117 EFFECT OF DIFFERENT CRYOPRESERVATION METHODS ON THE QUALITY OF IN VITRO-PRODUCED BOVINE EMBRYOS

2010 ◽  
Vol 22 (1) ◽  
pp. 217
Author(s):  
H. Stinshoff ◽  
K. Brüning ◽  
A. Hanstedt ◽  
D. Müller ◽  
S. Wilkening ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Mrna Expression ◽  
Control Group ◽  
Bovine Embryos ◽  
In Vitro Production ◽  
Glut 1 ◽  
Gene Transcripts

In vitro production (IVP) of bovine embryos has been greatly improved over the last couple of years. However, only one-third of the total number of embryos transferred worldwide are of in vitro origin. The IVP embryos still show remarkable differences compared with their in vivo-derived counterparts (i.e. bovine embryos produced in vitro are more sensitive to cryopreservation). So far, vitrification seems to be the most promising method to cryopreserve in vitro-produced bovine embryos. The aim of this study was to determine the effect of 2 different cryopreservation methods on the quality of in vitro-produced bovine embryos at the molecular level using a sensitive RT-qPCR assay. Bovine blastocysts were produced using abattoir ovaries and a standard protocol for IVP (Wrenzycki et al. 2001). They were randomly vitrified employing PBS plus ethylene glycol and DMSO or cryopreserved using a programmable freezer and 1.5 M ethylene glycol. After thawing, embryos from both groups were cultured for 48 h. After 24 h of culture re-expansion rates were documented, and after 48 h hatching rates were documented. After hatching, blastocysts were stored at -80°C for subsequent RT-qPCR analysis. The following gene transcripts known to play important roles during preimplantation development were analyzed: HSP70, GLUT-1, GLUT-3, E-CAD, ZO-1, DNMT3a, IFNτ, DCII. Re-expansion rates were 74.7% (68/91) and 75.0% (87/116) for vitrified and conventionally cryopreserved blastocysts, and 57.1% (52/91) and 55.2% (64/116) of re-expanded embryos hatched. The relative abundances of HSP70, GLUT-1, and ZO-1 transcripts were significantly affected in both groups of cryopreservation compared with the control group (hatched blastocysts without cryopreservation). Conventional cryopreservation had a significant effect on the amount of GLUT-3, DNMT3a, and IFNτ mRNA, whereas vitrification significantly affected DCII transcripts. E-CAD mRNA expression was similar in all groups of embryos. These results suggest that not only the cryopreservation process itself but also the method used to freeze the embryos had a significant influence on the mRNA expression of developmentally important genes in hatched bovine blastocysts. The support of the H.W. Schaumann Stiftung (Germany) and Gynemed Medizinprodukte GmbH & Co. KG (Germany) is gratefully acknowledged.

Effects of bovine oviduct epithelial cells, fetal calf serum and bovine serum albumin on gene expression in single bovine embryos produced in the synthetic oviduct fluid culture system

2005 ◽  
Vol 17 (8) ◽  
pp. 751 ◽  
Author(s):  
Mona E. Pedersen ◽  
Øzen Banu Øzdas ◽  
Wenche Farstad ◽  
Aage Tverdal ◽  
Ingrid Olsaker
Keyword(s):  
Gene Expression ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Developmental Competence ◽  
Bovine Embryos ◽  
Glut 1 ◽  
Significant Difference ◽  
Oviduct Fluid

In this study the synthetic oviduct fluid (SOF) system with bovine oviduct epithelial cell (BOEC) co-culture is compared with an SOF system with common protein supplements. One thousand six hundred bovine embryos were cultured in SOF media supplemented with BOEC, fetal calf serum (FCS) and bovine serum albumin (BSA). Eight different culture groups were assigned according to the different supplementation factors. Developmental competence and the expression levels of five genes, namely glucose transporter-1 (Glut-1), heat shock protein 70 (HSP), connexin43 (Cx43), β-actin (ACTB) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH), analysed as mRNA by using reverse transcription–polymerase chain reaction, were measured on bovine embryos cultured for 9 days. Gene expression of these in vitro-produced embryos was compared with the gene expression of in vivo-produced embryos. There was no significant difference found in embryo developmental competence between the Day 9 embryos in BOEC co-culture, FCS and BSA supplements in SOF media. However, differences in gene expression were observed. With respect to gene expression in in vivo and in vitro embryos, BOEC co-culture affected the same genes as did supplementation with FCS and BSA. HSP was the only gene that differed significantly between in vitro and in vivo embryos. When the different in vitro groups were compared, a significant difference between the BOEC co-culture and the FCS supplementation groups due to Glut-1 expression was observed.

scholarly journals In vivo culture of bovine embryos and quality assessment of in vivo vs. in vitro produced embryos

2012 ◽  
Vol 50 (No. 4) ◽  
pp. 149-158 ◽  
Author(s):  
V. Havlicek ◽  
M. Lopatarova ◽  
S. Cech ◽  
R. Dolezel ◽  
T. Huber ◽  
...  
Keyword(s):  
Quality Assessment ◽  
Recovery Rate ◽  
Bovine Embryos ◽  
In Vivo Culture ◽  
Blastocyst Rate ◽  
Culture Procedure ◽  
Recovery Methods

Routine access to the bovine oviduct for in vivo culture accomplishes various demands on embryo production for scientific as well as commercial purposes. The experiments conducted in the present study focused on the efficiency of recovery methods after temporary in vivo culture of bovine embryos in oviducts of the homologous species using transvaginal endoscopy (Experiment I) and on the quality assessment of recovered blastocysts (Experiment II). In Experiment I in vitro matured oocytes were fertilized, cultured for 1 to 3 days and transferred unilaterally into the ipsilateral oviducts of 54 heifers by the means of transvaginal endoscopy. After 4 to 6 days of in vivo culture embryos were re-collected either by non-surgical flushing of uterine horns (U-group) or by combined flushing of the oviducts and uterine horns (OU-group). In total the recovery rate was 38.4% (780/2029). After flushing at day seven, 106 blastocysts (blastocyst rate: 13.6% ) were found. The additional 24 h of in vitro culture (day eight) resulted in 153 blastocysts (blastocyst rate: 19.6% ). The recovery rate in the OU-group was twice as efficient as in the U-group (390/1358 vs. 390/671, P < 0.01). The recovery rates among the different stages of transferred embryos did not differ significantly; likewise cross-effects among the stages and the recovery methods were non-significant. The recovery methods (P < 0.001) and the interaction between the recovery methods and the stages of transferred embryos (P < 0.01) had an influence on blastocyst yields on day seven (U-group 37/1358 vs. OU-group 69/671) and day eight (U-group 48/1358 vs. OU-group 105/671). In Experiment II embryo quality was assessed by the survival rate of blastocysts after freezing in ethylene glycol. Day seven embryos were produced in vitro (in vitro group D7) or by IVM/IVF followed by a combined culture procedure (2 to 3 days in vitro prior to 4 to 5 days in vivo) (in vivo group D7) or after superovulation and collection at day seven (superovulation group). Embryos from in vitro group D7 re-expanded only for 6 h after thawing, embryos from in vivo group D7 and superovulation group were alive for 24 h and 72 h of culture, respectively. Only embryos derived by superovulation showed hatching activity. Blastocysts from the in vitro group D7 and the in vivo group D7 that were held in culture medium for additional 24 h (day eight) showed an analogous post-thawing culture behaviour. In conclusion, the results of the present study demonstrated that some embryos transferred for in vivo culture remain in the oviduct even at day seven. Hence, combined flushing of oviducts and uterine horns after in vivo culture in the bovine oviduct is necessary for effective embryo re-collection. The quality of recovered embryos after temporary in vivo culture assessed by cryotolerance was in-between those produced in vitro or recovered after superovulation.

In vitro and in vivo culture effects on mRNA expression of genes involved in metabolism and apoptosis in bovine embryos

2005 ◽  
Vol 17 (8) ◽  
pp. 775 ◽  
Author(s):  
Hiemke M. Knijn ◽  
Christine Wrenzycki ◽  
Peter J. M. Hendriksen ◽  
Peter L. A. M. Vos ◽  
Elly C. Zeinstra ◽  
...  
Keyword(s):  
Glucose Metabolism ◽  
Mrna Expression ◽  
Critical Period ◽  
Glucose Transporter ◽  
Expression Patterns ◽  
Culture Conditions ◽  
Glut 4 ◽  
Gene Transcripts

Bovine blastocysts produced in vitro differ substantially from their in vivo-derived counterparts with regard to glucose metabolism, level of apoptosis and mRNA expression patterns. Maternal embryonic genomic transition is a critical period in which these changes could be induced. The goals of the present study were twofold: (1) to identify the critical period of culture during which the differences in expression of gene transcripts involved in glucose metabolism are induced; and (2) to identify gene transcripts involved in apoptosis that are differentially expressed in in vitro- and in vivo-produced blastocysts. Relative abundances of transcripts for the glucose transporters Glut-1, Glut-3, Glut-4 and Glut-8, and transcripts involved in the apoptotic cascade, including BAX, BCL-XL, XIAP and HSP 70.1, were analysed by a semiquantitative reverse transcription–polymerase chain reaction assay in single blastocysts produced in vitro or in vivo for specific time intervals, that is, before or after maternal embryonic transition. Whether the culture environment was in vitro or in vivo affected the expression of glucose transporter transcripts Glut-3, Glut-4 and Glut-8. However, the critical period during culture responsible for these changes, before or after maternal embryonic transition, could not be determined. With the exception of XIAP, no effects of culture system on the mRNA expression patterns of BAX, BCL-XL and HSP 70.1 could be observed. These data show that expression of XIAP transcripts in expanded blastocysts is affected by in vitro culture. These findings add to the list of bovine genes aberrantly expressed in culture conditions, but do not support the hypothesis that maternal embryonic transition is critical in inducing the aberrations in gene expression patterns studied here.

239 USE OF CYCLIC ADENOSINE MONOPHOSPHATE MODULATORS IN IN VITRO PRODUCTION OF BOVINE EMBRYOS

2015 ◽  
Vol 27 (1) ◽  
pp. 209
Author(s):  
T. Fanti ◽  
N. M. Ortega ◽  
R. Garaguso ◽  
M. J. Franco ◽  
C. Herrera ◽  
...  
Keyword(s):  
Phosphodiesterase Inhibitor ◽  
Basal Medium ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Control Group ◽  
Hatching Rate ◽  
Bovine Embryos ◽  
Oocyte Competence

In vitro embryo production systems (IVP) try to emulate and enhance molecular events that occur in in vivo reproductive systems in order to increase, not only the number of embryos generated, but also their quality. Despite advances, IVP processes are still inefficient compared with in vivo systems. Several studies have attributed this deficiency to a lack of oocyte competence due to spontaneous premature resumption of meiotic maturation in the oocyte following the removal from its follicular environment. Therefore, our objective was to increase oocyte competence avoiding premature resumption of meiosis by using cyclic adenosine monophosphate modulators. Cumulus-oocyte complexes (COC) were obtained from ovaries of slaughterhouses, washed, and randomly allocated in 2 culture systems. Oocytes in the control group (IVM) were cultured for a period of 24 h in basal medium TCM-199 with EGF (1 µg mL–1) supplemented with rhFSH (25 mIU mL–1). Oocytes in the biphasic in vitro maturation (b-IVM) group were cultured for 2 h in a basal medium supplemented with a phosphodiesterase inhibitor, 3-isobutyl-1-methylxanthine (IBMX, 500 µM), and an activator of adenylate cyclase (forskolin, 100 µM). Subsequently, COC were washed and cultured in basal medium supplemented with cilostamide (20 µM) and rhFSH (25 mIU mL–1) for 24 h. Maturation rates were analysed and IVF was performed with a dose of 1 × 106 sperm cells mL–1 in IVF-SOF medium. The presumptive zygotes were cultured in continuous-single-culture medium (Irvine) supplemented with 8 mg mL–1 of BSA until they reached the blastocyst stage. No significant differences in maturation, cleavage, and cryotolerance were observed between b-IVM and IVM groups (P > 0.05; Table 1). This study showed that b-IVM produced a significant increase in IVP compared with the control (IVM) at Days 7 and 8 (P < 0.01). Blastocyst hatching rate was significant (P < 0.05) for both treatment and day of analysis. The b-IVM group yielded an increase of 10 and 7.5% at Days 7 and 8, respectively, of IVP. The biphasic maturation showed an improvement in quality regarding the control group, in the timing analysis of production, and hatching percentages, and these results show that the use of cyclic adenosine monophosphate modulators in the oocyte maturation process enhances oocyte competence, which is reflected in increased productivity and embryo quality. We propose this treatment as an alternative to the standard protocols currently used in IVP of bovine embryos. Table 1.Effect of treatment on maturation, cleavage, and cryotolerance

60 IMPROVEMENT IN EFFICIENCY AND QUALITY OF CLONED AND PARTHENOGENETIC PORCINE EMBRYOS BY AMINO ACIDS

2007 ◽  
Vol 19 (1) ◽  
pp. 147
Author(s):  
H. T. Lee ◽  
J. M. Jang ◽  
S. H. Lee ◽  
M. K. Gupta
Keyword(s):  
Amino Acids ◽  
Culture Media ◽  
Cell Number ◽  
Control Group ◽  
In Vitro Production ◽  
Cleavage Rate ◽  
Fetal Fibroblasts ◽  
Blastocyst Rate

In vitro production of cloned porcine embryos by somatic cell nuclear transfer (SCNT) has become routine in several laboratories but the efficiency and quality of the resultant blastocysts remains sub-optimal. Cloned porcine blastocysts show low cell number, high fragmentation rate, and apoptosis which results in lower pregnancy rates upon embryo transfer. Earlier we reported that supplementation of culture media with amino acids benefit pre-implantation embryo development of in vivo- as well as in vitro-fertilized porcine embryos (Koo et al. 1997 Theriogenology 48, 791–802). This study evaluated how exogenous amino acids could affect pre-implantation development and quality of cloned or parthenogenetic porcine embryos. The effects of commercially available amino acids, referred to as Eagle&apos;s non-essential amino acids (NEAA), added or not added (control) to NCSU23 medium containing fatty acid-free BSA were studied. Oocytes recovered from abattoir-derived prepubertal porcine ovaries were matured in vitro and parthenogenetically activated (PA) or nuclear-transferred with fetal fibroblasts (SCNT), as described earlier (Uhm et al. 2000 Mol. Reprod. Dev. 57, 331–337). At 168 h post-activation, blastocysts were harvested for assessment of embryo quality by TUNEL labeling, Hoechst 33342 staining, and gene expression analysis. Results showed that, in the PA group, the cleavage rate was not affected by the supplementation of NEAA. However, the blastocyst rate was significantly improved when NEAA was present in the medium compared to that of the control group (38.9 &plusmn; 0.3 vs. 27.5 &plusmn; 0.3&percnt;, respectively) throughout the culture period. The supplementation during the pre-compaction period alone gave better results than during the post-compaction period alone (59.5 &plusmn; 0.9 vs. 33.4 &plusmn; 0.3&percnt;, respectively). In the SCNT group, however, both cleavage (73.6 &plusmn; 0.2 vs. 64.2 &plusmn; 0.4&percnt;) and blastocyst rate (18.7 &plusmn; 0.2 vs. 13.8 &plusmn; 0.3&percnt;) were improved by NEAA supplementation. Furthermore, these blastocysts had higher hatching ability (30.0 &plusmn; 1.8 vs. 14.6 &plusmn; 4.9&percnt;) than those of control group (P &lt; 0.05). Supplementation of NEAA also increased the mean nuclei number of PA-derived (76.1 &plusmn; 4.9 vs. 66.5 &plusmn; 3.3) as well as SCNT-derived (43.1 &plusmn; 2.6 vs. 31.8 &plusmn; 1.9) blastocysts and reduced the time during which blastocysts formed. TUNEL assay revealed that incidence of nuclear fragmentation and apotosis was reduced by NEAA. Real-time qRT-PCR for Bax and Bcl-XL transcripts revealed that the relative abundance of Bax was reduced while that of Bcl-XL was increased. These effects were more pronounced when NEAA was present during the pre-compaction period alone. Thus, our data suggest that NEAA improves the yield and quality of cloned porcine embryos by enhancing blastocyst expansion and positively modulating the total cell number and apoptosis. These data may have implications for understanding the nutritional needs of cloned porcine embryos produced in vitro and for optimizing the composition of culture media to support their development. This work was supported by the Research Project on the Production of Bio-Organs (No. 200503030201), Ministry of Agriculture and Forestry, Republic of Korea.

Chronically Administered Acetaminophen and the Ischemia/Reperfused Myocardium

2003 ◽  
Vol 228 (6) ◽  
pp. 674-682 ◽  
Author(s):  
R. Golfetti ◽  
T. Rork ◽  
G. Merrill
Keyword(s):  
Creatine Kinase ◽  
Tap Water ◽  
Chronic Administration ◽  
Left Ventricular ◽  
Low Flow ◽  
Control Group ◽  
Coronary Perfusion ◽  
In Vitro Production

Male and female Hartley strain guinea pigs weighing 280 ± 10 g were given acetaminophen-treated water ad libitum for 10 days. Sham-treated control animals were given similar quantities of untreated tap water (vehicle-treated control group). On Day 10, hearts were extracted, instrumented, and exposed to an ischemia (low-flow, 20 min)/reperfusion protocol. Our objective was to compare and contrast ventricular function, coronary circulation, and selected biochemical and histological indices in the two treatment groups. Left ventricular developed pressure in the early minutes of reperfusion was significantly greater in the presence of acetaminophen, e.g., at 1 min, 40 ± 4 vs 21 ± 3 mmHg ( P < 0.05). Coronary perfusion pressure was significantly less from 3 to 40 min of reperfusion in the presence of acetaminophen. Creatine kinase release in vehicle-treated hearts rose from 42 ± 14 (baseline) to 78 ± 25 units/liter by the end of ischemia. Corresponding values in acetaminophen-treated hearts were 36 ± 8 and 44 ± 14 units/liter. Acetaminophen significantly ( P < 0.05) attenuated release of creatine kinase. Chemiluminescence, an indicator of the in vitro production of peroxynitrite via the in vivo release of superoxide and nitric oxide, was also significantly attenuated by acetaminophen. Electron microscopy indicated a well-preserved myofibrillar ultrastructure in the postischemic myocardium of acetaminophen-treated hearts relative to vehicle-treated hearts (e.g., few signs of contraction bands, little or no evidence of swollen mitochondria, and well-defined light and dark bands in sarcomeres with acetaminophen; opposite with vehicle). We conclude that chronic administration of acetaminophen provides cardioprotection to the postischemic, reperfused rodent myocardium.

Effect of speed of development on mRNA expression pattern in early bovine embryos cultured in vivo or in vitro

2004 ◽  
Vol 68 (4) ◽  
pp. 441-448 ◽  
Author(s):  
A. Gutiérrez-ad´n ◽  
D. Rizos ◽  
T. Fair ◽  
P.N. Moreira ◽  
B. Pintado ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Expression Pattern ◽  
Bovine Embryos ◽  
Mrna Expression Pattern

scholarly journals Use of Melatonin in the In Vitro Production of Bovine Embryos

2020 ◽  
Vol 21 ◽  
Author(s):  
Alan da Silva LIRA ◽  
Ricardo de Macedo CHAVES ◽  
Felipe de Jesus MORAES JUNIOR ◽  
Sergio Henrique COSTA JUNIOR ◽  
Brenda Karine Lima do AMARAL ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
In Vitro Maturation ◽  
Control Group ◽  
Bovine Embryos ◽  
In Vitro Production ◽  
Maturation Medium ◽  
Significant Difference ◽  
Maturation Rate ◽  
Vitro Production

ABSTRACT We aimed to assess the effects of melatonin in the in vitro production of bovine embryos. Our experiment was conducted at the Laboratório de Reprodução Animal of the Universidade Estadual do Maranhão. The cumulus-oocyte complexes (COCs) were distributed among treatments at concentrations of 0, 10-1, 10-3 and 10-5 µMol/L melatonin. Our experiment was further divided into two: the first was to assess the effect of different concentrations of melatonin (treatments) on the maturation rate of COCs, and the second was to assess the effects of melatonin treatments on the in vitro production of bovine embryos. The results from the first experiment demonstrated no significant difference between the in vitro maturation rate of the cultivated COCs in treatments with melatonin. In the second experiment, however, melatonin treatments yielded statistically higher cleavage, morula and blastocyst rates in the 10-5 µM group (52.9%, 52.9%, and 35.3%, respectively), and lower rates in the 10-1 µM group (19.5%, 19.5% and 7.8%, respectively), compared to the others. The control group (no melatonin) and the 10-3 µM group showed similar results. We concluded that supplementation of melatonin in the in vitro maturation medium resulted in no improvement in the oocyte maturation rate, but in the in vitro production of embryos at different concentrations, the 10-5 µM group displayed better results, but with no improvement in the variables (P < 0.05).

191 IN VITRO CULTURE DURING OOCYTE MATURATION AND FERTILIZATION INFLUENCES THE TRANSCRIPTOME PROFILES OF BOVINE BLASTOCYSTS

2015 ◽  
Vol 27 (1) ◽  
pp. 186
Author(s):  
A. Gad ◽  
U. Besenfelder ◽  
V. Havlicek ◽  
M. Hölker ◽  
F. Rings ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Oocyte Maturation ◽  
Microarray Data ◽  
In Vitro Maturation ◽  
Culture Conditions ◽  
Control Group ◽  
Bovine Embryos ◽  
Vitro Fertilization

Early embryonic development, the period from oocyte maturation until blastocyst formation, is the most critical period of mammalian development. It is well known that in vitro maturation, fertilization, and culture of bovine embryos is highly affected by culture conditions. However, the stage-specific effect of culture environment is poorly understood. Therefore, we aimed to examine the effect of in vitro culture conditions during oocyte maturation and fertilization on the transcriptome profile of the resulting blastocysts. Bovine oocytes were matured in vitro and then either directly transferred to synchronized recipients, fertilized, and cultured in vivo (Vitro_M), or transferred after in vitro fertilization (Vitro_F), or at zygote stage (Vitro_Z) and blastocysts were collected at Day 7 by uterine flushing. For in vivo or in vitro fertilization, the same frozen-thawed commercial bull semen has been used. Complete in vitro (IVP) and in vivo produced blastocysts were used as controls. Gene expression patterns between each blastocyst group and in vivo produced blastocyst group were compared using EmbryoGENE's bovine microarray (EmbryoGENE, Québec, QC, Canada) over six replicates of each group (10 blastocyst/replicate). Microarray data were statistically analysed using the Linear Models for Microarray Data Analysis (LIMMA) package under the R program (The R Project for Statistical Computing, Vienna, Austria). Results showed that, the longer the embryos spent under in vitro conditions, the higher was the number of differentially expressed genes (DEG, fold-change = 2 with adjusted P-value = 0.05) compared with in vivo control group. The Vitro_M group showed the lowest number of DEG (149); in contrast IVP group represented 841, DEG, respectively compared to in vivo control group. Ontological classification of DEG showed that lipid metabolism was the most significant function influenced by in vitro maturation conditions. More than 55% of DEG in the Vitro_M group were involved in the lipid metabolism process and most of them showed down-regulation compared to in vivo control group. On the other hand, Vitro_F and Vitro_Z groups showed nearly similar numbers of DEG (584 and 532, respectively) and the majority of these genes in both groups were involved in cell-death- and cell-cycle-related functions. Pathway analysis revealed that retinoic acid receptor activation pathways were the common ones in the Vitro_M and Vitro_F groups. However, different signalling pathways were commonly dominant in the Vitro_F and Vitro_Z groups. This study provides the transcriptome elasticity of bovine embryos exposed to different environments during maturation, fertilization, and culture periods of development.

123 EFFECTS OF TAURO URSODEOXYCHOLIC ACID ON DEVELOPMENT OF BOVINE EMBRYOS FROM IN VITRO FERTILIZATION

2015 ◽  
Vol 27 (1) ◽  
pp. 153 ◽  
Author(s):  
F. Lu ◽  
Z. Li ◽  
Z. Ruan ◽  
X. Liu ◽  
S. Du ◽  
...  
Keyword(s):  
Mrna Expression ◽  
Fetal Bovine Serum ◽  
Cell Number ◽  
Control Group ◽  
Bovine Embryos ◽  
Total Cell Number ◽  
Qrt Pcr ◽  
Apoptosis Index ◽  
Fetal Bovine

Endoplasmic reticulum stress (ERS) is a novel apoptotic pathway and plays an important role for embryonic development. Tauro ursodeoxycholic acid (TUDCA) is a specific chemical chaperone that can inhibit ERS. In this study, we investigated the effects of TUDCA on the development and mRNA expression of ERS-related genes in bovine embryos from IVF in order to improve the efficiency of embryo in vitro culture. Bovine oocytes collected from ovaries at slaughter were cultured in the maturation medium (TCM-199 + 26.2 mmol L–1 NaHCO3 + 5 mmol L–1 HEPES + 5% fetal bovine serum) for 24 h and fertilized in vitro with bovine sperm. After fertilization, the embryos were respectively placed into the medium (TCM-199 + 3% fetal bovine serum) containing different concentrations of TUDCA (0, 100, 250, 500, 1000 μmol L–1) and cultured in the 5% CO2 at 38.5°C. Blastocyst development was evaluated after 7 days of culture, and then the total cell number and apoptosis index of blastocysts were detected with TUNEL. In addition, X-box binding protein 1 (XBP-1) of embryos at 2-cell, 4-cell, morula, and blastocyst stages was detected with RT-PCR, and the change of the mRNA expression of ERS-related (Grp78, Ire1, Chop) and apoptosis-related (Bax, Bcl-2) genes in blastocyst collected at 7 days of culture were analysed by QRT-PCR. A total of 1336 oocytes were used in this study, and each experimental group comprised 6 replicates. The results revealed that the splicing of XBP-1 was present during the development of bovine embryos, and especially obvious at the 4-cell, morula, and blastocyst stages. When embryos were cultured in medium with different concentrations of TUDCA, compared with the control group (0 μmol L–1), more embryos developed to blastocyst stage with 500 μmol L–1 TUDCA (31.86 ± 7.32% v. 21.11 ± 8.05%; P < 0.05), but the cleavage rate was not significantly different among groups (P > 0.05). The result for TUNEL found that when adding 500 μmol L–1 TUDCA to culture, the bovine embryos significantly improved the total cell number of blastocysts (110. ± 15.21 v. 102.3 ± 8.62; P < 0.05), and the apoptosis index of blastocysts was markedly decreased (3.71 ± 0.91 v. 5.36 ± 1.92; P < 0.05) relative to the control group. Moreover, the result of QRT-PCR analysis showed that treating embryos with 500 μmol L–1 TUDCA significantly reduced the mRNA expression level of Ire1 and Chop genes (P < 0.05) and up-regulated the expression of anti-apoptotic Bcl-2 gene (P < 0.05), while down-regulated the expression of pro-apoptotic Bax gene (P < 0.05). Furthermore, XBP-1 splicing in blastocysts also abated after embryos were treated with 500 μmol L–1 TUDCA. In conclusion, ERS occurs in bovine embryos during in vitro culture, but treating embryos with 500 μmol L–1 TUDCA may reduce ERS to facilitate embryonic development. This work was funded by the China High Technology Development Program (2011AA100607), China Natural Science Foundation (31072033), and Guangxi Science Foundation (2011GXNSFA018084, 2012GXNSFFA060004).

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