Enhancement of porcine in vitro embryonic development through luteolin‑mediated activation of the Nrf2/Keap1 signaling pathway

Background Oxidative stress,caused by an imbalance in the production and elimination of intracellular reactive oxygen species(ROS),has been recognized for its detrimental effects on mammalian embryonic development.Luteolin(Lut)has been documented for its protective effects against oxidative stress in various studies.However,its specific role in embryonic development remains unexplored.This study aims to investigate the influence of Lut on porcine embryonic development and to elucidate the underlying mechanism.Results After undergoing parthenogenetic activation(PA)or in vitro fertilization,embryos supplemented with 0.5μmol/L Lut displayed a significant enhancement in cleavage and blastocyst formation rates,with an increase in total cell numbers and a decrease in the apoptosis rate compared to the control.Measurements on D2 and D6 revealed that embryos with Lut supplementation had lower ROS levels and higher glutathione levels compared to the control.Moreover,Lut supplementation significantly augmented mitochondrial content and membrane potential.Intriguingly,activation of the Nrf2/Keap1 signaling pathway was observed in embryos supplemented with Lut,leading to the upregulation of antioxidant-related gene transcription levels.To further validate the relationship between the Nrf2/Keap1 signaling pathway and effects of Lut in porcine embryonic development,we cultured PA embryos in a medium supplemented with brusatol,with or without the inclusion of Lut.The positive effects of Lut on developmental competence were negated by brusatol treatment.Conclusions Our findings indicate that Lut-mediated activation of the Nrf2/Keap1 signaling pathway contributes to the enhanced production of porcine embryos with high developmental competence,and offers insight into the mechanisms regulating early embryonic development.

Effect of coenzyme Q10 supplementation on post-vitrification mouse embryo development

Objective:To investigate the effects of coenzyme Q10(CoQ10)supplementation on post-vitrification embryo development and gross morphology.Methods:Balb/c mouse embryos were cultured in potassium simplex optimised medium(KSOM)with varying CoQ10 concentrations[0(control),20,40,and 60μM].The most effective CoQ10 concentration(40μM)was selected for subsequent post-vitrification morphology study.Embryos were randomly divided into four groups:Group A(non-vitrified without CoQ10),Group B(non-vitrified with CoQ10),Group C(vitrified without CoQ10),and Group D(vitrified with CoQ10),followed by vitrification at the 8-cell stage.Survival rates and development until the blastocyst stage were evaluated through morphological examinations using ASEBIR's system,distinguishing normal and abnormal embryos.Results:Supplementation of 40μM CoQ10 significantly increased blastocyst formation(95%)compared to the control group(92%),20μM(62%),and 60μM(56%)(P<0.001).Following vitrification,Group D exhibited a significant increase in blastocyst formation(92%)compared to Group C(82%)(P<0.05).Morphological assessments indicated superior embryo quality in Group B over Group D during the cleavage stage,morula,and blastocyst(P<0.05).Conclusions:CoQ10 supplementation exhibits promising potential to enhance preimplantation embryo development,increase blastocyst formation rates,and improve embryo quality post-vitrification.This offers a promising approach to mitigate oxidative stress on embryos,potentially improving overall assisted reproductive technology outcomes.

Anethole improves the developmental competence of porcine embryos by reducing oxidative stress via the sonic hedgehog signaling pathway

Background Anethole(AN)is an organic antioxidant compound with a benzene ring and is expected to have a positive impact on early embryogenesis in mammals.However,no study has examined the effect of AN on porcine embryonic development.Therefore,we investigated the effect of AN on the development of porcine embryos and the underlying mechanism.Results We cultured porcine in vitro-fertilized embryos in medium with AN(0,0.3,0.5,and 1 mg/mL)for 6 d.AN at 0.5 mg/mL significantly increased the blastocyst formation rate,trophectoderm cell number,and cellular survival rate compared to the control.AN-supplemented embryos exhibited significantly lower reactive oxygen species levels and higher glutathione levels than the control.Moreover,AN significantly improved the quantity of mitochondria and mitochondrial membrane potential,and increased the lipid droplet,fatty acid,and ATP levels.Interestingly,the levels of proteins and genes related to the sonic hedgehog(SHH)signaling pathway were significantly increased by AN.Conclusions These results revealed that AN improved the developmental competence of porcine preimplantation embryos by activating SHH signaling against oxidative stress and could be used for large-scale production of high-quality porcine embryos.

Extracellular vesicles from oviductal and uterine fluids supplementation in sequential in vitro culture improves bovine embryo quality

Background:In vitro production of bovine embryos is a well-established technology,but the in vitro culture(IVC)system still warrants improvements,especially regarding embryo quality.This study aimed to evaluate the effect of extracellular vesicles(EVs)isolated from oviductal(OF)and uterine fluid(UF)in sequential IVC on the development and quality of bovine embryos.Zygotes were cultured in SOF supplemented with either BSA or EVs-depleted fetal calf serum(dFCS)in the presence(BSA-EV and dFCS-EV)or absence of EVs from OF(D1 to D4)and UF(D5 to D8),mimicking in vivo conditions.EVs from oviducts(early luteal phase)and uterine horns(mid-luteal phase)from slaughtered heifers were isolated by size exclusion chromatography.Blastocyst rate was recorded on days 7-8 and their quality was assessed based on lipid contents,mitochondrial activity and total cell numbers,as well as survival rate after vitrification.Relative mRNA abundance for lipid metabolism-related transcripts and levels of phosphorylated hormonesensitive lipase(pHSL)proteins were also determined.Additionally,the expression levels of 383 miRNA in OF-and UF-EVs were assessed by qRT-PCR.Results:Blastocyst yield was lower(P<0.05)in BSA treatments compared with dFCS treatments.Survival rates after vitrification/warming were improved in dFCS-EVs(P<0.05).EVs increased(P<0.05)blastocysts total cell number in dFCS-EV and BSA-EV compared with respective controls(dFCS and BSA),while lipid content was decreased in dFCSEV(P<0.05)and mitochondrial activity did not change(P>0.05).Lipid metabolism transcripts were affected by EVs and showed interaction with type of protein source in medium(PPARGC1B,LDLR,CD36,FASN and PNPLA2,P<0.05).Levels of pHSL were lower in dFCS(P<0.05).Twenty miRNA were differentially expressed between OF-and UF-EVs and only bta-miR-148b was increased in OF-EVs(P<0.05).Conclusions:Mimicking physiological conditions using EVs from OF and UF in sequential IVC does not affect embryo development but improves blastocyst quality regarding survival rate after vitrification/warming,total cell number,lipid content,and relative changes in expression of lipid metabolism transcripts and lipase activation.Finally,EVs miRNA contents may contribute to the observed effects.

The Quality Characteristics of Eggs: Impact on the Volume of Allantoin-Amniotic Fluid of Chicken Embryos

In this paper, the eggs＇ weight, quality characteristics （ albumen density, shell quality, yolk size）, and egg weight loss during incubation having impact on volume of allantoin-anmiotic fluid are considered. The major parameters that should be taken into account when creating specialized population of chickens for the production of DEC （ developing embryos of chickens） are determined.

Beneficial role of melatonin in protecting mammalian gametes and embryos from oxidative damage

Mammalian gametes and embryos are particularly vulnerable to oxidative stress-induced damage, which is mainly caused by reactive oxygen species（ROS） originating from normal metabolism and/or the external environment. Several researchers have implicated the role of oxidative stress in the activation of apoptosis, causing peroxidative damage to sperms/oocytes and inducing embryo fragmentation, arrest, or demise. Melatonin is a tryptophan derivative that is known for its powerful free radical-scavenging activity and broad-spectrum antioxidant property. Numerous studies have shown that melatonin and its metabolic derivatives can sequentially detoxify ROS in an antioxidant cascade, and modulate various antioxidant enzymes via its receptors to prevent radical-mediated damage. The identification of melatonin receptors in cumulus/granulosa cells, oocytes, and epididymal tissues implies that melatonin has protective actions on gametes and embryos. Enriching the semen extender or culture medium with melatonin significantly benefits sperm characteristics, improves oocyte maturation potential and quality, and enhances the developmental competence of preimplantation embryos. Certainly, further comparative studies are needed to show the unique antioxidant role and the advantage of melatonin in this field. This review summarizes the harmful effects of ROS and the beneficial role of melatonin against oxidative damage of gametes and embryos.

Effect of Swim-Up and Percoll Treatment on Sperm Quality and In vitro Embryo Development in Yak

This study was designed to determine the effect of different sperm preparation treatments on yak sperm quality and in vitro embryo development.Frozen-thawed semen samples were treated using swim-up or percoll gradient centrifugation methods.Sperm concentration,progressive motility,recovery of motile sperm,membrane integrity,acrosome and chromatin integrity were scored and compared in recovered samples and controls.In addition,the effects of two sperm separation treatments on embryos capable of cleavage and in vitro development to the blastocyst stage were evaluated.Swim-up separated sperm showed a higher motility,while the concentration of spermatozoa recovered and percent recovery of motile sperm were higher with percoll gradient centrifugation separation.According to the optical and electron microscopies,swim-up produced higher percentage of sperm with intact plasma membrane and acrosome than percoll gradient centrifugation separation.However,there was no difference in the percentage of sperm with intact chromatin between two treatment groups.Cell numbers in the blastocysts of two groups were not different.The blastocyst rate was similar in both groups,whereas cleavage rate was higher when swim-up was used.

Impact of Veratrum nigrum L.and Euphorbia fischeriana steud.on Embryo Development of Cattle in Sanjiang Area

It is very important to find out the reasons and the morphological changes of cattle abortion, death embryo and teratism in Sanjiang area, in order to determine the preventive measures, to improve animal quality, and to accelerate the animal industry. In the present studies, 25 cows and 25 local bos calves were investigated. The powder of Veratrum nigrum L. and Euphorbia fischeriana steud. was medicated to the animals during the 15 - 19th day of gestation. It was found that there were different poisoning reactions. When the poisoning was on the 15 - 16th day of gestation, the pregnant animals were easy to miscarriage. When the poisoning was on the 17 - 18th day of gestation, the embryos were easy to become teratism. The joint malformation bicephalus and rachischisis could take place for calves. If the poisoning was after 19th day of gestation , there were much more death embryos. The results of the studies showed that Veratrum and Euphorbia fischeriana steud. were the most poisonous plants to the animal industry of Sanjiang area. Some preventive measures were proposed.

Comparative Embryological Studies on Infertility of Interspecific Hybridizations Between Oryza sativa with Different Ploidy Levels and O. officinalis

As maternal parents, diploid （L202-2x） and autotetraploid （L202-4x） of Oryza sativa cv. L2O2 were crossed with O. officinalis. Embryo development and fertilization in these two crosses were comparatively studied. There were no mature hybrid seeds obtained because all the hybridized spikelets died 30 days after pollination. The main reasons for no seed set were abnormal fertilization and development of the embryos and endosperms in the interspecific hybrids. There were doublefertilization, egg cell single-fertilization and non-fertilization in these crosses. Although 59.45% and 54.87% of hybrid embryos produced in the crosses of L202-2x/O. officinalis and L202-4x/O. officinalis, respectively, hybrid embryos ceased to develop or degenerated and plenty of free endosperm nuclei were in disaggregating state without developing cellular endosperms three days after pollination. Besides, some embryological differences in these two crosses were found, that is, the rate of double-fertilization and total rate of doubleand single-fertilization in L202-2x/O. officinalis were higher than those in L202-4x/O. officinalis. The embryo and endosperm of hybrids developed more slowly, and embryos and free endosperm nuclei were more severely degenerated in L202-4x/O. officinalis than in L202-2x/O. officinalis. Five days after pollination, a few of embryos in L202-2x/O. officinalis developed into pear-shaped ones, however, embryos in L202-4x/O. officinalis were all degenerated. Therefore, it is more difficult to obtain interspecific hybrids by wide crosses between autotetraploid of O. sativa and O. officinalis.

Relationship between Different Pronuclear Patterns and Potential of Embryo Development and Pregnancy

Objective To explore the relationship between the patterns of pronucleus and embryo development and pregnancy potential in the pronuclear stageMethods According to the number and distribution of nucleolar precursor bodies, the embryos at pronuclear stage were classified into 6 pronuclear patterns from 0 to 5, 16 - 18 h after in vitro fertilization (IV F) or intracytoplasmic sperm injection (ICSI). For each, pattern, the subsequent embryonic morphology and the pregnancy rate were analyzed.Results Embryos of Pattern 0 developed to significantly more embryos with good quality and higher pregnancy potential than the embryos developing from other patterns (83. 14% and 76. 11% respectively, P<0. 05). The pregnancy rate was decreased as less embryos of Pattern 0 were transferred . The pregnancy rate of the groups of only Pattern 0, with Pattern 0, and without Pattern 0 were 48. 08% , 32. 14% and 21. 28% respectively (P<0. 05).Conclusions The pronuclear patterns are of the predictive value of embryo development and pregnancy potential, which can be used as a new tool for the selection of embryos in IVF and ICSI.

Effects of Exogenous Carbon Monoxide Releasing Molecules on the Development of Zebrafish Embryos and Larvae

The use of exogenous carbon monoxide releasing molecules（CORMs）provides promise for clinical application;however,the hazard potential of CORMs in vivo remains poorly understood.The developmental toxicity of CORM-3 was investigated by exposure to concentrations ranging from 6.25 to400μmol/L during 4-144 h post fertilization.Toxicity endpoints of mortality,spontaneous movement,heart rate,hatching rate,malformation,body length,and larval behavior were measured.

Ultrastructural changes in embryoic neuroepithelial cells caused by passive smoking in golden hamsters at different periods of pregnancy: A randomized controlled trial

BACKGROUND： Tobacco smoke exposure is recognized as a health risk for pregnant women and it is increasingly evident that tobacco smoke affects the development of brain. Recently, associations between maternal smoking during pregnancy and subsequent mental health problems in offspring have been reported. OBJECTIVE： To observe the effect of passive smoking on the morphology of nerve tissues and the ultrastructure of neuroepithelial cells during embryogenesis in golden hamster at different pregnant period. DESIGN： A randomized control study. SETTING： Department of Histology and embryology, Qingdao University. MATERIALS： Adult golden hamsters, including 40 males and 40 females that had not delivered, weighing （105±5） g, were provided by Shenyang Changsheng Biotechnology, Co.,Ltd. At 20 ： 00 - 21 ： 00, one male and one female were matched in each cage, and their mating was observed. The vaginal swabs were examined the next day and the day of positive sperm was taken as embryonic day 1 （E1）. METHODS： The experiment was completed in the Department of Histology and Embryology of Qingdao University from September 2001 to September 2003. （1） Abnormality caused by smoking, grouping and model establishment： A total of 40 healthy pregnant golden hamsters were randomly divided into control group （n =20） and experimental group （n =20）. The hamsters in the experimental group were exposed to tobacco smoke from embryonic day 4 to 7, 3 times per day, continuously 1 hour per time, 1 cigarette per golden hamster, for 4 consecutive days in the self-made chamber. The animals in the control group were given the same conditions as those in the experimental group except exposure to smoke. （2） Observation with transmission electron microscope： According to different gestational ages, the experimental group and the control group were all divided 4 subgroups （Groups A, B, C and D） respectively, and 5 hamsters in each subgroup. The pregnant golden hamsters were anaesthetized with 1 g/L pentobarbital sodium at 12 ： 00 and 18 ： 00 at E8, 8 ： 00 at E9 and 8 ： 00 at E10, and all the pregnant uteruses were divulsed under the stereomicroscope. The development of the neural plate, neural groove and neural tube were observed. Meanwhile, the amount of normal embryos and abnormal embryos including the neural tube defect ratios were recorded. （3） Electron microscopic specimen preparation and observation： Three embryos of each group ad libtium were fixed. The alternations of neuroepithelial ultrastrnctures were observed with transmission and scanning electron microscopes. MAIN OUTCOME MEASURES： （1） The incidences of abnormality of nervous system development were observed under stereomicroscope and scanning electron microscope in smoking group and the control group; （2） Alternations of neuroepithelial ultrastructures were observed with transmission electron microscope. RESULTS： All the 40 pregnant golden hamsters were involved in the final analysis. （1） Manifestations and incidence of nervous system dysplasia： Passive smoking could induce dymorphogenesis during neurnlation, which mainly presented as growth retardation, spina bifida and failure of formation of neural tubes; The incidences of the nervous system dysplasia in the experimental groups [20%（10/49）, 27%（14/51）, 32% （19/59）, 27% （17/63）] were higher than those in the corresponding control groups [0. 2% （1/57）, 4% （2/53）, 4% （2/52）, P 〈 0.01]. （2） Histomorphological changes at different time points after spermatiation observed with transmission and scanning electron microscopes： In the control group, the embryos formed C-shape columned embryos, anterior and posterior neuropores were all closure at 10 ： 00 on E10; In the experimental group, unfused anterior and posterior neuropores still could be found, and some embryos presented spina bifida at 10 ： 00 on E10. In the control group, neuroepithelial cell arranged tidily and closely, the boundary of the cells was clear, the flee surface of neuroepithelial had a mass of long and regular microvillus, and the surface of mesenchymal cell around the neuroepithelium had many processes which mutually related at 12 ： 00 on E8. In the experimental group, the neuroepithelial cells arranged irregularly and the intercellular spaces became wide at 12 ： 00 on E8. The apical portion of many neuroepithelial cells bulged into the lumen and many microvilli were shorted and swollen. The quantity of the microvillus reduced gradually, evenly disappeared with the increasing of gestational age at 18：00 on E8. Under transmission electron microscope, the neuroepithelial cells in experimental embryos arranged irregularly. There were many visible materials in the intercellular space which increased the breadth and anomaly. It was apparent that passive smoking evoked major alterations in neuroepithelial cytoarchitecture. Junctional complex reduced. Many microvilli were shorted and swollen, even the apical portion of many neuroepithelial cells bulged, and abscised into the lumen. A lot of vacuolation appeared in the cytoplasm of neuroepithelia and mesenchymal cell around the neuroepithelium. The cristae of mitochondria reduced even disappeared, and some mitochondria became elongate. Irregular nuclear, increased heterochromatin and karyopycnosis/karyorrhexis were observed easily. Perinuclear cisternae partially swelled and embraced tangible material （maybe the material from nuclear）. Some death cells separated into a lot of apoptotic bodies. Some apoptotic bodies were found in the cytoplasm of other healthy-looking or healthy cells. CONCLUSION： Passive smoking may induce degeneration, apoptosis, and cells loss in the neural epithelium, thereby result in failure of formation and differentiation of neural tube. It is an important way by which passive smoking caused neural tube defects.

Research on the appropriate way to transfer exogenous substances into chicken embryos

In biological research, chicken embryos are a classic experimental model for the exploration of the embryonic development and cell differentiation. Transferring exogenous substances into chicken embryos for producing medical antibodies has been widely used in the production practice. However, there are few studies about the effect of the different injection site and dosage on chicken embryos. The aim of this study was to explore the effects of different injection sites and dosages on chicken embryo hatching rate and development, so as to provide a basis for further studies using the chicken embryo model. Freshly laid eggs （Rugao yellow chicken） were injected with different doses of saline at the tip, equatorial plane and the blunt end of the egg shell, respectively. Egg hatching rate was recorded and compared among injection sites and different doses. A trypan blue stain was also injected at the aforementioned sites and the growth of chicken embryos was observed. The SPSS （statistical package for the social science） software was used to analyze the relationship between the chicken eggs hatching rate and the different injection sites or the different dosages. The experimental results showed that there were significant differences on egg hatching rates among the different injection sites and doses （P〈0.05）. The hatchability of the blunt end injection group was significantly higher than that of the other two sites. The egg hatching rate decreased with increased saline doses. The egg hatching rate of the 100 pL saline injection group was higher than the 200 and 300 μL dosage groups. Ultimately, we suggest that the optimal chicken embryo injection process is during early development, at the blunt end site with a dose less than 100 μL to minimize damage to the egg.

Alteration of ERβ gene Rsal polymorphism may contribute to reduced fertilization rate and embryonic developmental competence

This paper aims to determine the possible role of estrogen receptor-β （ERβ） gene Rsal polymorphism on sperm fertility and early embryonic development in humans. Three groups of Chinese men were recruited： in vitro fertilization （IVF） group, including 374 couples who underwent conventional IVF; intracytoplasmic sperm injection （ICSI） group, including 294 couples who underwent an ICSI procedure using ejaculated sperm; and azoospermic group, consisting of 197 couples who underwent ICSI using either testis or epididymis sperm. Rsal polymorphism in the ERβ gene was detected by polymerase chain reaction （PCR）-restriction fragment length polymorphism technique; fertilization and high-quality embryo rates were evaluated for each group. In each group, no significant differences were found in the overall rates of fertilization and high-quality embryos among GG, AG and AA genotypes. However, the proportion of cycles possessing a satisfactory high-quality embryo rate with the AA genotype was significantly lower than that in the wild-type GG genotype from each group. These results demonstrated that sperm possessing the ERβ RsalA genotype may have reduced fertilization ability and decreased early embryonic developmental potential, which could directly or indirectly contribute to the low fertilization rate and early embryonic developmental arrest in some cases.

Effect of royal jelly on in vitro fertilization and early embryo development following nicotine treatment in adult female rats

Objective:To scrutinize the protective role of royal jelly as an antioxidant on nicotine-induced changes in malondialdehyde(MDA)level,p53 expression,in vitro fertilization(IVF)rate,and early embryo development in adult female rats.Methods:A total of 56 adult female Wistar rats were divided into 8 groups(n=7 in each group).Group 1 served as an untreated control group,group 2,3 and 4 received nicotine at a dose of 0.50,1.00 and 2.00 mg/kg respectively,group 5 received royal jelly at a dose of 100.00 mg/kg,and group 6,7 and 8 received 0.50,1.00 and 2.00 mg/kg nicotine,respectively,with 100.00 mg/kg body weight royal jelly.Nicotine and royal jelly were administered daily for 49 days in the experimental groups intra-peritoneally and orally,respectively.At the end of the experimental period,p53 expression,IVF rate and early embryo development as well as MDA concentration were measured.Results:The IVF rate,number of cumulus oocytes,two-cell embryos and blastocysts decreased in the nicotine-treated groups in a dose-dependent manner.In addition,p53 mRNA expression and MDA levels increased in the nicotine-treated groups.Royal jelly co-administration led to partial improvement in the aforementioned parameters.Conclusions:Royal jelly may have a repro-protective effect in nicotine-administered female rats in terms of its anti-oxidant and anti-apoptotic properties.

Influence of Different Quality Sperm on Early Embryo Morphokinetic Parameters and Cleavage Patterns:A Retrospective Time-lapse Study

To investigate whether sperm with low concentration and motility can impact preimplantation embryos and to analyze how the effects present under a time-lapse incubation system,2905 oocytes were collected from 219 couples between January 2014 and December 2015.Patients were divided into three groups according to sperm quality.Morphokinetic parameters and six cleavage patterns in the initial three cleavages were evaluated using the Primo Vision system.Embryo quality and clinic outcomes such as implantation rate,pregnancy rate and live birth rate were measured.The results showed that the concentration and motility of sperm correlated strongly with the rate of 2PN embryos,good-quality embryos on D3,blastocysts on D5/6 and good quality embryos on D5/6.The time-lapse system recordings showed that compromised sperm quality could result in a significant delay in cc l and a decrease in cc2,and impact embryo developmental potential mainly through large fragments or/and blastomere fragmentation in the initial three cleavages.In conclusion,sperm with low concentration and motility can have paternal effects on preimplantation embryos.These paternal effects present both as changes in morphokinetic parameters and cleavage patterns,which occur as early as fertilization and may cause severe damage to the preimplantation embryos.

Presence of Meiotic Spindles Indicates Early Cleavage of Embryos

Objective To assess whether the detection of the meiotic spindle could anticipate the appearance of early cleavage. Methods Oocytes were obtained from stimulated ovaries of consenting patients undergoing oocytes retrieval for ICSI. Spindles were imaged with the Polscope. After ICSI, oocytes with or without spindles were cultured for examination of early cleavage and embryo development. A total of 328 oocytes from 50 cycles were examined with the Polscope and inseminated by ICSI. Results Spindles were imaged in 81.7% of oocytes. After ICSI, more oocytes with spindles （78.4%） fertilized normally than oocytes without spindles （53.3%） （P〈0. 001）. At 25-27 h post ICSI, more fertilized oocytes developed from oocytes with spindles （81.9%） were detected early cleavage than those from oocytes without spindles （28.1%） （P〈0.001）. Significantly more embryos with early cleavage （82.2%） developed to high quality embryos at d 3 compared with the embryos without early cleavage （48.3%） （P=0.001）. The value of rs related to the relationship between spindles and early cleavage was 0.420 （P〈0.001）. Conclusion The existing of the early cleavage may have a predictive value on the opportunity of high quality embryos and the existing of the spindle may have a predictive value in the appearance of early cleavage.

Current and future therapies for abnormal early embryogenesis with assisted reproductive technology

Each stage of embryonic development,including normal gamete maturation,fertilization,zygotic genome activation,and cleavage,is crucial for human reproduction.Early embryo arrest is a common phenomenon.It is estimated that about 40%–70%of human embryos are arrested at early developmental stages.However,the exact mechanism remains largely uncertain.Embryos can be investigated in vitro by way of the development of in vitro fertilization/intracytoplasmic sperm injection.In addition to iatrogenic factors related to abnormal oocyte/embryo development,multiple gene mutations have been found to be involved in such phenotypes.Based on the knowledge of known etiological factors,several therapies are proposed to improve clinical outcomes.Here,we shed light on current and potential therapies for treating these conditions through reviewing articles and combining with our clinical and research experience.

Effects of Feeding OmniGen-AF^®during Superovulation on <i>in Vitro</i>Development of Embryos Recovered from Donor Beef Cows

Embryo quality is crucial when selecting embryos for transfer. Variation in quality may be attributed to poor oocytes, semen, stress, inflammation, and potential immune system dysregulation. OmniGen-AF® (OG) feeding supports immune system function and animal health. Our laboratory recently reported lower percent degenerate embryos recovered and increased plasma progesterone in beef cattle donors fed OG during superovulation. In vitro development of embryos recovered from donor cows fed OG prior to collection is presented here. Embryos were recovered from 24 beef cows assigned to four treatment groups: 0 g OG/hd/d and 200 mg Folltropin®-V (FSH) (0/200);0 g OG/hd/d and 400 mg FSH (0/400), 56 g OG/hd/d, 200 mg FSH (56/200) and 56 g OG/hd/d and 400 mg FSH (56/400). Good to excellent quality early blastocysts were cultured for 8 d. and development through hatching, embryonic volume and plasminogen activator (PA) production were quantified. The complete protocol was repeated 90 - 120 d later as Replicate 2. Optimal development was observed by embryos recovered from 0/200 cows where percent blastocysts hatching was greater (P < 0.05) compared to 56/200 and 0/400 cows and embryonic volume was greatest (P < 0.05) in Replicate 1. However, percent blastocysts hatching from 0/200 cows was similar (P > 0.10) to 56/400 cows and embryos recovered from 56/400 cows in Replicate 1 produced more (P < 0.05) PA compared to all other groups. For cows superovulated with the standard 400-mg FSH dose, feeding OG supported in vitro embryo development similar to that observed for 0/200 cows.

Effect of Oocyte Recovery Techniques on in Vitro Production of Swine Embryos

In Vitro production of swine embryos is a valuable tool to generate clones and genetically modified pigs during a short period of time. However, the efficiency of the existing methods is extremely low and the oocyte quality and quantity represent important obstacles on the success of in Vitro production of embryos. Therefore, the aim of this study was to compare the in Vitro maturation, fertilization and subsequent embryo development rates of oocytes recovered by ovary slicing or follicular aspiration. The oocyte recovery rate (grade 1 COC/ovary) was higher (p = 0.0083) in the slicing group when compared to the aspiration group. No differences were observed between groups regarding in Vitro maturation and early cleavage rates. A higher percentage of oocytes recovered by follicular aspiration reached the blastocyst stage after IVF when compared to the ovary slicing method (p = 0.0395). However, no difference on blastocyst cell number was observed. Although the recovery of oocytes using the slicing technique yielded more grade 1 oocytes per ovary than the aspiration method, the number of oocytes that reached the blastocyst stage after IVF by the slicing method was lower when compared with oocytes obtained by aspiration, as observed by lower blastocyst rates. In conclusion, the follicular aspiration is the method of choice for porcine in Vitro embryo production.