scholarly journals 80 GENE EXPRESSION PROFILES AND IN VITRO DEVELOPMENT FOLLOWING VITRIFICATION OF PRONUCLEAR AND 8 CELL-STAGE MOUSE EMBRYOS

2005 ◽  
Vol 17 (2) ◽  
pp. 190
Author(s):  
D. Boonkusol ◽  
A. Baji Gal ◽  
S.Z. Bodo ◽  
B. Gorhony ◽  
K. Pavasuthipaisit ◽  
...  

The analysis of differences in gene expression of embryos in response to cryopreservation may explain some of the observed differences in further development. Experiments were conducted to study effects of two vitrification methods, solid surface (SSV) and in-straw vitrification (STR), for pronuclear and 8 cell-stage mouse embryos with regard to gene expression and in vitro development. Both stages of embryos were vitrified by SSV (Dinnyes et al. 2000 Biol. Reprod. 63, 513–518) using 35% ethylene glycol (EG) for vitrification solution (VS) and STR using 40% EG for VS. Warming and rehydration of embryos in the SSV method was performed by placing vitrified droplets into a 37°C 0.3 M trehalose solution for 1 min, and then for 2 min in each of 0.15 M trehalose, 0.075 M trehalose, and base medium at room temperature before culture in CZB medium. Warming of embryos for the in-straw method was performed by holding straws in air for 10 s and then plunging them into 37°C water for 15–20 s. The contents of the straws were expelled into 37°C 0.3 M trehalose solution and embryos were treated as above. No significant differences were found between immediate survival rates of embryos vitrified by SSV and STR in both stages. Blastocyst rates were significantly higher with SSV than with STR and not significantly different from those of the control (Table 1). These results show that SSV was more efficient than STR. Quantification of selected gene transcripts from single embryo (6 embryos/treatment group) was carried out by quantitative real-time RT-PCR. Genes related to oxidative stress (MnSOD and CuSOD), cold stress (CIRP, RBM3, and p53), and β-actin as reference gene were amplified. We found up-regulation of all stress genes at 3 h post-warming in all treatment groups. At 10 h post-warming, a low level of gene expression was found in SSV-treated embryos, but gene expression remained at high level in STR-treated embryos. However, no differences in gene expression were found between blastocysts developed from fresh and vitrified embryos. In conclusion, the real-time RT-PCR method from single embryos opened new opportunities for understanding molecular events following cryopreservation. The continuous up-regulation of stress-related genes at 10 h post-warming might have been an early indicator of reduced viability following STR, as was also indicated by the developmental rate to the blastocyst stage. Table 1. Survival and blastocyst rates of vitrified/warmed pronuclear and 8 cell-stage mouse embryos This work was supported by the Thailand Research Fund (Royal Golden Jubilee Ph.D. scholarship) and a Bio-00017/2002 grant of the Hungarian National Office of Research and Technology.

2006 ◽  
Vol 73 (6) ◽  
pp. 700-708 ◽  
Author(s):  
Duangjai Boonkusol ◽  
Arpad Baji Gal ◽  
Szilard Bodo ◽  
Botond Gorhony ◽  
Yindee Kitiyanant ◽  
...  

2012 ◽  
Vol 24 (2) ◽  
pp. 370 ◽  
Author(s):  
Dorji ◽  
Yukihiro Ohkubo ◽  
Kazuchika Miyoshi ◽  
Mitsutoshi Yoshida

The present study was carried out to compare the gene expression profiles of in vitro-generated embryos derived from adult and prepubertal Japanese Black cattle oocytes using GeneChip Bovine Genome Array (containing 24 072 probe sets representing over 23 000 transcripts). Microarray experiments were performed on populations of 8- to 16-cell stage embryos and blastocysts derived from adult (24–35 months old) versus prepubertal (9–10 months old) Japanese Black cattle oocytes matured and fertilised in vitro. In total, 591 (2.4%) and 490 (2.0%) genes were differentially expressed in prepubertal and adult bovine in 8- to 16-cell and blastocyst stage embryos, respectively. Out of these, 218 and 248 genes were upregulated, while 373 and 242 were downregulated in prepubertal and adult 8- to 16-cell and blastocysts stage embryos, respectively. Gene ontology classification regarding biological process, molecular functions and cellular component revealed diversity in transcript abundances between prepubertal and adult groups in both the distinct developmental stages. Quantitative reverse transcription–PCR validated the expression differences of some selected transcripts as identified by microarray analysis. To our knowledge, this is the first report indicating the significant number of genes differentially expression (>2-fold, P < 0.01) in preimplantition embryos between adult and prepubertal Japanese Black cattle during in vitro development.


2008 ◽  
Vol 20 (1) ◽  
pp. 165
Author(s):  
X. S. Cui ◽  
X. Y. Li ◽  
T. Kim ◽  
N.-H. Kim

Trichostatin A (TSA) is an inhibitor of histone deacetylase and is able to alter gene expression patterns by interfering with the removal of acetyl groups from histones. The aim of this study was to determine the effect of TSA treatment on the development and gene expression patterns of mouse zygotes developing in vitro. The addition of 100 nm TSA to the culture medium did not affect the cleavage of mouse embryos (TSA treatment, 148/150 (99%) v. control, 107/107 (100%)); however, embryos that were treated with TSA arrested at the 2-cell stage (145/148, 98%). We estimated the number of nuclei in control and TSA-treated embryos by propidium iodide staining, taking into account the presence of any cells with two or more nuclei. At 62–63 h post-hCG stimulation, control zygotes had developed to the 4-cell stage and exhibited one nucleus in each blastomere, indicative of normal development. In contrast, we observed tetraploid nuclei in at least one blastomere in 20.8% (11/53) of the embryos that had been treated with TSA. At 28–29 h post-hCG stimulation (metaphase of the 1-cell stage), there was no difference in the mitotic index (as determined by analyzing the microtubule configuration) in the TSA group compared to the control group. At the 2-cell stage, however, we did not observe mitotic spindles and metaphase chromatin in embryos in the TSA treatment group compared to the controls. Interestingly, when embryos were cultured in TSA-free medium from 35 h post-hCG stimulation (S- or early G2-phase of the 2-cell stage) onward, almost all of them (47/50) developed to the blastocyst stage. In contrast, when embryos were cultured in TSA-free medium from 42 h post-hCG stimulation (middle G2-phase of the 2-cell stage) onward, they did not develop to the 4-cell stage. We used Illumina microarray technology to analyze the gene expression profiles in control and TSA-treated late 2-cell-stage embryos. Applied Biosystems Expression System software was used to extract assay signals and assay signal-to-noise ratio values from the microarray images. Our data showed that 897 genes were significantly (P < 0.05; 2-sample t-test) up- or down-regulated by TSA treatment compared to controls. Analysis using the PANTHER classification system (https://panther.appliedbiosystems.com) revealed that the 575 genes that were differentially expressed in the TSA group compared to the control were classified as being associated with putative biological processes or molecular function. Overall, in terms of putative biological processes, more nucleoside, nucleotide, and nucleic acid metabolism, protein metabolism and modification, signal transduction, developmental process, and cell cycle genes were differentially expressed between the TSA and control groups. In terms of putative molecular function, more nucleic acid-binding transcription factor and transferase genes were differentially expressed between the groups. The results collectively suggest that inhibition of histone acetylation in mouse embryos affects gene expression profiles at the time of zygotic genome activation, and this subsequently affects further development.


2007 ◽  
Vol 19 (1) ◽  
pp. 246
Author(s):  
A. Baji Gal ◽  
S. Mamo ◽  
S. Bodo ◽  
A. Dinnyes

Real-time PCR has the potential to accurately quantify the mRNA level of selected genes in single cells and individual pre-implantation-stage embryos. The goal of our study was to examine the variations in gene expression within individual embryos of the same stage and between embryos of the same stage but from different sources. In our study, we determined expression level of the 7 most commonly used housekeeping genes in 8-cell-stage mouse embryos produced under different culture conditions. Messenger RNA of 6 embryos each that was derived in vivo, or cultured in vitro from the zygote stage, or derived from oocytes activated parthenogenetically and developed in vitro were extracted individually followed by reverse transcription into cDNA. Optimized real-time PCR was performed for cytoplasmic beta-actin (Actb), glyceraldehyde-3-phosphate dehydrogenase (Gapdh), H2A histone family, member Z (H2afz), hypoxanthine guanine phosphoribosyl transferase 1 (Hprt1), ubiquitin C (Ubc), peptidylprolyl isomerase A (cyclophilin A) (Ppia), and eukaryotic translation elongation factor 1 epsilon 1 (Eef1e1) genes. The results were analyzed, and the percentage standard error of the mean relative expression value was compared for all genes. All 7 genes were presented above the detection limit in all samples. One or two individual embryos showed 2- to 4-fold higher mRNA levels than the average for all genes in the group. The embryos cultured in vitro showed much higher expression levels of H2afz, Ppia, and Eef1e1 genes than those in the in vivo group. The parthenogenetic group was similar to the in vivo group in expression of Actb, H2afz, Hprt, and Eef1e1 genes, but showed significant differences (P &lt; 0.05; Student's t-test) compared to the in vitro group (Table 1). The percent standard error of the mean decreased gradually as the number of samples was increased. The 6 individual embryos in similar groups showed relatively low variability compared to embryos at similar stage but produced in different conditions. Interestingly, the parthenogenetic embryos showed a level of gene expression comparable to that of the in vivo ones, notwithstanding their culture in vitro. In conclusion, morphological observations and similarity in developmental stage alone cannot guarantee the uniformity of embryo samples, and a minimum of 4–6 replicates per treatment is needed. Moreover, we showed that culture condition itself has an effect on housekeeping gene expression, which, if neglected, might result in misinterpretation of data. Table 1.Relative expression values of the different culture groups (mean ±SE; n =6 embryos) This work was supported by EU FP6 (MEXT-CT-2003-509582 and 518240), Wellcome Trust (Grant No. 070246), and Hungarian National Science Fund (OTKA) (Grant No. T046171).


2011 ◽  
Vol 23 (1) ◽  
pp. 199
Author(s):  
T. Somfai ◽  
K. Imai ◽  
M. Kaneda ◽  
S. Akagi ◽  
S. Haraguchi ◽  
...  

The aim of the present study was to investigate the effect of oocyte source and in vitro maturation (IVM) on the expression of selected genes in bovine oocytes and their contribution to in vitro embryo development. Follicular oocytes were collected either by ovum pick-up from live cows or by the aspiration of ovaries of slaughtered cows following storage in Dulbecco’s PBS at 15°C for overnight. In vitro maturation was performed according to the method of (Imai et al. 2006 J. Reprod. Dev. 52, 19–29 suppl.). Gene expression was assessed before and after IVM by real-time PCR. The following genes were investigated: GAPDH, G6PDH, ACTB, H2A, CCNB1, MnSOD, OCT4, SOX2, CX43, HSP70, GLUT8, PAP, GDF9, COX1, ATP1A1, CDH1, CTNNB1, AQP3, DYNLL1, DYNC 1/1, and PMSB1. In brief, mRNA was extracted from 20 oocytes per sample using a Qiagen RNeasy Micro Kit (Qiagen, Valencia, CA). Gene expression was analysed by a Roche Light Cycler 480 device and software (Roche, Indianapolis, IN). Relative expression of each gene was normalized to CCNB1, which in preliminary experiments appeared the most stably expressed irrespective of oocyte source and meiotic stage. Three replications were performed. Data were analysed by paired t-test. In immature ovum pick-up oocytes, genes related to metabolism (GAPDH, G6PDH, GLUT8) and stress (MnSOD, HSP70), and also OCT4, ATP1A1, and DYNC1/1 showed significantly (P < 0.05) higher expression compared with immature oocytes collected from slaughtered-stored ovaries. The expression of GDF9, GLUT8, CTNNB1, and PMSB1 was significantly (P < 0.05) reduced during IVM irrespective of the oocyte source. In a second experiment, IVF IVM oocytes showing an early (at 22 to 25 h after IVF) or late (at 27 to 30 h after IVF) first cleavage were either cultured in vitro or analysed for gene expression at the 2-cell stage. A higher (P < 0.05) rate of early-cleaving oocytes developed to the blastocyst stage compared with the rate of late-cleaving ones (46.2% v. 15.6%, respectively). Nevertheless, only ATP1A1 showed significantly reduced (P < 0.05) expression in late-cleaving embryos compared with early-cleaving ones. Our results suggest that although removal and storage of ovaries and IVM caused a reduction in the relative abundance of several genes in oocytes, in most cases, this did not affect embryo development. Among the genes studied, only ATP1A1 was correlated with in vitro development.


2009 ◽  
Vol 21 (1) ◽  
pp. 193
Author(s):  
G. D. Linger ◽  
C. L. Bormann ◽  
M. D. Peoples ◽  
M. C. Golding ◽  
C. R. Long

The proper removal of gametic epigenetic marks and coordinated re-establishment of the epigenome is critical to mammalian embryonic development. This global reprogramming of the embryonic genome includes fluctuations in both DNA methylation and histone modifications that are necessary to control chromatin structure and thus gene expression. In the bovine model, epigenetic changes occur from fertilization through blastocyst stages; in particular, and concurrent with the maternal-embryonic transition, de novo DNA methylation begins at the 8-cell stage. In order to understand which factors might be playing key roles in this epigenetic process, we used quantitative real-time PCR to characterize the temporal expression profiles of several genes involved in DNA and/or histone methylation: G9a, SetB1, Suv39h1, Suv420h1, SmyD3, Suz12, and LSH. Bovine ova and embryos were produced via in vitro maturation, fertilization, and culture from multiple pools of ova. Groups of 12–25 bovine ova or embryos, pooled at the 2-, 4 to 7-, mid 8-, late 8-, 12 to 16-cell, morula, and blastocyst stages, were washed twice through 1X PBS and stored in RNA lysis buffer at –80°C until further use. RNA was isolated from each sample using the RNeasy® Mini kit (Qiagen, Valencia, CA, USA), optimized for isolating RNA from single embryos, and treated to remove any contaminating genomic DNA. cDNA was generated with iScript™ reverse transcriptase (Bio-Rad Laboratories, Hercules, CA, USA) and diluted 1:10 with RNase/DNase-free water for further use in real-time PCR. Relative gene expression from each RNA sample was calculated in triplicate using the SYBR Green comparative Ct method (Applied Biosystems, Foster City, CA, USA) adjusted for individual PCR efficiencies (Bustin 2003) and normalized to the geometric mean Ct of 3 endogenous controls (GAPDH, YWHAZ, and SDHA) in order to account for differences in both cell number and amount of total mRNA present in each sample (Goossens et al. 2005). G9a and SetB1, both lysine-specific methyltransferases, were expressed at their highest levels in the metaphase II (MII) oocyte and 2-cell stage, before expression decreased gradually to basal levels by the morula and blastocyst stages. Suv39h1, Suv420h1, and SmyD3, also lysine-specific methyltransferases, all shared a similar pattern of expression: transcript levels were fairly high in the MII oocyte, increased at the 2-cell stage, then gradually dropped off around the 8–16-cell stage to basal levels by the morula stage. Interestingly, Suz12 and LSH both showed low expression from the MII oocyte until the 4 to 7-cell stage, increased dramatically at the 8-cell stage, then decreased again by the morula stage. Suz12 is a member of several Polycomb group complexes (PRCs); LSH associates with PRC-mediated gene silencing as well as DNMT3a and 3b. These data suggest that Suz12 and LSH may be implicated in bovine embryonic genome activation, while the latter genes are active during earlier cleavage events. Ongoing studies will evaluate the role of each of these epigenetic modifiers in bovine pre-implantation embryos by selective silencing via RNA interference.


2004 ◽  
Vol 16 (2) ◽  
pp. 248
Author(s):  
C. Wrenzycki ◽  
T. Brambrink ◽  
D. Herrmann ◽  
J.W. Carnwath ◽  
H. Niemann

Array technology is a widely used tool for gene expression profiling, providing the possibility to monitor expression levels of an unlimited number of genes in various biological systems including preimplantation embryos. The objective of the present study was to develop and validate a bovine cDNA array and to compare expression profiles of embryos derived from different origins. A bovine blastocyst cDNA library was generated. Poly(A+)RNA was extracted from in vitro-produced embryos using a Dynabead mRNA purification kit. First-strand synthesis was performed with SacIT21 primer followed by randomly primed second-strand synthesis with a DOP primer mix (Roche) and a global PCR with 35 cycles using SacIT21 and DOP primers. Complementary DNA fragments from 300 to 1500bp were extracted from the gel and normalized via reassoziation and hydroxyapatite chromatography. Resulting cDNAs were digested with SacI and XhoI, ligated into a pBKs vector, and transfected into competent bacteria (Stratagene). After blue/white colony selection, plasmids were extracted and the inserts were subjected to PCR using vector specific primers. Average insert size was determined by size idenfication on agarose gels stained with ethidium bromide. After purification via precipitation and denaturation, 192 cDNA probes were double-spotted onto a nylon membrane and bound to the membrane by UV cross linking. Amplified RNA (aRNA) probes from pools of three or single blastocysts were generated as described recently (Brambrink et al., 2002 BioTechniques, 33, 3–9) and hybridized to the membranes. Expression profiles of in vitro-produced blastocysts cultured in either SOF plus BSA or TCM plus serum were compared with those of diploid parthenogenetic ones generated by chemical activation. Thirty-three probes have been sequenced and, after comparison with public data bases, 26 were identified as cDNAs or genes. Twelve out of 192 (6%) seem to be differentially expressed within the three groups;; 7/12 (58%) were down-regulated, 3/12 (25%) were up-regulated in SOF-derived embryos, and 2/12 (20%) were up-regulated in parthenogenetic blastocysts compared to their in vitro-generated counterparts. Three of these genes involved in calcium signaling (calmodulin, calreticulin) and regulation of actin cytoskeleton (destrin) were validated by semi-quantitative RT-PCR (Wrenzycki et al., 2001 Biol. Reprod. 65, 309–317) employing poly(A+) RNA from a single blastocyst as starting material. No differences were detected in the relative abundance of the analysed gene transcripts within the different groups. These findings were confirmed employing the aRNA used for hybridization in RT-PCR and showed a good representativity of the selected transcripts. Results indicate that it is possible to construct a homologous cDNA array which could be used for gene expression profiling of bovine preimplantation embryos. Supported by the Deutsche Forschungsgemeinschaft (DFG Ni 256/18-1).


2012 ◽  
Vol 442 (1) ◽  
pp. 38-41 ◽  
Author(s):  
N. Yu. Sakharova ◽  
L. N. Markova ◽  
A. A. Smirnov ◽  
E. F. Vikhlyantseva ◽  
L. A. Fialkovskaya ◽  
...  

Development ◽  
1980 ◽  
Vol 60 (1) ◽  
pp. 419-428
Author(s):  
Brigid Hogan ◽  
Martha Spiegelman ◽  
Dorothea Bennett

Inner cell masses (ICMs) isolated immunosurgically from mouse blastocysts segregating the homozygous lethal mutants t0/t0 and tw5/tw5 were cultured in vitro. Presumed t0/t0 ICMs fail to grow after three days in culture (equivalent gestational day 7·5) when they consist of an outer layer of endoderm cells surrounding about 30 epiblast cells. Presumed homozygous tw5/tw5 ICMs develop to a more advanced stage in culture and on the seventh day (equivalent gestational day 11·5) consist of an inner core of disorganized ectoderm cells with a small proamniotic cavity, surrounded by multiple layers of endoderm cells.


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