scholarly journals Maternal parity affects Day 8 embryo gene expression in old mares

2021 ◽  
Author(s):  
Emilie Derisoud ◽  
Luc Jouneau ◽  
Clothilde Gourtay ◽  
Anne Margat ◽  
Catherine Archilla ◽  
...  

As sport career is a priority in most of equine breeds, mares are frequently bred for the first time at an advanced age. Both age and first gestation were shown to have a deleterious effect on reproduction outcomes, respectively on fertility and offspring weight but the effect mare's parity in older mares on embryo quality has never been considered. The aim of this project was to determine the effect of old mare's nulliparity on gene expression in embryos. Day 8 post ovulation embryos were collected from old (10-16 years old) nulliparous (ON, N=5) or multiparous (OM, N=6) non-nursing Saddlebred mares, inseminated with the semen of one stallion. Pure (TE_part) or inner cell mass enriched (ICMandTE) trophoblast were obtained by embryo bisection and paired end, non-oriented RNA sequencing (Illumina, NextSeq500) was performed on each hemi-embryo. To discriminate gene expression in the ICM from that in the TE, deconvolution (DeMixT R package) was used on the ICMandTE dataset. Differential expression was analyzed (DESeq2) with embryo sex and diameter as cofactors using a false discovery rate <0.05 cutoff. Although the expression of only a few genes was altered by mare's nulliparity (33 in ICM and 23 in TE), those genes were related to nutrient exchanges and responses to environment signaling, both in ICM and TE, suggesting that the developing environment from these mares are not optimal for embryo growth. In conclusion, being nulliparous and old does not seem to be the perfect match for embryonic development in mares.

1993 ◽  
Vol 13 (12) ◽  
pp. 7971-7976
Author(s):  
L M Whyatt ◽  
A Düwel ◽  
A G Smith ◽  
P D Rathjen

Embryonic stem (ES) cells, derived from the inner cell mass of the preimplantation mouse embryo, are used increasingly as an experimental tool for the investigation of early mammalian development. The differentiation of these cells in vitro can be used as an assay for factors that regulate early developmental decisions in the embryo, while the effects of altered gene expression during early embryogenesis can be analyzed in chimeric mice generated from modified ES cells. The experimental versatility of ES cells would be significantly increased by the development of systems which allow precise control of heterologous gene expression. In this paper, we report that ES cells are responsive to alpha and beta interferons (IFNs). This property has been exploited for the development of inducible ES cell expression vectors, using the promoter of the human IFN-inducible gene, 6-16. The properties of these vectors have been analyzed in both transiently and stably transfected ES cells. Expression was minimal or absent in unstimulated ES cells, could be stimulated up to 100-fold by treatment of the cells with IFN, and increased in linear fashion with increasing levels of IFN. High levels of induced expression were maintained for extended periods of time in the continuous presence of the inducing signal or following a 12-h pulse with IFN. Treatment of ES cells with IFN did not affect their growth or differentiation in vitro or compromise their developmental potential. This combination of features makes the 6-16-based expression vectors suitable for the functional analysis of developmental control control genes in ES cells.


eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Eszter Posfai ◽  
Sophie Petropoulos ◽  
Flavia Regina Oliveira de Barros ◽  
John Paul Schell ◽  
Igor Jurisica ◽  
...  

The segregation of the trophectoderm (TE) from the inner cell mass (ICM) in the mouse blastocyst is determined by position-dependent Hippo signaling. However, the window of responsiveness to Hippo signaling, the exact timing of lineage commitment and the overall relationship between cell commitment and global gene expression changes are still unclear. Single-cell RNA sequencing during lineage segregation revealed that the TE transcriptional profile stabilizes earlier than the ICM and prior to blastocyst formation. Using quantitative Cdx2-eGFP expression as a readout of Hippo signaling activity, we assessed the experimental potential of individual blastomeres based on their level of Cdx2-eGFP expression and correlated potential with gene expression dynamics. We find that TE specification and commitment coincide and occur at the time of transcriptional stabilization, whereas ICM cells still retain the ability to regenerate TE up to the early blastocyst stage. Plasticity of both lineages is coincident with their window of sensitivity to Hippo signaling.


2020 ◽  
Vol 21 (18) ◽  
pp. 6488
Author(s):  
Arkadiusz Kajdasz ◽  
Ewelina Warzych ◽  
Natalia Derebecka ◽  
Zofia E. Madeja ◽  
Dorota Lechniak ◽  
...  

Compared to other mammalian species, porcine oocytes and embryos are characterized by large amounts of lipids stored mainly in the form of droplets in the cytoplasm. The amount and the morphology of lipid droplets (LD) change throughout the preimplantation development, however, relatively little is known about expression of genes involved in lipid metabolism of early embryos. We compared porcine and bovine blastocyst stage embryos as well as dissected inner cell mass (ICM) and trophoblast (TE) cell populations with regard to lipid droplet storage and expression of genes functionally annotated to selected lipid gene ontology terms using RNA-seq. Comparing the number and the volume occupied by LD between bovine and porcine blastocysts, we have found significant differences both at the level of single embryo and a single blastomere. Aside from different lipid content, we found that embryos regulate the lipid metabolism differentially at the gene expression level. Out of 125 genes, we found 73 to be differentially expressed between entire porcine and bovine blastocyst, and 36 and 51 to be divergent between ICM and TE cell lines. We noticed significant involvement of cholesterol and ganglioside metabolism in preimplantation embryos, as well as a possible shift towards glucose, rather than pyruvate dependence in bovine embryos. A number of genes like DGAT1, CD36 or NR1H3 may serve as lipid associated markers indicating distinct regulatory mechanisms, while upregulated PLIN2, APOA1, SOAT1 indicate significant function during blastocyst formation and cell differentiation in both models.


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.


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


2011 ◽  
Vol 23 (1) ◽  
pp. 194
Author(s):  
M. Filliers ◽  
W. de Spiegelaere ◽  
L. J. Peelman ◽  
K. Goossens ◽  
C. Burvenich ◽  
...  

Isolation of pure inner cell mass (ICM) and trophoblast samples from a single blastocyst is necessary to obtain accurate information on the transcriptome of these cells. Microsurgical techniques have been described to separate the ICM and trophoblast, but unfortunately, contamination of the ICM cell population with trophoblastic cells is inevitable with these methods. Alternatively, immunosurgery has been described as a valuable technique to obtain a pure ICM sample, although this technique seems to alter the normal gene expression pattern. Laser capture microdissection (LCM) provides the possibility of isolating small tissue fractions from heterogeneous tissue sections, without contamination by the surrounding tissue and without changing the gene expression pattern of the cells. In this study, a protocol is described for the application of LCM to isolate homogeneous ICM and trophoblast samples from single bovine blastocysts for downstream gene expression analysis. The absence of contaminating trophoblastic fractions in the isolated ICM cells was controlled with primers for the keratin 18 (KRT18) gene, which is considered a trophoblast-specific marker in bovine blastocysts. Expanded blastocysts were produced by routine in vitro methods described by (Vandaele et al. 2010 Reproduction 139, 505–511) and fixed in a modified methacarn solution for 24 h. After fixation, the blastocysts were embedded in RNase-free soluble agarose 2%, processed in an STP 420D Tissue Processor, embedded in paraffin, cut in serial sections, and adhered to glass slides, followed by deparaffinization in xylene and staining of the sections with 0.1% cresyl violet in a 85% ethanol solution. Laser capture microdissection was performed as described previously by (De Spiegelaere et al. 2008 Anal. Biochem. 382, 72–74). The ICM was isolated by placing the same cap over 3 to 4 serial sections of one blastocyst. Subsequently, the same procedure was performed with a second cap to isolate the trophoblast. Total RNA was isolated from the LCM-derived ICM and trophoblast on the caps and converted into cDNA. Gene-specific primers for KRT18 (5′-GCAGACCGCTGAGATAGGA-3′ and 5′-GCATATCGGGCCTCCACTT-3′) and for 18S rRNA, a commonly used reference gene (5′-AGAAACGGCTACCACATCCA-3′ and 5′-CACCAGACTTGCCCTCCA-3′), were used and PCR was carried out. Expression of the control gene 18S rRNA was readily detectable in all cell samples. Keratin 18 was detectable in LCM-derived trophoblast, but was absent in the LCM-derived ICM cells, indicative of the successful isolation of ICM cells without contaminating trophoblastic cells. This study demonstrates a novel approach for the application of LCM on small tissue samples that are difficult to handle and which can be used for molecular analysis of specific cell lineages within embryos of different species. Supported by the Fund for Scientific Research–Flanders, Belgium, aspirant 1.1.477.07N00.


2010 ◽  
Vol 22 (1) ◽  
pp. 279
Author(s):  
S. C. Isom ◽  
R. S. Prather

Traditional microarray approaches to gene expression profiling often require RNA or cDNA amplification when working with extremely small or valuable tissue samples.This process is generally viewed as being undesirable because there is potential for bias to be introduced during amplification. Very recently, the so-called next-generation sequencing technologies were adapted for use in global gene expression profiling. Herein we report our efforts to apply these sequencing technologies to assess relative transcript abundances in pre-implantation-stage porcine embryos, without additional nucleic acid amplification before sequencing. As a proof-of-principle experiment, we have isolated total RNA from the embryonic disc (inner cell mass; ICM) and a small piece of trophectoderm (TE) from a Day 12 in vivo-produced embryo, which were estimated to be composed of 500 to 1000 cells each. The RNA was reverse transcribed using oligo-dT priming followed by second-strand cDNA synthesis. The double-stranded cDNA was then randomly sheared by sonication, and 10 ng of double-stranded cDNA fragments was used for sample preparation before sequencing. Prepared cDNA fragments (at 7 picomolar concentrations) were submitted for sequencing using the Illumina/Solexa platform as recommended. The millions of short (36 bp) reads generated by Illumina sequencing for each sample were then aligned to the swine UniGene database from NCBI, allowing for zero or one mismatches. Relative transcript abundances between cell types were profiled by considering the read counts for a given UniGene member as a percentage of the total number of reads generated for each cell type. It was demonstrated that approximately 11 000 and 9000 UniGene members were represented by a normalized average of 5 or more short reads per lane (0.001% of the total) in the ICM and TE samples, respectively. As expected, pluripotency factors, chromatin remodeling components, and cell-cell communication molecules were overrepresented in the ICM sample as compared with the TE sample. Conversely, epithelial determinants, ion transporters, and components of the steroid biosynthesis pathways were more abundant in the TE sample than in the ICM sample. Relative abundances of representative transcripts in these samples were verified by quantitative RT-PCR. In conclusion, we demonstrate the utility of next-generation sequencing technologies for gene expression profiling using even minute tissue samples and show that such analyses are possible even in species without a sequenced genome.


2013 ◽  
Vol 25 (1) ◽  
pp. 226 ◽  
Author(s):  
E. P. López-Damián ◽  
T. Fiordelisio ◽  
M. A. Lammoglia ◽  
M. Alarcón ◽  
M. Asprón ◽  
...  

Accurate evaluation of bovine embryos for assessing developmental stage and quality is critical to the success of any embryo transfer program. However, this evaluation process has been reported to be highly subjective in Bos indicus (BI) and can vary as much as 23% compared with that of Bos taurus (BT). These differences in assessment may be related to the quantity of lipid droplets (LD) within the embryo, which has been shown to have a negative effect in cryopreserving embryos. The aim of the present study was to characterize the number and size of LD in different developmental stages of fresh embryos from BI and BT and to compare LD across the three different embryo quality grades (1 = excellent or good, 2 = fair, and 3 = poor). Nonsurgical embryo collection was performed 7 days post-insemination in 10 BI and 10 BT females. Forty-eight embryos were evaluated for stage and grade using stereoscopic microscopy, processed for transmission electron microscopy, and stained with Nile red. Digitalized images were analyzed with ImageJ (National Institutes of Health, Bethesda, MD, USA), contour of lipid droplets were designed, and values of perimeter, area, and fluorescence intensity were assessed. Nonparametric statistical analysis (Mann–Whitney) was utilized. There was no difference in LD number for BT or BI for morulae and blastocyst; however, BI morulae presented larger LD compared with blastocyst stage embryos (286 µm2 v. 223 µm2; P < 0.05). Likewise, BI TF cells had more LD compared with inner cell mass (ICM) cells (48 v. 36; P < 0.05). BT TF cells exhibited larger LD compared with ICM cells (149 µm2 v. 128 µm2; P < 0.05), while BI embryos exhibited a larger area of LD in the ICM compared with the TF (591 µm2 v. 472 µm2; P < 0.05). In all embryos, BI contained more lipid droplets than BT (78 v. 49; P < 0.05). Across all quality grades (good, fair, and poor) there was no difference in the number of LD in BT embryos; however, BI grade-3 embryos presented more LD than grade-1 (36 v. 25). BT embryos LD were larger than BI LD (907 µm2 v. 625 µm2; P < 0.05). Fluorescence images showed higher arbitrary units of fluorescence (auf) for LD in BI. Compared with BT embryos (386 auf v. 280 auf; P < 0.05). These results suggest that BI embryos contain more and smaller LD than BT embryos and the LD described for BI embryo quality grade 1 are larger than those of quality grades 2 and 3, and even though the number of LD in morulae and blastocyst stage embryos are not different LD size is reduced as development occurs. Research funding provided by UNAM-DGAPA-PAPIIT IN200810.


2006 ◽  
Vol 18 (5) ◽  
pp. 551 ◽  
Author(s):  
Michael Hoelker ◽  
Friedrich Schmoll ◽  
Hendrik Schneider ◽  
Franca Rings ◽  
Markus Gilles ◽  
...  

The aim of the present study was to explore whether the blastocyst diameter and the zona thickness at 168 h after fertilisation are useful parameters to predict quality and viability of bovine in-vitro-produced (IVP)-embryos. Although significant (P < 0.05), the blastocyst diameter at 168 h correlated only poorly with the total number of cells (R2 = 0.13) and with the number of trophectoderm (TE) cells (R2 = 0.17). Hatched blastocysts (n = 66) at 216 h had a significantly greater mean diameter at 168 h (194.8 ± 16.8 µm) compared with either blastocysts that had started but not finished hatching at 216 h (n = 26, 178.4 ± 16.7 µm) or failed to commence hatching (n = 136, 162.7 ± 12.9 µm). Transfer of 101 IVP blastocysts to synchronised recipients resulted in the birth of 38 calves (38%). There were significantly more bull calves born than cow calves (P < 0.05), but this was not correlated with blastocyst diameter or zona thickness at 168 h. There was also no correlation between the diameter of blastocysts or the zona thickness at 168 h and parameters of subsequent developmental characteristics, including rates of pregnancy, resorptions and abortions, pregnancy duration, delivery to term and birthweight. Overall, the present results indicate that the blastocyst diameter and the zona thickness at 168 h are good predictors for subsequent hatching ability in vitro, but not for the number of TE cells, inner cell mass cells or total cells and neither for subsequent developmental characteristics after transfer to recipients.


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