Chromatin remodelling and nuclear reprogramming at the onset of embryonic development in mammals

1998 ◽  
Vol 10 (8) ◽  
pp. 573 ◽  
Author(s):  
Jean-Paul Renard
Keyword(s):  
Normal Development ◽  
Blastocyst Stage ◽  
Chromatin Remodelling ◽  
Chromatin Organization ◽  
Nuclear Reprogramming ◽  
Cell Stage ◽  
Donor Nucleus ◽  
The One ◽  
Kinetics Of ◽  
Determining Factor

Two main strategies are used to produce cloned mammals. The first involves the condensation of donor chromatin into chromosomes directly exposed to the recipient cytoplasm, whereas the second leaves the donor nucleus in interphase until the time of the first mitosis. Both strategies, which induce marked changes in chromatin organization, allow full reprogrammation of somatic-differentiated fetal and adult cells. This paper reviews some of the recent data that contribute to our understanding of chromatin remodelling at the onset of normal development, as well as after the introduction of a foreign nucleus into a recipient enucleated oocyte. These data indicate that the coordinated changes in chromatin organization that take place up until the first cellular differentiations at the blastocyst stage are determinants for successful cloning. Although some degree of synchronization between the cell cycle stages of donor and recipient cells is necessary for correct remodelling of a transferred nucleus, the kinetics of remodelling events occurring during the one-cell stage appears to be the determining factor for the normal onset of gene expression.

scholarly journals Successful production of offspring after superovulation and in vitro culture of embryos from domestic ferrets (Mustela putorius furos)

Reproduction ◽  
2001 ◽  
pp. 611-618 ◽  
Author(s):  
ZY Li ◽  
QS Jiang ◽  
YL Zhang ◽  
XM Liu ◽  
JF Engelhardt
Keyword(s):  
Genetic Manipulation ◽  
Blastocyst Stage ◽  
Chorionic Gonadotrophin ◽  
Mustela Putorius ◽  
Cell Stage ◽  
Fetal Bovine ◽  
The One ◽  
Genetic Modelling ◽  
Successful Production

In an effort to expand the use of ferrets as models for genetic disease, several experimental parameters that are required for successful genetic manipulation in this species were investigated. Optimum superovulation (19.3 +/- 0.6 oocytes and embryos per female) was achieved after injections of 100 iu equine chorionic gonadotrophin (eCG) and 150 iu human chorionic gonadotrophin (hCG). The ovulation rate achieved by the treatment was more than double that induced by mating. Mating with a male immediately after hCG treatment did not significantly alter the number of oocytes ovulated or the number of embryos present, indicating that mating is not required for superovulation in ferrets. Of embryos harvested at the one-cell stage, 64.5% and 47.1% developed into blastocysts when cultured in vitro in CZB or TCM-199 plus 10% fetal bovine serum (FBS) media, respectively. In contrast, only 17.1% of embryos cultured in vitro in NCSU-23 developed to the blastocyst stage. Both freshly retrieved and in vitro cultured embryos from cinnamon-coloured parents produced live young when transferred at the eight-cell stage into albino, pseudo-pregnant recipients. The percentage of kits delivered relative to embryos transferred was 61% for freshly retrieved embryos and 32% for embryos cultured in vitro. These results demonstrate successful embryo transfer in ferrets and provide a basis for further study of genetic modelling approaches in this species after embryo manipulation.

103 BIRTH OF CLONED PIGLETS DERIVED FROM AN OPTIMIZED IN VITRO BLASTOCYST PRODUCTION SYSTEM BY TRICHOSTATIN A TREATMENT

2007 ◽  
Vol 19 (1) ◽  
pp. 168
Author(s):  
Y.-H. Zhang ◽  
Y.-T. Du ◽  
K. Zhang ◽  
J. Li ◽  
P. M. Kragh ◽  
...  
Keyword(s):  
Culture Media ◽  
Trichostatin A ◽  
Blastocyst Stage ◽  
Control Group ◽  
Blastocyst Development ◽  
Cell Stage ◽  
Deacetylase Inhibitor ◽  
The One ◽  
Effective Group

The present study was designed to examine the effect of trichostatin A (TSA, a histone deacetylase inhibitor) treatment on in vitro developmental ability of pig cloned embryos and to evaluate the feasibility of producing piglets from these embryos. Cell lines were established from 40-day-old fetuses, and adult ear skin was used as nuclear donor. In vitro-matured oocytes from abattoir-derived sow ovaries were used as cytoplast recipients for micromanipulator-assisted somatic cell nuclear transfer (SCNT). Data were analyzed by using SPSS (11.0) with one-way ANOVA, and each experiment was replicated at least 3 times. In Experiment 1, immediately after simultaneous fusion and activation, the reconstructed couplets were randomly cultured in porcine zygote medium 3 (PZM3; Yoshioka et al. 2002 Biol. Reprod. 66, 112–119) with 10 �g mL-1 cytochalasin B (CB), 10 �g mL-1 cycloheximide (CHX), and 0 nM, 5 nM, or 50 nM TSA for the first 4 h. Cloned embryos (fused reconstructed couplets) were moved to the same culture media but without CB and CHX and further cultured at 38.5�C, under 5% CO2, 5% O2, 90% N2 and 100% humidity. After incubation for a total of 8–14 h in 50 nM, 19–24 h in 50 nM or 5 nM, and 31–36 h in 50 nM TSA in PZM3 (0 nM TSA serves as control for each group), the embryos were further cultured in vitro without TSA in PZM3 for up to 168 h. Cleavage and blastocyst development rates, based on embryos cultured, were recorded at 48 and 168 h of IVC, respectively. Results showed that 50 nM TSA treatment for 19-24 h supported a higher blastocyst development rate than the control group [No. blastocysts/No. embryos cultured (mean � SEM): 107/258, 47.4 � 5.9% vs. 65/324, 20.0 � 2.3%, respectively; P < 0.05], whereas similar pre-implantation development was obtained between the other 3 test groups and the control. In Experiment 2, TSA-treated cloned embryos at the one-cell stage or blastocyst stage were transferred to recipients to examine the possibility of producing piglets. Ten cloned piglets (2 are healthy and 8 died shortly after birth) and one ongoing pregnancy were obtained from 3 recipients who received an average of 110 one-cell stage embryos, whereas 4 piglets originating from traditional cloning were produced from one recipient which received 28 traditional cloned blastocysts (produced from the effective group in Experiment 1) and 30 handmade but non-TSA-treated ones. Our data demonstrate that TSA treatment after SCNT in porcine can significantly improve the in vitro blastocyst production, and embryos treated with TSA could support full-term development and result in healthy offspring.

288 KINETICS OF FERTILIZATION, DEVELOPMENT, AND SEX RATIO OF IN VITRO-PRODUCED BOVINE EMBRYOS OBTAINED WITH FOUR DIFFERENT BULLS

2007 ◽  
Vol 19 (1) ◽  
pp. 259 ◽  
Author(s):  
M. Alomar ◽  
H. Tasiaux ◽  
S. Remacle ◽  
F. George ◽  
D. Paul ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Time Lapse ◽  
Blastocyst Stage ◽  
Bovine Embryos ◽  
In Vitro Production ◽  
Chi Square ◽  
Cell Stage ◽  
Chi Square Test ◽  
Kinetics Of

The between-bulls variation in in vitro fertility and the shift of sex ratio toward male embryos are two problems affecting the in vitro production (IVP) of bovine embryos. Our objective was to evaluate the possible correlation between the kinetics of fertilization, embryo development, and the sex ratio of the resulting embryos. In a first experiment, and using frozen-thawed semen of 4 different AI bulls, the kinetics of pronucleus (PN) formation was evaluated at 8, 12, and 18 h post-in vitro insemination (hpi) after fixation and staining with Hoechst 33342. Fertilized oocytes were classified in 3 PN stages: PN1: showing the first signs of sperm head decondensation; PN2: with two pronuclei of different sizes, the two being far from each other; and PN3: showing two symmetric pronuclei of equal size, close to each other. Differences between bulls were observed at each time point, but were greater at 12 hpi than at 8 or 18 hpi. At 8 hpi and 12 hpi, bull C showed a significantly faster PN formation by comparison with the 3 other bulls (chi-square test: P < 0.05), whereas at 18 hpi, the proportion at each of the PN stages was similar to that of bulls A and D, with bull B showing delayed PN development. In a second experiment, a standard IVP procedure was conducted with the 4 bulls to determine cleavage and blastocyst rates. The timing of first cleavage was measured using time-lapse cinematography. Compared with those of bull B, the embryos generated with bull C led to significantly higher Day 7 blastocyst yields (31.3 � 9.5% vs. 21.9 � 6.7%; ANOVA: P < 0.05). Moreover, the embryos from bull C reaching the blastocyst stage cleaved faster (first cleavage at 23.1 � 2.1 hpi vs. 25.4 � 2.7 hpi for bull B; ANOVA: P < 0.05). In a third experiment, 65 to 76 Day 8 blastocysts were sexed per bull. Embryo sexing was performed by PCR using the co-amplification of a Y-specific bovine SRY sequence and an autosomal btRep-137 sequence. Only blastocysts obtained with bull C showed a shift in sex ratio toward male embryos (76.0% male embryos vs. 53.8% for bull B; chi-square test: P < 0.05), whatever the size of the blastocyst. The shift in sex ratio was already present at the 2-cell stage (64.2% male embryos; n = 53; chi-square test: P < 0.05). In conclusion, for 2 out of 4 bulls, a correlation was observed between the kinetics of PN formation, the timing of first cleavage, and the sex ratio of the resulting embryos.

scholarly journals Inositol transport in mouse oocytes and preimplantation embryos: effects of mouse strain, embryo stage, sodium and the hexose transport inhibitor, phloridzin

Reproduction ◽  
2003 ◽  
pp. 111-118 ◽  
Author(s):  
BD Higgins ◽  
MT Kane
Keyword(s):  
Gene Activation ◽  
Blastocyst Stage ◽  
Preimplantation Embryos ◽  
Cell Stage ◽  
Sodium Dependent ◽  
Morula Stage ◽  
Zygotic Gene ◽  
Zygotic Gene Activation ◽  
The One ◽  
Inositol Uptake

The uptake of myo-inositol by mouse oocytes and preimplantation embryos of a crossbred (DBA x C57BL/6) and a purebred outbred strain (MF1) was measured using [2-(3)H]myo-inositol. Uptake in crossbred embryos increased about 15-fold between the one- and two-cell stages and increased again by about sixfold at the blastocyst stage compared with the morula stage. Uptake in purebred embryos increased about 42-fold between the one- and two-cell stages and increased more than threefold at the blastocyst stage compared with the morula stage. In all stages examined, except two-cell crossbred embryos, inositol uptake was, depending on the stage, either largely or partly sodium dependent and could be inhibited by the sodium-dependent hexose transport inhibitor, phloridzin. This is consistent with the hypothesis that transport occurs via a sodium myo-inositol transporter (SMIT) protein. In addition, there was strong evidence that a sodium-independent mechanism of uptake, possibly a channel, was switched on at the two-cell stage coincident with zygotic gene activation which resulted in 141-fold and 71-fold increases in sodium-independent uptake from the one-cell to two-cell stages in crossbred and purebred embryos, respectively. This mechanism was either abolished or drastically downregulated at the blastocyst stage, whereas sodium-dependent uptake was markedly upregulated. In two-cell crossbred embryos, there was a complete abolition of sodium-dependent uptake, again possibly regulated by zygotic gene activation. The hypothesis that the changes in mechanism of inositol uptake at about the two-cell stage are due to zygotic gene activation was supported by the finding that these changes did not occur in parthenogenetic two-cell embryos.

scholarly journals 272OVUM RECOVERY AND BLASTOCYST DEVELOPMENT FOLLOWING INTRACYTOPLASMIC SPERM INJECTION IN CHIMPANZEES

2004 ◽  
Vol 16 (2) ◽  
pp. 256
Author(s):  
I. Hayasaka ◽  
N. Yoshimoto ◽  
Y. Mori ◽  
K. Suzuki ◽  
R. Honda ◽  
...  
Keyword(s):  
Intracytoplasmic Sperm Injection ◽  
Cumulus Cells ◽  
Fertilization Rate ◽  
Blastocyst Stage ◽  
Early Embryogenesis ◽  
Blastocyst Development ◽  
Cell Stage ◽  
Morula Stage ◽  
The One ◽  
Estradiol Levels

In the present study, we report on oocyte collection, intracytoplasmic sperm injection and early embryogenesis in chimpanzees. Eight adult female chimpanzees, 11–27 years of age, received a single s.c. injection of 3.75mg GnRH (Leuplin, Takeda Co. Ltd., Osaka, Japan) 1 to 3 days after the beginning of menstruation. Daily i.m. injections of hMG (Humegon, Nippon Organon K.K., Tokyo, Japan) were initiated the following day. The dose of hMG was altered from 75 to 300IU according to serum estradiol levels. When at least one follicle of 17mm or more in diameter was observed, 10000IU of hCG (Pregnyl, Nippon Organon K.K.) were administered by i.m injection. Oocytes were recovered by ultrasound-guided transvaginal follicular aspiration 30.5 to 35.5h after hCG injection. Mature oocytes were denuded of cumulus cells by treatment with 0.1% hyaluronidase, and injected with a frozen-thawed or fresh spermatozoan using a Piezo-driven micromanipulator. Zygotes were cultured in Quinn’s Advantage Fertilization Medium (Cooper Surgical, Inc., Trumbull, CT, USA) with 10 serum protein substitute (SPS) at 37°C in a 5% CO2 atmosphere until the pronucleus stage. The medium was replaced by Quinn’s Advantage Cleavage Medium with 10 SPS from the pronuclear to 8-cell stage, and Quinn’s Advantage Blastcyst Medium with 10 SPS, thereafter. Mild ovarian hyperstimulation syndrome (OHSS) occurred in one female chimpanzee with estradiol levels of 7520pgmL−1. No oocytes were collected from 2 chimpanzees in which large follicles were observed. Thirty-five mature oocytes, one immature oocyte and 6 degenerate/fragmented oocytes were retrieved from 6 chimpanzees, including the one with OHSS. Among 35 mature oocytes injected with spermatozoa, 26 oocytes (74%) produced two pronuclei;; 23 zygotes (66%) cleaved to the 2-cell stage, 22 (63%) to the 4-cell stage, 14 (40%) to the 8-cell stage, and 9 (26%) to the morula stage. Seven zygotes (20%) developed to the blastocyst stage by 120h. There were no differences in fertilization rate or early embryogenesis between frozen and fresh spermatozoa. Results indicate that techniques used for human-assisted reproduction may be applicable to the chimpanzee to help preserve this endangered species.

scholarly journals Embryo culture in presence of oviductal fluid induces DNA methylation changes in bovine blastocysts

Reproduction ◽  
2017 ◽  
Vol 154 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Antonio D Barrera ◽  
Elina V García ◽  
Meriem Hamdi ◽  
María J Sánchez-Calabuig ◽  
Ángela P López-Cardona ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Blastocyst Stage ◽  
Early Embryo ◽  
Cpg Methylation ◽  
Bovine Embryos ◽  
Cell Stage ◽  
The One ◽  
Genomic Regions ◽  
Oviductal Fluid

During the transit through the oviduct, the early embryo initiates an extensive DNA methylation reprogramming of its genome. Given that these epigenetic modifications are susceptible to environmental factors, components present in the oviductal milieu could affect the DNA methylation marks of the developing embryo. The aim of this study was to examine if culture of bovine embryos with oviductal fluid (OF) can induce DNA methylation changes at specific genomic regions in the resulting blastocysts. In vitro produced zygotes were cultured in medium with 3 mg/mL bovine serum albumin (BSA) or 1.25% OF added at the one- to 16-cell stage (OF1–16), one- to 8-cell stage (OF1–8) or 8- to 16-cell stage (OF8–16), and then were cultured until Day 8 in medium with 3 mg/mL BSA. Genomic regions in four developmentally important genes (MTERF2, ABCA7, OLFM1, GMDS) and within LINE-1 retrotransposons were selected for methylation analysis by bisulfite sequencing on Day 7–8 blastocysts. Blastocysts derived from OF1–16 group showed lower CpG methylation levels in MTERF2 and ABCA7 compared with the BSA group. However, CpG sites within MTERF2, ABCA7 and OLFM1 showed higher methylation levels in groups OF1–8 and OF8–16 than in OF1–16. For LINE-1 elements, higher CpG methylation levels were observed in blastocysts from the OF1–16 group than in the other experimental groups. In correlation with the methylation changes observed, mRNA expression level of MTERF2 was increased, while LINE-1 showed a decreased expression in blastocysts from OF1–16 group. Our results suggest that embryos show transient sensitivity to OF at early stages, which is reflected by specific methylation changes at the blastocyst stage.

Culture of porcine embryos from the one- and two-cell stage to the blastocyst stage in sheep oviducts

1991 ◽  
Vol 35 (6) ◽  
pp. 1147-1151 ◽  
Author(s):  
R.S. Prather ◽  
M.M. Sims ◽  
N.L. First
Keyword(s):  
Blastocyst Stage ◽  
Cell Stage ◽  
The One

Nuclear cytoplasmic interactions following nuclear transplantation in mouse embryos

Development ◽  
1987 ◽  
Vol 101 (4) ◽  
pp. 915-923 ◽  
Author(s):  
S.K. Howlett ◽  
S.C. Barton ◽  
M.A. Surani
Keyword(s):  
Cell Nucleus ◽  
Blastocyst Stage ◽  
Mouse Embryos ◽  
Nuclear Transplantation ◽  
Cell Nuclei ◽  
Cell Stage ◽  
Cell Donor ◽  
Donor Nucleus ◽  
Cell Embryo

We have investigated the development of reconstituted embryos in which enucleated 1- or 2-cell embryos received various advanced nuclei. Enucleated 1-cells developed to the blastocyst stage only when an early 2-cell donor nucleus was transferred but very rarely if the donor nucleus was derived from a late 2-cell, early 4-cell or mid 8-cell embryo. Although an 8-cell nucleus could only support development of an enucleated zygote to the 2-cell stage, it did express the hsp 68/70 X 10(3) Mr proteins that are characteristic of the first embryonic gene activity. These polypeptides were absent in enucleated zygotes that did not receive a donor nucleus. Moreover, an 8-cell nucleus transferred to an enucleated late 2-cell blastomere could also support preimplantation development provided that the nuclear:cytoplasmic ratio was maintained as in intact 2-cell blastomeres. 8-cell nuclei transferred to zygotes that retained at least one pronucleus were able to support development to the blastocyst stage provided that the pronucleus was both fully transcriptionally active and present beyond the late 1-cell stage. This study suggests an active and continued helper role of the resident pronucleus for the participation by an 8-cell nucleus in reconstituted eggs.

126 NUCLEAR TRANSLOCATION OF NUCLEAR FACTOR KAPPA B AND ITS ROLE IN MOUSE PRE-IMPLANTATION DEVELOPMENT

2006 ◽  
Vol 18 (2) ◽  
pp. 172
Author(s):  
Y. Fumiiwa ◽  
H. Imai ◽  
M. Yamada
Keyword(s):  
Treatment Group ◽  
Nuclear Factor Kappa B ◽  
Nuclear Translocation ◽  
Blastocyst Stage ◽  
Control Group ◽  
Nuclear Factor ◽  
Cell Stage ◽  
Nuclear Factor Kappa ◽  
Morphological Aberration ◽  
The One

In mouse pre-implantation development, it has been reported that RelA, one of the subunits of nuclear factor kappa B (NF-�B), is expressed in eggs and embryos from the Metaphase II oocyte to the blastocyst stage. However, the role of NF-�B in the pre-implantation development has not yet been elucidated in detail. In this study, we examined (1) the activation of NF-�B during mouse pre-implantation development and (2) the effect of a synthetic peptide inhibitor of NF-�B, SN-50, which inhibits nuclear translocation of NF-�B on the pre-implantation development. Fertilized one-cell embryos were collected 17 h post-hCG from the ampullae of oviducts of superovulated ICR mouse females that had been mated with the same strain of males and then were cultured in KSOM medium at 37�C under 5% CO2 in air for 4 d. To elucidate the timing of NF-�B activation, we examined the localization of NF-�B in the nucleus by an immunofluorescence approach using RelA antibody with a laser confocal microscope. RelA was distributed mainly in the cytoplasm of embryos from the one-cell stage through the blastocyst stages. The presence of RelA in the nucleus, evidence for NF-�B activation, was observed in embryos from the one-cell to the compacted 8-cell stages. Moreover, we observed RelA punctate localization in nucleoplasm of embryos from the one-cell to the 4-cell stages, and nuclear dots were enriched conspicuously in the one-cell embryos and the late 2-cell embryos. These results suggest that NF-�B is activated in embryos from the one-cell to the compacted 8-cell stages and that its activation seems to be particularly strong at the developmental stage when RelA appeared to be concentrated in nuclear dots, as it has been reported that NF-�B and other transcription factors and co-activators form punctate structures called 'enhanceosom' in association with particular promoters in the nucleus. Next, we examined the effect of SN-50 on the pre-implantation development of mouse embryos. When embryos were treated with SN-50 at 20 �g/mL from the 2-cell stage, 63% (33 of 52) of the embryos developed to blastocysts, but 55% (18 of 33) of the blastocysts showed abnormal morphology, such as poor cavitation, and many degenerating cells extruded into the perivitelline space. The percentages of 2-cell embryos that formed morphologically normal blastocysts were significantly lower in the SN-50 treatment group (29%; 15 of 52) than in the untreated control group (76%; 35 of 46) and in the SN-50M (inactive analogue of SN-50, 20 �g/mL) treatment group (72%; 38 of 53). These experiments were done in 4 replicates, and the statistical analyses of the data were done by ANOVA and Fisher's PLSD test. Nuclear location of RelA was not observed in the embryos at the 4-cell stage when treated with SN-50 from the 2-cell stage, although observed in control and SN-50M-treated embryos. Furthermore, it was found that most of embryos (23 of 37) treated with SN-50 from the compacted 8-cell or morula stages developed normally to the blastocyst stage as control embryos (25 of 36). These results suggest that morphological aberration at the blastocyst stage is elicited by inhibiting NF-�B activation.

Abnormalities in the transcription of reprogramming genes related to global epigenetic events of cloned endangered felid embryos

2010 ◽  
Vol 22 (4) ◽  
pp. 613 ◽  
Author(s):  
S. Imsoonthornruksa ◽  
C. Lorthongpanich ◽  
A. Sangmalee ◽  
K. Srirattana ◽  
C. Laowtammathron ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Cell Division ◽  
Nuclear Genome ◽  
Blastocyst Stage ◽  
Transcript Expression ◽  
Transcript Levels ◽  
Donor Nucleus ◽  
Epigenetic Events ◽  
Low Levels ◽  
The One

The present study examined transcription levels of the Oct4, DNMT1, DNMT3a, DNMT3b, HAT1 and HDAC1 genes in cloned felid embryos developing from single one-cell to blastocyst stages. IVF, cloned domestic and leopard cat embryos had low Oct4 and HAT1 levels during the early stages, but transcript expression increased at the eight-cell and blastocyst stages. In contrast, expression in the cloned marble cat embryos was low at all stages. Transcription patterns of HDAC1 were altered in cloned embryos compared with IVF embryos. Transcription levels of DNMT1 decreased markedly throughout development of both IVF and cloned embryos. In IVF embryos, DNMT3a transcripts rarely appeared in the four- to eight-cell stages, but levels increased in the morula to blastocyst stages. In contrast, in cloned embryos, DNMT3a transcript levels were high at the one- to two-cell stages, decreased during subsequent cell division and then increased again at the blastocyst stage. The IVF and cloned embryos showed similar DNMT3b transcription patterns, starting with low levels at the two-cell to morula stages and reaching a maximum at the blastocyst stage. These results suggest that the low level of Oct4 transcripts may be responsible, in part, for the failure of blastocyst production in the cloned marbled cat. However, higher transcription of the DNA methylation genes and lower transcription of the histone acetylation genes were observed in cloned compared with IVF embryos, suggesting that the felids’ donor nucleus could not completely reprogramme the nuclear genome and so the re-establishment of embryonic totipotency was not achieved.

Sign in / Sign up

Export Citation Format

Share Document