280 EXPRESSION OF HSP70.1 GENE IN IN VITRO-PRODUCED BOVINE EMBRYOS CULTURED IN CR2 MEDIUM SUPPLEMENTED WITH KNOCKOUT™SR

2007 ◽  
Vol 19 (1) ◽  
pp. 255
Author(s):  
R. V. Serapião ◽  
L. S. de Almeida Camargo ◽  
A. de Almeida Ramos ◽  
I. de Moura Folhadella ◽  
J. Polisseni ◽  
...  

The exposure of embryos to serum during in vitro culture can affect morphology, metabolism, tolerance to cryopreservation, and expression of specific transcripts. On the other hand, serum-free medium seems to avoid some of those serum effects. KnockoutTMSR (GIBCO Laboratories, Grand Island, NY, USA) is a serum replacer optimized to support embryonic stem cells in culture and can also be used to replace serum during culture of in vitro-fertilized bovine embryos. The expression of genes associated with stress response, such as heat shock proteins (HSP), can be affected by in vitro culture conditions, being easily induced by a variety of stress agents, including culture medium components. This study aimed to determine whether KnockoutSR or serum in culture medium alters the relative abundance of HSP70.1 transcripts in in vitro-fertilized bovine embryos. Cumulus–oocyte complexes obtained from slaughterhouse ovaries were matured and feritlized in vitro. Presumptive zygotes were randomly cultured with their own cumulus cells in CR2aa medium supplemented with 10% fetal calf serum (GIBCO-BRL, Paisley, UK; FCS group), 10% KnockoutSR (GIBCO-BRL; KSR group), or 3 mg mL-1 of polyvinyl alcohol (PVA group). All steps were performed at 38.5�C, under 5% CO2 in air and 95% humidity. Blastocysts on Day 8 post-fertilization were rapidly frozen in liquid nitrogen and subsequently thawed for RNA extraction (3 replicates for each group). Total RNA extraction was performed using an Rneasy� Micro kit (Qiagen, Valencia, CA, USA), and the first strand was synthesized using SuperscriptTM III First Strand Synthesis kit (Invitrogen, Chicago, IL, USA). Relative quantification was performed in duplicate using real-time PCR (ABI Prism� 7000 Applied Biosystems, Foster City, CA, USA); reactions consisted of a mixture of iTaqTM SYBR� Green Supermix with ROX (Bio-Rad, Waltham, MA, USA) with cDNA equivalent to 0.8 embryos and gene-specific primers. Expression of the glyceraldehyde 3-phosphate dehydrogenase gene was used as endogenous reference. Calculations of relative quantification were performed by comparative Ct method, using the value found in the PVA group as calibrator. Expression levels for the FCS and KSR groups were 1.2 � 0.06- and 1.4 � 0.08-fold differences relative to the PVA group without differences (P > 0.05). These data show that bovine embryos cultured in medium supplemented with KSR have the same HSP70-1 expression pattern as those in medium with added FCS, suggesting that embryos in both groups are under the same stress conditions. This work was supported by FAPEMIG, MG, Brazil, and CNPq, DF, Brazil. Thanks to Agrogenetica, Vi�osa, Brazil, for the real-time PCR machine.

2007 ◽  
Vol 19 (1) ◽  
pp. 247
Author(s):  
L. S. A. Camargo ◽  
J. H. M Viana ◽  
R.V. Serapião ◽  
M. F. M. Guimarães ◽  
W. F. Sá ◽  
...  

Heat stress is one of the main causes of low conception rate in Bos taurus cows in a tropical climate. On the other hand, in this environment, oocytes from Bos indicus show greater developmental capacity after in vitro fertilization than those from Bos taurus, suggesting an adaptation to the hot climate. Heat shock proteins (HSP) are chaperones that promote protection against heat damage, and their transcription is associated to stress. The aim of this study was to evaluate the expression of HSP70-1 gene (Genbank NM174550), a member of HSP family, in oocytes from Bos taurus (Holstein) and Bos indicus (Gyr) cows raised in the tropical climate located at 21�35′′S latitude, 43�51′′W longitude, and 435 m altitude. Cumulus–oocyte complexes were recovered by oocyte pickup from mature non-lactating Holstein (n = 4) and Gyr (n = 4) donor cows during the hot season. Cumulus cells of viable oocytes were removed by vortexing in TALP-HEPES plus BSA, and pools (3 for each breed) with 12 immature oocytes were rapidly frozen in liquid nitrogen and subsequently thawed for RNA extraction. Total RNA extraction was performed using Rneasy� Micro kit (Qiagen, Valencia, CA, USA), and first strands were synthesized using SuperscriptTM III First Strand Synthesis kit (Invitrogen, Chicago, IL, USA). Relative quantification was performed in duplicate using real-time PCR (ABI Prism� 7000; Applied Biosystems, Foster City, CA, USA); reactions consisted of a mixture of iTaqTM SYBR� Green Supermix with ROX (Bio-Rad, Waltham, MA, USA) and cDNA equivalent to 1.2 oocytes and gene specific primers. Expression of the GAPDH gene was used as endogenous reference. Calculations of relative quantification were performed by the comparative Ct method, using the lowest value found in Bos indicus oocytes as calibrator; values (mean � SE) are shown as n-fold difference relative to the calibrator. Statistical comparison between breeds was performed by analysis of variance. Oocytes from Holstein cows showed a higher level (P < 0.05) of HSP70-1 expression (1.82 � 0.22) than oocytes recovered from Gyr cows (1.12 � 0.11). Previous study reported that oocytes from Gyr cows in a tropical climate showed a higher blastocyst rate after in vitro fertilization than Holstein oocytes (Camargo et al. 2006 Reprod. Fertil. Dev. 18, 243 abst). The lower level of HSP70-1 in Gyr oocytes suggests that they were less subject to stress than the Holstein ones, which may reflect their capacity to develop after fertilization. This effect may be, at least in part, due to the ability of Bos indicus cows to regulate body temperature in a hot environment, causing less stress on oocytes. Financial support was provided by FAPEMIG, MG, Brazil, and CNPq, DF, Brazil. Thanks to Agrogen�tica, Vi�osa, Brazil, for the real-time PCR machine.


2007 ◽  
Vol 19 (1) ◽  
pp. 120 ◽  
Author(s):  
M. P. Milazzotto ◽  
W. B. Feitosa ◽  
B. E. Strauss ◽  
M. Bajgelman ◽  
C. M. Mendes ◽  
...  

The main goal of husbandry and beef cattle production is to enhance performance rates, for example, weight gain. Myostatin is referred to as a negative regulator of skeletal muscle growth. Genetic engineering of this character in order to produce double muscling animals that can transmit to future progeny will enhance its usefulness. The present research aimed to analyze myostatin inhibition through lentiviral-mediated delivery of shRNA in mouse myoblast culture and the feasibility of the lentiviral-mediated delivery of shRNA into in vitro-produced transgenic bovine embryos. In order to achieve knockdown of myostatin in cell and embryo culture, a lentiviral vector was constructed with ubiquitin C promoter-driven GFP gene (green fluorescent protein) and shRNA to suppress myostatin gene expression driven by the U6 promoter. Vector efficiency was verified through in vitro murine myoblast (C2C12) cell morphology after inductive differentiation and by means of real-time PCR of myostatin and GAPDH genes. Later, bovine oocytes were in vitro-matured and the lentiviral vector was microinjected into the oocyte perivitelline space (2.5 � 106 IU mL-1) after mechanical and chemical cumulus cell removal. Non-microinjected mature oocytes were considered as control. After microinjection, oocytes were fertilized and cultured in vitro. After 4 and 9 days of culture, embryos were evaluated by epifluorescence microscopy. The GFP-positive embryos were green under fluorescence. Cell morphology and embryo development rate data were analyzed by Minitab Release 14 Statistical Software (Minitab, Inc., State College, PA, USA), submitted to ANOVA, and compared by Tukey test (P d 0.05). Real-time PCR data were analyzed by Pair-Wise Fixed Reallocation Randomization Test using REST2005 software. Cell morphology results demonstrated that the vector was able to inhibit myostatin mRNA in C2C12 cells as the transducted group progressed less to myotubes than in the control group. A lower amount of myostatin mRNA after 72 h of differentiation indicated an inhibition tendency by real-time PCR. In relation to the transgenic embryo production, 96.9 � 0.34% (62.65) developed to cleavage, 80.24 � 4.38% (51/65) were GFP-positive, and 50.95 � 3.37% (26/65) achieved blastocyst stage. After hatching, 3.07% (2/65) of GFP-positive embryos maintained fluorescence. In relation to the control group, the cleavage rate was 93.81 � 0.68% (61/65); the blastocyst rate 38.34 � 2.36% (25/65), and none were fluorescent. In conclusion, myostatin gene knockdown was effectively performed by lentiviral vector-mediated delivery of shRNA. Thus, novel studies about the efficiency of this vector on transgenic embryo production can be performed. This work was supported financially by FAPESP 03/0156-9.


Zygote ◽  
2012 ◽  
Vol 22 (2) ◽  
pp. 146-157 ◽  
Author(s):  
Daniela Martins Paschoal ◽  
Mateus José Sudano ◽  
Midyan Daroz Guastali ◽  
Rosiára Rosária Dias Maziero ◽  
Letícia Ferrari Crocomo ◽  
...  

SummaryThe objective of this study was to assess the viability and cryotolerance of zebu embryos produced in vitro with or without the addition of fetal calf serum (FCS) and forskolin (F). Embryos produced in vivo were used as a control. Presumptive zygotes were cultured in modified synthetic oviductal fluid supplemented with amino acids (SOFaa), bovine serum albumin (BSA) and with (2.5%) or without (0%) FCS. On day 6 of growth, the embryos from each group were divided into treatments with or without 10 μM F to induce embryonic lipolysis, comprising a total of four experimental groups: 2.5% FCS, 0% FCS, 2.5% + F and 0% + F. For vitrification, embryos were exposed to vitrification solution 1 (5 M EG (ethylene glycol)) for 3 min and then transferred to vitrification solution 2 (7 M EG, 0.5 M galactose solution and 18% (w/v) Ficoll 70) before being introduced to liquid nitrogen. The presence of FCS in the culture medium resulted in the production of embryos with a similar rate of damaged cells compared with in vivo-produced embryos. After vitrification, the 2.5% FCS group had a significantly higher rate of damaged cells when compared with the other groups (P < 0.05). The results of this experiment indicated that the omission of FCS and the addition of forskolin do not have deleterious effect on embryo production rates. In addition, embryos produced in the presence of FCS had greater sensitivity to cryopreservation, but this effect was reversed when forskolin was added to the medium, which improved embryo survival without affecting embryo development and quality after vitrification.


2017 ◽  
Vol 29 (3) ◽  
pp. 621 ◽  
Author(s):  
Ricaurte Lopera-Vasquez ◽  
Meriem Hamdi ◽  
Veronica Maillo ◽  
Valeriano Lloreda ◽  
Pilar Coy ◽  
...  

To evaluate the effect of bovine oviductal fluid (OF) supplementation during in vitro culture of bovine embryos on their development and quality, in vitro-produced zygotes were cultured in synthetic oviductal fluid (SOF; negative control; C–) supplemented with OF or 5% fetal calf serum (positive control; C+). Embryo development was recorded on Days 7–9 after insemination and blastocyst quality was assessed through cryotolerance, differential cell counting of the inner cell mass and trophectoderm, and gene expression. OF was added to the culture medium at concentrations ranging from 0.625% to 25%. The higher OF concentrations (5%, 10% and 25%) had a detrimental effect on embryo development. Lower OF concentrations (1.25% and 0.625%) supported embryo development until Day 9 (27.5%) and produced higher-quality blastocysts, as reflected by their cryotolerance (53.6% and 57.7% survival at 72 h, respectively, vs 25.9% in C+) and total cell number (mean (± s.e.m.) 165.1 ± 4.7 and 156.2 ± 4.2, respectively, vs 127.7 ± 4.9 in C– and 143.1 ± 4.9 in C+). Consistent with these data, upregulation of the water channel aquaporin 3 (AQP3) mRNA was observed in blastocysts supplemented with 1.25% OF compared with C– and C+. Serum supplementation resulted in a reduction in the expression of glucose and lipid metabolism-related genes and downregulation of the epigenetic-related genes DNA methyltransferase 3A (DNMT3A) and insulin-like growth factor 2 receptor (IGF2R). In conclusion, in vitro culture with low concentrations of OF has a positive effect on the development and quality of bovine embryos.


2007 ◽  
Vol 19 (1) ◽  
pp. 229
Author(s):  
M. L. Lim ◽  
I. Vassiliev ◽  
P. J. Verma

Teratoma formation is commonly used as a model for examining the in vivo differentiation potential of embryonic stem cells. We wanted to investigate the teratoma-forming ability of bovine ES cells; however, there are no reports of teratoma-forming ability of bovine pluripotent cells including pre-implantation embryos. In vivo-produced bovine embryos at stages earlier than Day 14 failed to develop teratomas when transplanted into one of the kidneys of immuno-deficient mice (Anderson et al. 1996 Anim. Reprod. Sci. 45, 231–240), and this prompted questions about the ability of bovine embryos to form teratomas. Bovine oocytes were cultured for 20 to 22 h after aspiration at 39�C (5% CO2/95% air) in TCM-199-bicarbonate medium supplemented with GlutaMax6" (Invitrogen Australia Pty Ltd., Mount Waverley, Victoria, Australia), penicillin/streptomycin, β-mercaptoethanol, 17β-estradiol, fetal calf serum, LH, follicle stimulating hormone, basic fibroblast growth factor, epidermal growth factor, glycine, and l-cysteine. Oocytes were fertilized with IVF media (Cook Australia, Brisbane, Queensland, Australia) and kept for 7 days at 39�C in 5% CO2/95% air to generate blastocysts. The zona pellucida of Day 7 blastocysts was enzymatically removed, and one or two zona-free embryos were injected into each testis of 5-week-old immunodeficient (SCID) mice (CB-17/ICR-Prkdcscid strain; Walter and Eliza Hall Institute, Melbourne, Australia). Eight weeks post-injection, teratomas partially expelled from testes were identified. Histological analysis has confirmed the derivatives of all 3 germ layers in teratomas. In conclusion, we report that Day 7 in vitro-produced embryos can form teratomas when injected into testes of SCID mice.


2011 ◽  
Vol 23 (1) ◽  
pp. 173
Author(s):  
M. J. Sudano ◽  
D. M. Paschoal ◽  
T. S. Rascado ◽  
L. C. O. Magalhães ◽  
L. F. Crocomo ◽  
...  

Phenazine ethosulfate (PES) is a metabolic regulator that inhibits fatty acid synthesis and favours the pentose-phosphate pathway. Supplementation of fetal calf serum (FCS) during culture has been correlated with the reduction of quality of in vitro produced bovine embryos (IVPE). The aim of the present study was to evaluate embryo development and apoptosis in blastocysts after the supplementation of PES and FCS in culture medium of IVPE. Oocytes (N = 4320) were matured and fertilized in vitro (Day 0). The zygotes (Bos indicus) were cultured in SOFaa medium with 4 concentrations of FCS (0, 2.5, 5, and 10%) and with the use or not of 0.3 μM PES from Day 4 (after 96 h of embryo culture). Embryo development was evaluated after 7 days of culture. Apoptosis in blastocysts (N = 60–80) was accessed through TUNEL reaction. Embryos (Bos indicus) recovered from superstimulated cows were used as in vivo control (n = 15). Data were analysed by ANOVA followed by LSD using PROC GLIMMIX (SAS; SAS Institute Inc., Cary, NC, USA) means ± SEM. Increasing FCS concentration in the culture media did not change cleavage (86.7 ± 1.7, 82.3 ± 1.6, 86.3 ± 1.4, 87.0 ± 1.5, P > 0.05) and augmented blastocyst production (30.5 ± 2.5a, 41.8 ± 2.4b, 40.5 ± 2.6b, 47.2 ± 2.8b, P < 0.05), respectively, for 0, 2.5, 5, and 10%. Additionally, increasing FCS concentration increased apoptosis in blastocysts (13.8 ± 1.2b, 19.1 ± 1.8b, 20.7 ± 1.9bc, 28.4 ± 2.3c, P < 0.05, respectively, for 0, 2.5, 5, and 10%). The addition of PES from Day 4 in the culture medium did not affect (P > 0.05) cleavage (87.0 ± 1.3 and 84.4 ± 1.3), blastocyst production (42.0 ± 2.8 and 43.0 ± 2.0), and apoptosis in blastocysts (20.7 ± 2.0b and 18.9 ± 2.1b), respectively, for control and PES Day 4 groups. Independent of FCS withdrawal or PES addition to culture medium, the in vivo control group presented the lowest apoptosis rate (6.3 ± 1.1a). Therefore, increasing FCS concentration augmented embryo development and reduced blastocyst quality. However, the addition of 2.5% of FCS in the culture medium increased the embryo development without the reduction of blastocyst quality. Moreover, the PES supplementation from Day 4 did not affect embryo development and blastocyst quality. São Paulo Research Foundation – FAPESP.


2012 ◽  
Vol 24 (1) ◽  
pp. 196
Author(s):  
A. R. Buzzo ◽  
A. R. Pupulim ◽  
J. Mazucheli ◽  
F. V. Meirelles ◽  
I. P. Emanuelli

Approaches to improve the culture medium for in vitro production (IVP) of bovine embryos have been continuous because of the high commercial demand and a portion of this attempts the production of female cattle (dairy cows and stud cattle). However, in some embryonic in vitro culture systems, the development kinetics is faster in male than in female embryos (Avery 1992 Mol. Reprod. Dev. 32, 265–70; Xu 1992 Mol. Reprod. Dev. 31, 249–50). The aim of this work was to relate the kinetics of blastocyst expansion with the production rates of male and female embryos. Cumulus–oocyte complexes (n = 917; classes I and II) of cows from a slaughterhouse were matured with TCM-199 bicarbonate and 10% FCS (38.5°C, 5% CO2) for 24 h and fertilized with frozen-thawed semen in TALP-IVF medium for 18 h. Presumptive zygotes were culture in SOF medium supplemented with 10% FSB (5% O2, 38.5°C). Seven days after IVF, embryos were divided in 2 groups according to their kinetic stage of development: nonexpanded blastocysts (n = 175), or hatched and expanded blastocysts (n = 146). Hence, embryos were individually frozen in LN and stored in cryotubes. After thawing, Proteinase K (16 mg mL–1) was added to each tube and the tubes were incubated for 60 min at 37°C. Proteinase was denatured at 98°C for 10 min and the contents of each tube were divided into 2 samples (A and B) and subjected to the PCR technique. Two pairs of primers for the specific sequence of the Y chromosome were used to amplify the sequence of 210 and 250 bp for the male bovine and 1 pair of primers was used for the autosomal bovine sequence with a 280-bp fragment. Female embryos with a 280-bp product were observed in sample A and none were observed in sample B. The presence of 2 amplicons (280 and 210 bp) in sample A and 1 amplicon of 250 bp in sample B indicated that the embryo was male. A chi-square test was used to evaluate homogeneity. An analysis of the percentage of males and females between the experimental groups was performed by logistic regression and significance was considered when P < 0.05. There was no difference in the proportions of males and females in the nonexpanded blastocyst group (49.71 and 50.29%; P > 0.05). In the hatched and expanded blastocyst group, the proportion of males (65.75%) was statistically different from the proportion of females (34.25%); that is, the chance of the embryo being male was twice as high (P < 0.0038). These results suggest that there is a difference in the kinetics of embryo development between male and female embryos and that blastocyst expansion can point that out. In vitro culture media with FCS support the development of expanded male blastocysts. Further research in culture medium modifications (FCS, the energy source, amino acids and others) are needed to respond to the trend in the production of sex-defined embryos.


2007 ◽  
Vol 19 (1) ◽  
pp. 258
Author(s):  
E. Warzych ◽  
E. Pers ◽  
A. Buszka ◽  
T. Strabel ◽  
D. Lechniak

The efficiency of in vitro embryo production in cattle varies between 30 and 40% of blastocysts derived from oocytes matured in vitro. Despite a rigorous selection, some embryos at blastocyst stage displaying normal morphology are not competent to develop after hatching (Maddox-Hyttel et al. 2003 Reproduction (Suppl. 61), 103–116). Therefore, a lot of attention has been focused on embryo quality. Supplements to culture media are one of the factors significantly contributing to this phenomenon. Serum (FBS) and albumin (fatty acid-free BSA, fafBSA) are widely used protein supplements; however, their effect on embryo quality is still variable (Rizos et al. 2003 Biol. Reprod. 68, 236–243). The aim of the present study was to investigate whether good-quality blastocysts (hatched or expanded) derived from oocytes matured in media supplemented with FBS or fafBSA differ in transcript level of 2 genes: heat shock protein (Hsp70) and receptor for insulin-like 2 factor (IGF2R). Bovine Day 8 blastocysts were produced in vitro from oocytes aspirated from slaughterhouse ovaries after maturation in TCM-199 medium supplemented with 10% FBS or 6% fafBSA, as previously described (Makarevich and Markkula 2002 Biol. Reprod. 66, 386–392). On Day 8 post-insemination (pi), good-morphology blastocysts were allocated into 3 groups: (1) hatched, (2) expanded of excellent quality, and (3) expanded of good quality, and individually frozen in liquid nitrogen. Each embryo was processed individually through RNA extraction and cDNA synthesis. Transcript quantitation protocol included: real-time PCR with SYBR Green I, β-actin gene as an internal standard, and relative standard curve method. Data analysis was performed by 2-way ANOVA. In each reaction, an equivalent of 0.125 embryo (2.5 �L of cDNA) was used, and 43 blastocysts were analyzed. All analyzed embryos were positive for the Hsp70 transcript, whereas IGF2R mRNA was detected in only 58% of blastocysts regardless of the maturation medium. A large variation in relative abundance (RA) was observed among individual embryos: coefficients of variation were 114.5 and 323.6% for IGF2R and Hsp70, respectively. Due to the distribution of Hsp70 RA, log transformation was performed. Real-time PCR data revealed a maximum 100-fold variation for the reference gene. Hatched blastocysts were characterized by a significantly lower RA for both analyzed genes. The 2 classes of expanded blastocysts did not differ in transcript level. With regard to protein supplements, only the RA for Hsp70 gene was significantly affected. This transcript was more abundant in embryos derived from fafBSA-supplemented IVM medium. The present results confirmed previously the described phenomenon concerning a large variability in mRNA content in single pre-implantation embryos. Moreover, because embryos able to hatch significantly differed in RA from their expanded counterparts, it is possible to relate embryo quality to transcript level.


2012 ◽  
Vol 24 (1) ◽  
pp. 194
Author(s):  
S. Miyashita ◽  
Y. Inaba ◽  
T. Somfai ◽  
M. Geshi ◽  
T. Nagai ◽  
...  

The objective of this study was to investigate the effects of the supplementation of a lipid metabolism inducer, L-carnitine (LC) and a membrane stabilizer, linoleic acid albumin (LAA), on the developmental competence and cryosurvival of bovine in vitro-matured/in vitro-fertilized embryos in in vitro culture medium. Cumulus–oocyte complexes collected from the ovaries of slaughtered cattle were matured for 20 h in TCM-199 supplemented with 5% calf serum (CS) and 0.02 AU mL–1 of FSH at 38.5°C in an atmosphere of 5% CO2 in air. After IVF (Day 0), presumptive zygotes were cultured in CRlaa containing 5% CS at 38.5°C in an atmosphere of 5% CO2, 5% O2 and 90% N2 for 9 days. The culture medium was supplemented with 0.6 mg mL–1 of LC (LC group; n = 180) or with 0.25 mg mL–1 of LAA (LAA group; n = 180) or with both LC and LAA (LC + LAA group; n = 180) or without LC and LAA (control; n = 178). The cleavage rates were recorded on Day 2 and the blastocyst formation rates were recorded on Day 7 to 9. Expanded blastocysts harvested on Day 7 and 8 (LAA group: n = 31; LC group: n = 29; LC + LAA group: n = 25; control group: n = 33) were used for freezing in modified PBS supplemented with 1.5 M ethylene glycol, 0.1 M sucrose and 20% CS. After thawing, they were cultured in TCM-199 supplemented with 20% FBS and 0.1 mM β-mercaptoethanol at 38.5°C under 5% CO2 in air for 72 h. The rates of re-expansion, hatching and formation of hatched blastocysts were determined at 24, 48 and 72 h after thawing, respectively. The rates of cleavage and blastocyst formation were expressed as mean ± s.e.m. and analysed by ANOVA. The post-thaw survival rates of frozen embryos were analysed by chi-square test. The cleavage rate in the control group (69.1 ± 2.5%) was significantly lower than that in the LAA (81.8 ± 3.8%) and LC + LAA groups (77.9 ± 1.4%) but did not differ from that in the LC group (73.8 ± 2.4%). The blastocyst formation rate in the control group (21.7 ± 2.8%) was significantly lower (P < 0.05) than those in the LAA and LC + LAA groups (33.5 ± 2.8% and 31.4 ± 2.4%, respectively), but it did not differ significantly from that of the LC group (32.1 ± 3.3%) despite a strong tendency (P = 0.06). There were no significant differences among the control, LC, LAA and the LC + LAA groups in post-thaw re-expansion rates (66.7, 75.9, 67.7 and 76.0%, respectively), hatching rates (48.5, 69.0, 58.1 and 64.0%, respectively) and rates of formation of hatched blastocysts (51.5, 62.1, 61.3 and 64.0%, respectively). These results indicate that the addition of LC and LAA to the medium for in vitro culture of in vitro-matured/in vitro-fertilized bovine embryos improved their ability to develop to the blastocyst stage; however, the effects on the freezing tolerance were not verified.


2010 ◽  
Vol 22 (1) ◽  
pp. 284
Author(s):  
K. Smits ◽  
K. Goossens ◽  
A. Van Soom ◽  
L. Peelman

Although in vitro production of equine embryos has greatly evolved in recent years, there are still substantial differences between in vitro-produced and in vivo-derived equine embryos. Fundamental insight into these differences could lead to optimization of equine assisted reproductive techniques. Reverse transcription quantitative real-time PCR (RT-qPCR) is a highly specific and sensitive tool to compare mRNA expression levels of specific genes and was used in this study to determine differences in gene expression between equine in vivo and in vitro embryos. In vivo embryos (n = 8) were derived by uterine flushing of artificially inseminated mares at 7 days after ovulation. For the production of the in vitro embryos (n = 8), oocytes from slaughtered mares were matured in DMEM-F12-based medium (Galli et al. 2007 Anim. Reprod. Sci. 98, 39-55) in 5% CO2 in air (maturation rate: 57%), fertilized by intracytoplasmic sperm injection, and cultured in DMEM-F12 with 10% fetal calf serum in 5% CO2, 5% O2, and 90% N2 for 9.5 days (cleavage rate: 74%; blastocyst rate: 7%). RNA was extracted from single early to expanded blastocysts and amplified and converted into cDNA with the WT-Ovation RNA Amplification System (NuGEN, San Carlos, CA, USA). Based on the presumed gene functions and differential gene expression as determined in a previously performed suppression subtractive hybridization (SSH; Smits et al. 2009 Reprod. Dom. Anim. 44, 75), 5 genes [brain expressed X-linked 2 (BEX2), Mps one binder kinase activator-like 3 (MOBKL3), fatty acid binding protein 3 (FABP3), minichromosome maintenance complex component 7 (MCM7), and ornithine decarboxylase (ODC)] were selected for quantification by RT-qPCR with the KAPA SYBR® FAST qPCR Kit (Kapa Biosystems, Belgium) on the iCycler iQ Real-Time PCR Detection System (Bio-Rad, Nazareth, Belgium). All data were normalized with previously determined stable reference genes (beta actin, ubiquitin C, ribosomal protein L32, and glyceraldehyde-3-phosphate dehydrogenase) and statistically analyzed by means of a Mann-Whitney test. The fact that all genes were expressed at greater levels in the in vivo-derived blastocysts than in the in vitro-produced blastocysts confirmed the results of the SSH. This difference was highly significant for MOBKL3, BEX2, and ODC (P < 0.005), significant for FABP3 (P < 0.05), and not significant for MCM7. These genes have already been shown to be important for embryonic cell survival (ODC), oocyte maturation and pre- implantation development (MOBKL3) in mice, regulation during embryonic development (BEX2) and fetal development (FABP3) in human, and genome replication in eukaryotes (MCM7) (Pendeville et al. 2001 Mol. Cell Biol. 21, 6549-6558; Han et al. 2005 Nucleic Acids Res. 33, 6555-6565). In conclusion, 4 genes (MOBKL3, BEX2, ODC, and FABP3) with greater expression levels in in vivo-derived equine blastocysts have been identified. Whether the up-regulation of these genes is important for normal embryonic differentiation in the horse embryo is currently under investigation.


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