Ariu ◽  
I. Rosati ◽  
M. T. Zedda ◽  
S. Pau ◽  
...  
Keyword(s):  
Survival Rate ◽  
Ethylene Glycol ◽  
Survival Rates ◽  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Hoechst 33342 ◽  
Nuclear Maturation ◽  
And Control ◽  
Cryopreservation Protocol

Few attempts have been carried out to cryopreserve equine oocytes, and an effective cryopreservation protocol is not defined yet. Studies were conducted to compare the viability of immature and in vitro-matured horse oocytes vitrified by the minimal volume cooling (MVC) cryotop vitrification method (Kuwayama et al. 2005 Reprod. BioMed. Online 11, 300–308). Oocytes were recovered from slaughterhouse ovaries and divided, on the basis of the morphology of cumulus cells, into cumulus-expanded (CE) and cumulus-compacted (CC) oocytes. Groups of CC and CE oocytes were vitrified immediately after recovery [germinal vesicle (GV) stage] or matured in vitro (IVM) and cryopreserved at the MII stage as follows: oocytes were incubated 30 min in TCM-199 + 20% FCS + 10% ethylene glycol (EG) + 10% DMSO, followed by 20 min in TCM-199 + 20% FCS + 20% EG + 20% DMSO + 0.25 M sucrose, loaded in cryotops (2 µL), and plunged into liquid nitrogen. Warming was performed at 38.5°C by washing the oocytes in TCM-199 + 20% FCS with decreasing sucrose concentrations (1.25 M, 0.62 M, 0.31 M). After warming oocytes cryopreserved at the GV stage were matured in vitro for 24 h (CE) or 36 h (CC) in TCM-199 + 10% FCS + FSH, LH each at (0.1 UI/mL) + cysteamine, fixed, and stained with glycerol-Hoechst 33342 to assess nuclear maturation. Oocytes vitrified at the MII stage were in vitro cultured for 2 h to evaluate their morphological survival on the basis of the presence of an intact zona pellucida and membrane. Nonvitrified oocytes undergoing the same maturation protocol were used as controls. Results (Table 1) indicated that the survival rate of oocytes vitrified at the GV stage, after IVM, was similar between CE and CC oocytes (43.6% vs 42.6%). Significantly (P < 0.01) higher numbers of vitrified CE MII oocytes (52.9%) survived, compared to CC (34.8%), after 2-h culture. The percentages of viable MII oocytes from CE and CC GV vitrified oocytes were 43.6% and 40.9% respectively and were comparable to those from vitrified MII oocytes (CE, 52.9%; CC, 34.8%) and control oocytes (CE, 56.4%; CC, 53.3%). In conclusion, the results of this study showed that vitrification by the MCV Cryotop method of horse oocytes at either the GV or the MII stage allows a similar number of viable mature oocytes to be recovered. Table 1. Maturation and survival rates of immature and mature equine oocytes vitrified by the MCV Cryotop method

86 BIRTH OF HEALTHY CALVES AFTER INTRAFOLLICULAR OOCYTE TRANSFER

2015 ◽  
Vol 27 (1) ◽  
pp. 136
Author(s):  
M. Hoelker ◽  
A. Kassens ◽  
E. Held ◽  
C. Wrenzycki ◽  
U. Besenfelder ◽  
...  
Keyword(s):  
Lipid Content ◽  
Ex Vivo ◽  
Survival Rates ◽  
Blastocyst Stage ◽  
Culture Conditions ◽  
In Vitro Production ◽  
Negative Effects ◽  
Uterine Flushing

The in vitro production (IVP) of bovine embryos is a well-established technique that has been available for nearly 20 years. However, there remain major differences between IVP-derived blastocysts and their in vivo-derived counterparts. Many studies have pointed out that most of these differences are due to the in vitro developmental environment. To circumvent these negative effects due to in vitro culture conditions, a new method – intrafollicular oocyte transfer (IFOT) – was established in the present study. Using modified ovum pick-up (OPU) equipment, in vitro-matured oocytes derived from slaughterhouse ovaries were injected into the dominant preovulatory follicle of synchronised heifers (follicular recipients) enabling subsequent ovulation, in vivo fertilization, and in vivo development. A total of 810 in vitro-matured oocytes were transferred into 14 heifers. Subsequently, 222 embryos (27.3%) were recovered after uterine flushing at Day 7. Based on the number of cleaved embryonic stages, 64.2% developed to the blastocyst stage, which did not differ from the IVP-derived embryos (58.2%). Interestingly, lipid content of IFOT-derived blastocysts did not differ from the fully in vivo-produced embryos, whereas IVP-derived blastocysts showed significantly higher lipid droplet accumulation compared with fully in vivo-derived and IFOT-derived blastocysts (P < 0.05). Accordingly, IFOT blastocysts showed significantly higher survival rates after cryopreservation than complete IVP-derived embryos (77% v. 10%), which might be attributed to a lower degree of lipid accumulation. In agreement, transfer of frozen-thawed IFOT blastocysts to synchronized recipients (uterine recipients) resulted in much higher pregnancy rates compared with transfer of IVP-derived blastocysts (42.1 v. 13.8%) but did not differ from frozen-thawed ex vivo blastocysts (52.4%). Of these presumed IFOT pregnancies, 7 went to term, and microsatellite analysis confirmed that 5 calves were indeed derived from IFOT, whereas 2 were caused by fertilization of the follicular recipient's own oocyte after AI. Taken together, IFOT-derived blastocysts closely resemble in vivo-derived blastocysts, confirming earlier suggestions that the ability to develop to the blastocyst stage is already determined in the matured oocyte, whereas the quality in terms of lipid content and survival rate after cryopreservation is affected by the environment thereafter. However, to the best of our knowledge, this is the first study reporting healthy calves after intrafollicular transfer of in vitro-matured oocytes.

47 A New Device and Method for Successful Vitrification of In Vitro-Produced Ovine Embryos

2018 ◽  
Vol 30 (1) ◽  
pp. 163
Author(s):  
S. Ledda ◽  
J. M. Kelly ◽  
S. K. Walker ◽  
Y. Natan ◽  
A. Arav
Keyword(s):  
Survival Rate ◽  
Embryo Transfer ◽  
Blastocyst Stage ◽  
Embryo Cryopreservation ◽  
Control Group ◽  
Hatching Rate ◽  
High Survival ◽  
Embryo Survival ◽  
New Device

To advance the use of embryo vitrification technology in veterinary practice, we developed a system in which embryo vitrification, warming, and dilution can be performed within a straw. An in-straw embryo cryopreservation method reduces the need for equipment and technical skills and can facilitate direct embryo transfer to the uterus. This study proposes the use of a new device named “Sarah” that is designed to permit all in-straw embryo cryopreservation procedures. Ovine in vitro-produced (IVP) embryos were vitrified at either early blastocyst stage (EB, n = 65, 6 days post-IVF) or fully expanded blastocyst stage (FB, n = 168, 7 days post-IVF). The vitrification procedure using Sarah constituted a 0.25-mL straw with a capsule having 50-µm pores inserted at one end. Embryos at each stage (EB and FB) were divided into 2 subgroups and vitrified by 1 of 2 methods: (1) multi-step (MS) group-a straw containing 2 embryos was sequentially loaded vertically into 1.5-mL tubes containing 6 different vitrification solutions: 10, 20, 40, 60, 80, or 100% ES (with 100% ES being 7.5% DMSO +7.5% EG + 20% FCS in TCM-199; 90 s each step) followed by 30 s each in 75 and 100% VS (100% VS being 18% DMSO +18% EG + 0.5 M trehalose + BSA in TCM-199); and (2) two-step (TS) group-the straw (2 embryos/straw) was loaded with 100% of ES (5 min), followed by 100% VS solution for 30 s. For both methods, at the end of the preparation steps, the straws were plunged directly into liquid N2. Non-vitrified embryos were maintained in in vitro culture as a control group (n = 102). The warming procedure consisted of placing the straws directly into 5-mL tubes containing 100, 50, 25% WS (WS = 1 M sucrose in TCM-199+ 20% FCS) at 38.6°C (for first solution) and at room temperature for all the rest (5 min each), before being placed into the holding medium. Embryos were recovered from the straws, incubated at 38.6 C in 5% CO2 in air in TCM 199 + 5% FCS, and evaluated for blastocoel re-expansion, embryo survival, and hatching rate at 2, 14, 48 h post-warming. Blastocyst re-expansion (2 h) after warming increased as the developmental stage progressed and was not affected by the vitrification method. In fact, it was significantly (P < 0.05) higher for FB vitrified in the MS and TS methods (77.90% and 71.25%, respectively) compared with the EB method (62.5% and 48.50%, respectively). At 24 h, survival rate of vitrified FB was significantly higher (P < 0.05) in the MS system (95.35%) compared with those in TS (86.25%). Survival rates of FB embryos for both methods (MS and TS) were significantly higher (P < 0.001) than EB embryos vitrified in MS (56.25%) and TS (56.55) methods. After 48 h of culture, the hatching rate for FB vitrified in the MS system (87.21%) was comparable with TS (77.5%) and control (85.3%) groups but significantly higher (P < 0.001) than vitrified EB in MS (43.75%) and TS (36.36%). In conclusion, we showed that a high survival rate of IVP embryos can be achieved by this new in-straw vitrification and warming device (“Sarah”), with hatching rates in vitro comparable with that of control fresh embryos. This method has the potential for use in direct embryo transfer in field conditions.

34 EFFECTS OF L-CARNITINE AND trans-10,cis-12 CONJUGATED LINOLEIC ACID SUPPLEMENTATION DURING MATURATION ON DEVELOPMENT AND CRYOTOLERANCE OF BOVINE EMBRYOS PRODUCED IN VITRO

2016 ◽  
Vol 28 (2) ◽  
pp. 147
Author(s):  
J. Block ◽  
A. M. Zolini ◽  
E. Carrascal-Triana ◽  
A. Ruiz ◽  
P. J. Hansen ◽  
...  
Keyword(s):  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Embryo Development ◽  
Blastocyst Stage ◽  
Cleavage Rate ◽  
Sodium Pyruvate ◽  
Maturation Medium ◽  
Fetal Bovine ◽  
Hatching Rates

The objective of the present study was to determine the effect of supplementation of maturation media with L-carnitine and trans-10,cis-12 conjugated linoleic acid (CLA) on embryo development and survival following cryopreservation. Immature bovine cumulus-oocyte complexes (n = 1796) were harvested from abattoir-derived ovaries and randomly assigned in a 2 × 2 factorial design to be matured in maturation medium [TCM-199 with Earle salts supplemented with 10% (vol/vol) bovine steer serum, 2 μg mL–1 oestradiol 17-β, 20 μg mL–1 bovine FSH, 22 μg mL–1 sodium pyruvate, 50 μg mL–1 gentamicin sulfate, and 1 mM glutamax®] supplemented with or without 100 mM CLA and with or without 3.03 mM L-carnitine for 22 to 24 h at 38.5°C in a humidified atmosphere of 5% CO2. The proportion of oocytes that cleaved was determined on Day 3 after insemination, and the proportion of oocytes developing to the blastocyst and advanced blastocysts stages (expanded, hatching, and hatched) was assessed on Day 7. Blastocyst and expanded blastocyst stage embryos (n = 270) were harvested on Day 7 and subjected to controlled-rate freezing following equilibration in 1.5 M ethylene glycol. Embryos were thawed and then cultured for 72 h in SOF-BE1 (Fields et al. 2011) supplemented with 10% (vol/vol) fetal bovine serum and 50 μM dithiothreitol. Post-thaw re-expansion and hatching rates were determined at 24, 48, and 72 h. The experiment was replicated 5 times. There was no effect of supplementation of maturation medium with either CLA or L-carnitine on the proportion of oocytes that cleaved at Day 3 or that developed to the blastocyst and advanced blastocyst stages at Day 7 after insemination. There was no interaction between CLA and L-carnitine affecting cleavage rate or embryo development. Supplementation of maturation medium with L-carnitine did not affect post-thaw re-expansion or hatching rates. In contrast, treatment with CLA during maturation reduced (P < 0.05) post-thaw re-expansion (24 h: 75.2 ± 3.8% v. 60.3 ± 4.1%; 48 h: 82.0 ± 3.4% v. 64.9 ± 4.0%; 72 h: 78.9 ± 3.6% v. 65.9 ± 4.0%, respectively) and hatching (24 h: 33.7 ± 4.2% v. 23.5 ± 3.6%; 48 h: 61.1 ± 4.3% v. 44.0 ± 4.2%; 72 h: 62.6 ± 4.3% v. 50.2 ± 4.2%, respectively) rates at all time points. There was no interaction between CLA and L-carnitine affecting post-thaw viability. In conclusion, supplementation of maturation medium with L-carnitine did not affect embryo development or post-thaw viability. Although addition of CLA during maturation did not affect embryo development, post-thaw cryotolerance was reduced following CLA supplementation. There was no beneficial effect of supplementing maturation medium with both CLA and L-carnitine on embryo development or post-thaw cryosurvival.

80 Biallelic CRISPR-Cas9 editing of gene associated with coat colour in microinjected bovine zygotes reaching the blastocyst stage

2019 ◽  
Vol 31 (1) ◽  
pp. 165
Author(s):  
M. Poirier ◽  
D. Miskel ◽  
F. Rings ◽  
K. Schellander ◽  
M. Hoelker
Keyword(s):  
Gene Editing ◽  
Fluorescent Protein ◽  
Survival Rates ◽  
Coat Colour ◽  
Blastocyst Stage ◽  
Transcription Activator ◽  
Guide Rna ◽  
Blastocyst Rate ◽  
Copa Gene

Successful genome editing of blastocysts using zygote microinjection with transcription activator-like effector nucleases has already been accomplished in cattle as well as a limited number of CRISPR-Cas9 microinjections of zygotes, mostly using RNA. Recent editing of the Pou5f1 gene in bovine blastocysts using CRISPR-Cas9, clarifying its role in embryo development, supports the viability of this technology to produce genome edited cattle founders. To further this aim, we hypothesise that editing of the coatomer subunit α (COPA) gene, a protein carrier associated with the dominant red coat colour phenotype in Holstein cattle, is feasible through zygote microinjection. Here, we report successful gene editing of COPA in cattle zygotes reaching the blastocyst stage, a necessary step in creating genome edited founder animals. A single guide RNA was designed to target the sixth exon of COPA. Presumptive zygotes derived from slaughterhouse oocytes by in vitro maturation and fertilization were microinjected either with the PX458 plasmid (Addgene #48138; n=585, 25ng µL−1) or with a ribonucleoprotein effector complex (n=705, 20, 50, 100, and 200ng µL−1) targeting the sixth exon of COPA. Plasmid injected zygotes were selected for green fluorescent protein (GFP) fluorescence at Day 8, whereas protein injected zygotes were selected within 24h post-injection based on ATTO-550 fluorescence. To assess gene editing rates, single Day 8 blastocysts were PCR amplified and screened using the T7 endonuclease assay. Positive structures were Sanger sequenced using bacterial cloning. For plasmid injected groups, the Day 8 blastocyst rate averaged 30.3% (control 18.1%). The fluorescence rate at Day 8 was 6.3%, with a GFP positive blastocyst rate of 1.6%, totaling 7 blastocysts. The T7 assay revealed editing in GFP negative blastocysts and morulae as well, indicating that GFP is not a precise selection tool for successful editing. In protein injection groups, the highest concentration yielded the lowest survival rates (200ng µL−1, 50.0%, n=126), whereas the lowest concentration had the highest survival rate (20ng µL−1, 79.5%, n=314). The Day 8 blastocyst rate reached an average of 25% across groups. However, no edited blastocysts were observed in the higher concentration groups (100,200ng µL−1). The highest number of edited embryos was found in the lowest concentration injected (20ng µL−1, 4/56). Edited embryos showed multiple editing events neighbouring the guide RNA target site ranging from a 12-bp insertion to a 9-bp deletion, as well as unedited sequences. Additionally, one embryo showed a biallelic 15-bp deletion of COPA (10 clones). One possible reason for the presence of only mosaic editing and this in-frame deletion could be that a working copy of COPA is needed for proper blastocyst formation and that a knockout could be lethal. Additional validation and optimization is needed to elucidate the functional role of COPA during early development and its modulation when creating founder animals.

Embryo co-culture with bovine amniotic membrane stem cells can enhance the cryo-survival of IVF-derived bovine blastocysts comparable with co-culture with bovine oviduct epithelial cells

Zygote ◽  
2020 ◽  
pp. 1-6
Author(s):  
Shayan Nejat-Dehkordi ◽  
Ebrahim Ahmadi ◽  
Abolfazl Shirazi ◽  
Hassan Nazari ◽  
Naser Shams-Esfandabadi
Keyword(s):  
Stem Cells ◽  
Growth Factors ◽  
Epithelial Cells ◽  
Embryonic Development ◽  
Amniotic Membrane ◽  
Biological Activities ◽  
Survival Rates ◽  
Blastocyst Stage ◽  
Oviduct Epithelial Cells

Summary Culture conditions have a profound effect on the quality of in vitro-produced embryos. Co-culturing embryos with somatic cells has some beneficial effects on embryonic development. Considering the ability of stem cells to secrete a broad range of growth factors with different biological activities, we hypothesized that bovine amniotic membrane stem cells (bAMSCs) might be superior to bovine oviduct epithelial cells (BOECs) in supporting embryonic development and enhancing their cryo-survival. Bovine abattoir-derived oocytes were matured and fertilized in vitro. The resultant presumptive zygotes were then cultured up to the blastocyst stage in the following groups: (i) co-culture with bAMSCs, (ii) co-culture with BOECs, and (iii) cell-free culture (Con). Embryos that reached the blastocyst stage were vitrified and warmed, and their post-warming re-expansion, survival and hatching rates were evaluated after 72 h culture. Results showed that the cleavage, blastocyst, and 2 h post-warming re-expansion rates of embryos did not differ between groups. However, their survival rates in BOEC and bAMSC groups were significantly higher compared with the control (72.7, 75.6 and 37.5%, respectively, P < 0.05). In conclusion, our results showed that the cryo-survivability of IVF-derived bovine embryos could be improved through co-culturing with bAMSCs. Moreover, considering the possibility to provide multiple passages from bAMSCs compared with BOECs, due to their stemness properties and their ability to produce growth factors, the use of bAMSCs is a good alternative to BOECs in embryo co-culture systems.

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