15 HISTONE ACETYLATION PROFILE OF PORCINE EMBRYOS PRODUCED BY 2 CLONING METHODS WITH OR WITHOUT IN VITRO CULTURE

2016 ◽  
Vol 28 (2) ◽  
pp. 137
Author(s):  
Y. Liu ◽  
A. Lucas-Hahn ◽  
B. Petersen ◽  
R. Li ◽  
D. Hermann ◽  
...  

Conventional “Dolly”-based cloned (CNT) embryos maintain zona pellucida and can be transferred early in development. Handmade cloned (HMC) embryos are zona free and are cultured to later stages for transfer. We have shown differences between HMC and CNT embryos (Rep. Fert. Dev. 26, 123), and both in vitro culture and cloning method (NT) are associated with alterations in histone acetylation. More studies are needed to clarify whether CNT and HMC embryos differ in epigenetic profiles due to NT method or culture condition. Here we investigated histone acetylation profile of NT embryos produced by CNT or HMC with or without 5 to 6 days in vitro culture, emphasising quality and gene expression in resulting embryos. Both NT methods were performed on Day 0 (D0) with same oocyte batch, donor cells, and culture medium (CNT in group, HMC in well of well). On D0, 5, and 6 after CNT (Clon. Stem Cells 10, 355) or HMC (Zygote 20, 61), all developed embryos of all morphological qualities were collected for immunostaining of H3K18ac, and on D0 and 6 for mRNA expression of the genes KAT2A/2B, EP300, HDAC1/2, DNMT1o/s, and GAPDH. Embryo quality was evaluated normal (clear inner cell mass, high cell number, no fragments) or bad (no clear inner cell mass, low cell number, fragments). Cell numbers per blastocyst were counted on D5 and 6. Differences in cell number and H3K18ac level between different groups and days were analysed by ANOVA; gene expression data were analysed by GLM (SAS version 9.3, SAS Institute Inc., Cary, NC, USA). Embryo development rates of both NT methods were reported previously (Rep. Fert. Dev. 26, 123). On D5 and 6, all HMC embryos were evaluated as normal, but the CNT group contained both normal and bad embryos. Regarding cell numbers (Table 1), on D5 there was no difference between normal CNT and HMC embryos, but numbers were lower in CNT bad embryos. On D6 the blastocyst cell number was lower in both normal and bad CNT embryos compared with HMC. Regarding H3K18ac levels (Table 1), no differences were found on D5 between normal CNT and HMC embryos, but on D6 both CNT normal and bad embryos had higher H3K18ac level compared with HMC. On D0, no difference was found in mRNA expression of all 8 genes. On D6, KAT2A expression was slight increased (1.8-fold) in CNT compared with HMC embryos (P < 0.05). In conclusion, no differences were found between CNT and HMC embryos after completed NT procedure (D0) or after 5 days in vitro culture. However, differences in quality (cell number and H3K18ac) and gene expression between the 2 NT methods were observed when blastocyst expansion was initiated (D6). Thus, the 2 NT methods seem to produce embryos of similar quality, which is maintained over 5 days in vitro culture, but thereafter gene expression and histone acetylation are more active in CNT embryos. Table 1.Cell number and H3K18ac level1

Development ◽  
1989 ◽  
Vol 107 (3) ◽  
pp. 597-604 ◽  
Author(s):  
K. Hardy ◽  
A.H. Handyside ◽  
R.M. Winston

The development of 181 surplus human embryos, including both normally and abnormally fertilized, was observed from day 2 to day 5, 6 or 7 in vitro. 63/149 (42%) normally fertilized embryos reached the blastocyst stage on day 5 or 6. Total, trophectoderm (TE) and inner cell mass (ICM) cell numbers were analyzed by differential labelling of the nuclei with polynucleotide-specific fluorochromes. The TE nuclei were labelled with one fluorochrome during immunosurgical lysis, before fixing the embryo and labelling both sets of nuclei with a second fluorochrome (Handyside and Hunter, 1984, 1986). Newly expanded normally fertilized blastocysts on day 5 had a total of 58.3 +/− 8.1 cells, which increased to 84.4 +/− 5.7 and 125.5 +/− 19 on days 6 and 7, respectively. The numbers of TE cells were similar on days 5 and 6 (37.9 +/− 6.0 and 40.3 +/− 5.0, respectively) and then doubled on day 7 (80.6 +/− 15.2). In contrast, ICM cell numbers doubled between days 5 and 6 (20.4 +/− 4.0 and 41.9 +/− 5.0, respectively) and remained virtually unchanged on day 7 (45.6 +/− 10.2). There was widespread cell death in both the TE and ICM as evidenced by fragmenting nuclei, which increased substantially by day 7. These results are compared with the numbers of cells in morphologically abnormal blastocysts and blastocysts derived from abnormally fertilized embryos. The nuclei of arrested embryos were also examined. The number of TE and ICM cells allocated in normally fertilized blastocysts appears to be similar to the numbers allocated in the mouse. Unlike the mouse, however, the proportion of ICM cells remains higher, despite cell death in both lineages.


Reproduction ◽  
2007 ◽  
Vol 133 (1) ◽  
pp. 231-242 ◽  
Author(s):  
Craig Smith ◽  
Debbie Berg ◽  
Sue Beaumont ◽  
Neil T Standley ◽  
David N Wells ◽  
...  

During somatic cell nuclear transfer (NT), the transcriptional status of the donor cell has to be reprogrammed to reflect that of an embryo. We analysed the accuracy of this process by comparing transcript levels of four developmentally important genes (Oct4,Otx2,Ifitm3,GATA6), a gene involved in epigenetic regulation (Dnmt3a) and three housekeeping genes (β-actin, β-tubulinandGAPDH) in 21 NT blastocysts with that in genetically half-identicalin vitroproduced (IVP,n=19) andin vivo(n=15) bovine embryos. We have optimised an RNA-isolation and SYBR-green-based real-time RT-PCR procedure allowing the reproducible absolute quantification of multiple genes from a single blastocyst. Our data indicated that transcript levels did not differ significantly between stage and grade-matched zona-free NT and IVP embryos except for Ifitm3/Fragilis, which was expressed at twofold higher levels in NT blastocysts.Ifitm3expression is confined to the inner cell mass at day 7 blastocysts and to the epiblast in day 14 embryos. No ectopic expression in the trophectoderm was seen in NT embryos. Gene expression in NTand IVP embryos increased between two- and threefold for all eight genes from early to late blastocyst stages. This increase exceeded the increase in cell number over this time period indicating an increase in transcript number per cell. Embryo quality (morphological grading) was correlated to cell number for NT and IVP embryos with grade 3 blastocysts containing 30% fewer cells. However, only NT embryos displayed a significant reduction in gene expression (50%) with loss of quality. Variability in gene expression levels was not significantly different in NT, IVP orin vivoembryos but differed among genes, suggesting that the stringency of regulation is intrinsic to a gene and not affected by culture or nuclear transfer.Oct4levels exhibited the lowest variability. Analysing the total variability of all eight genes for individual embryos revealed thatin vivoembryos resembled each other much more than did NT and IVP blastocysts. Furthermore,in vivoembryos, consisting of 1.5-fold more cells, generally contained two- to fourfold more transcripts for the eight genes than did their cultured counterparts. Thus, culture conditions (in vivoversusin vitro) have greater effects on gene expression than does nuclear transfer when minimising genetic heterogeneity.


2021 ◽  
Vol 2 ◽  
Author(s):  
Lydia K. Wooldridge ◽  
Alan D. Ealy

Previous work determined that bovine interleukin-6 (IL6) increases inner cell mass (ICM), primitive endoderm (PE), and total cell number in in vitro produced (IVP) bovine blastocysts. Another IL6 family member, leukemia inhibitory factor (LIF), has the potential to produce the same effects of IL6 due to the presence of its receptor in bovine blastocysts. We compared the abilities of LIF and IL6 to increase ICM cell numbers in day 7, 8, and 9 IVP bovine blastocysts. Supplementation with 100 ng/ml LIF from day 5 onward improved blastocyst formation rates on days 7 and 8 similar to what was observed when supplementing 100 ng/ml IL6. However, LIF supplementation did not cause an increase in ICM numbers like was observed after supplementing IL6. On day 9, increases in PE cell numbers were detected after LIF supplementation, but 300 ng/ml LIF was required to achieve the same effect on PE numbers that was observed by providing 100 ng/ml IL6. Collectively, these results show that LIF can mimic at least some of the effects of IL6 in bovine blastocyst.


2004 ◽  
Vol 16 (2) ◽  
pp. 186
Author(s):  
J.O. Gjørret ◽  
P. Maddox-Hyttel

Regulation of apoptosis may be affected by factors during preimplantation development, and this is possibly related to embryo developmental potential. Here we investigate differences in the incidence of apoptotic nuclei in Day 7 bovine blastocysts produced by two different in vivo and three different in vitro methods. In vivo embryos were produced either by a regular superovulation procedure (reg group; n=29; Laurincik et al., 2003, Mol. Reprod. Dev. 65, 73–85), or by postponement of the LH surge (pp group; n=35; van de Leemput et al., 2001, Therio. 55, 573–592). In vitro embryos were derived from systems using either co-culture (cc group; n=30, Avery and Greve 2000, Mol. Reprod. Dev. 55, 438–445), or culture in synthetic oviduct fluid (SOF) with (S+group; n=35) or without serum (S− group; n=38; Holm et al., 1999, Theriogenology, 52, 683–700). Embryos were collected at approx. 168h post ovulation/insemination and subjected to chromatin staining and detection of DNA degradation by TUNEL reaction. The total number of nuclei, number of nuclei displaying apoptotic morphology (+M), number of nuclei displaying TUNEL reaction (+T), and number of nuclei displaying both markers simultaneously (M&amp;T) were scored according to J.O. Gjørret et al. (2003 Biol. Reprod. 69. in press). Only M&amp;T nuclei were regarded as apoptotic, and +M, +T, and apoptotic (M&amp;T) indices (%) were calculated for the trophoblast (tb), inner cell mass (i) and the total blastocysts (t) in each group. Significant differences were observed for all parameters when all groups were compared (ANOVA, P ranging from 0.024 to&lt;0.0001). Highest number of total nuclei were observed in the S+ group, whereas the lowest indices were observed in the pp group, which had significant lower indices in the i and t than in the reg., S+ and S− groups P&lt;0.05; Tukey’s post test for ANOVA). Highest indices were generally observed in the S− group. The results demonstrate that not only embryo cell numbers but also incidences of apoptotic markers are affected by the mode of production. However, in Day 7 bovine blastocysts high cell number is not consistent with a low incidence of apoptosis. Even though cell numbers appeared comparable in the two in vivo groups, their incidences of apoptosis were different, and the reg group displayed indices comparable to the in vitro groups, highlighting the importance of ovulation protocols when in vivo embryos are used as reference material in general. Table 1


2021 ◽  
Author(s):  
Lydia K. Wooldridge ◽  
Alan D. Ealy

Abstract Previous work determined that bovine interleukin-6 (IL6) increases inner cell mass (ICM), primitive endoderm (PE) and total cell number in in vitro produced (IVP) bovine blastocysts. Another IL6 family member, leukemia inhibitory factor (LIF), has the potential to produce the same effects of IL6 due to the presence of its receptor in bovine blastocysts. We compared the abilities of LIF and IL6 to increase ICM cell numbers in day 7, 8 and 9 IVP bovine blastocysts. Supplementation with 100 ng/ml LIF from day 5 onward improved blastocyst formation rates on days 7 and 8 similar to what was observed when supplementing 100 ng/ml IL6. However, LIF supplementation did not cause an increase in ICM numbers like was observed after supplementing IL6. On day 9, increases in PE cell numbers were detected after LIF supplementation, but 300 ng/ml LIF was required to achieve the same effect on PE numbers that was observed by providing 100 ng/ml IL6. Collectively, these results show that LIF can mimic at least some of the effects of IL6 in bovine blastocyst.


2019 ◽  
Vol 97 (12) ◽  
pp. 4946-4950 ◽  
Author(s):  
Lydia K Wooldridge ◽  
Madison E Nardi ◽  
Alan D Ealy

Abstract Deficiencies in current embryo culture media likely contribute to the poor blastocyst development rates and pregnancy retention rates for in vitro produced (IVP) bovine embryos. Of special concern is the lack of micronutrients in these media formulations. One micronutrient of interest is zinc, an essential trace element involved with various enzyme and transcription factor activities. The objective of this work was to describe whether zinc sulfate supplementation during in vitro embryo culture affects bovine embryo development and blastomere numbers. Either 0, 2, 20, or 40 µM zinc sulfate was supplemented to presumptive zygotes cultured in synthetic oviductal fluid containing AAs and bovine serum albumin for 8 d. None of the treatments affected cleavage rates. Percentage of blastocysts on days 7 and 8 postfertilization was not affected by supplementing 2 or 20 µM zinc but were reduced (P &lt; 0.05) with 40 µM zinc. In blastocysts harvested on day 8, inner cell mass (ICM) and total cell number were increased (P &lt; 0.05) with 2 µM zinc supplementation but not with the other zinc concentrations. Numbers of trophectoderm cells were not affected by zinc treatment. In conclusion, supplementing zinc during bovine embryo culture did not impact blastocyst development but improved ICM cell numbers. This improvement in ICM cell number may have implications for improved pregnancy retention rates after IVP embryo transfer as smaller ICM sizes are associated with poor pregnancy success in cattle.


2012 ◽  
Vol 19 (3) ◽  
pp. 243-252 ◽  
Author(s):  
G. Giritharan ◽  
L. Delle Piane ◽  
A. Donjacour ◽  
F. J. Esteban ◽  
J. A. Horcajadas ◽  
...  

Reproduction ◽  
2019 ◽  
Vol 158 (4) ◽  
pp. 303-312 ◽  
Author(s):  
Lydia K Wooldridge ◽  
Sally E Johnson ◽  
Rebecca R Cockrum ◽  
Alan D Ealy

Supplementing interleukin-6 (IL6) to in vitro-produced bovine embryos increases inner cell mass (ICM) cell numbers in blastocysts. A series of studies were completed to further dissect this effect. Treatment with IL6 increased ICM cell numbers in early, regular and expanded blastocysts but had no effect on morulae total cell number. Treatment with IL6 for 30 min induced signal transducer and activator of transcription 3 (STAT3) phosphorylation and nuclear translocation in all blastomeres in early morulae and specifically within the ICM in blastocysts. Also, IL6 supplementation increased SOCS3 mRNA abundance, a STAT3-responsive gene, in blastocysts. Chemical inhibition of Janus kinase (JAK) activity from day 5 to day 8 prevented STAT3 activation and the IL6-induced ICM cell number increase. Global transcriptome analysis of blastocysts found that transcripts for IL6 and its receptor subunits (IL6R and IL6ST) were the most abundantly expressed IL6 family ligand and receptors. These results indicate that IL6 increases ICM cell numbers as the ICM lineage emerges at the early blastocyst stage through a STAT3-dependent mechanism. Also, IL6 appears to be the primary IL6 cytokine family member utilized by bovine blastocysts to control ICM cell numbers.


Zygote ◽  
2009 ◽  
Vol 17 (3) ◽  
pp. 209-215 ◽  
Author(s):  
Shuntaro Ikeda ◽  
Atsuhiro Tatemizo ◽  
Daisaku Iwamoto ◽  
Shunji Taniguchi ◽  
Yoichiro Hoshino ◽  
...  

SummaryHistone acetylation is one of the major mechanisms of epigenetic reprogramming of gamete genomes after fertilization to establish a totipotent state for normal development. In the present study, the effects of trichostatin A (TSA), an inhibitor of histone deacetylase, during in vitro fertilization (IVF) of bovine oocytes on subsequent embryonic development were investigated. Cumulus-enclosed oocytes obtained from slaughterhouse bovine ovaries were matured in vitro and subjected to IVF in a defined medium supplemented with 0 (control), 5, 50, and 500 nM TSA for 18 h. After IVF, presumptive zygotes were cultured in modified synthetic oviductal fluid (mSOF) medium until 168 h postinsemination (hpi). Some oocytes were immunostained using antibody specific for histone H4-acetylated lysine 5 at 10 hpi. Cleavage, blastocyst development and cell number of inner cell mass (ICM) and trophectoderm (TE) of blastocysts were assessed. TSA treatment enhanced histone acetylation that was prominent in decondensed sperm nuclei. TSA did not affect the postfertilization cleavage, blastocyst rates, and TE cell number. However, it significantly enhanced ICM cell number (p < 0.05). These results indicate that TSA treatment during IVF of bovine oocytes does not affect blastocyst development but alters the cell number of ICM, suggesting that overriding epigenetic modification of the genome during fertilization has a carryover effect on cell proliferation and differentiation in preimplantation embryos. Thus, further environmental quality controls in assisted reproductive technologies are needed in terms of factors which affect chromatin remodelling.


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