scholarly journals Identification and differential expression patterns of porcine OCT4 variants

Reproduction ◽  
2015 ◽  
Vol 149 (1) ◽  
pp. 55-66 ◽  
Author(s):  
Jae Yeon Hwang ◽  
Jong-Nam Oh ◽  
Dong-Kyung Lee ◽  
Kwang-Hwan Choi ◽  
Chi-Hun Park ◽  
...  

OCT4 encoded by POU5F1 has a crucial role of maintaining pluripotency in embryonic stem cells during early embryonic development and several OCT4 variants have been identified in mouse and human studies. The objective of this study was to identify different variants of OCT4 and analyze their expression patterns in preimplantation porcine embryos and various tissues. In this study, we showed that POU5F1 transcribes its three variants, namely OCT4A, OCT4B, and OCT4B1. The OCT4B transcript consists of exons identical to the major form of the OCT4 variant, OCT4A, with a differential N-terminal domain-coding exon. The structure of OCT4B1 mRNA was the same as that of OCT4B mRNA, but harbored a cryptic exon. Based on these findings, the transcription levels were investigated and found that OCT4B and OCT4B1 made up ∼20% among the variants in the embryonic stage and this indicates that OCT4A mRNA is dominantly expressed during preimplantation embryo development. In addition, OCT4B mRNA was detected in all tissues examined, while OCT4A and OCT4B1 were detected only in testis but not in other tissues examined. OCT4B1 showed inversely correlated expression with SOX2 and NANOG expression. OCT4A protein was specifically localized to the nuclei, whereas OCT4B was mainly localized to the cytoplasm of the porcine embryos at the blastocyst stage. The findings of this study reveal that the porcine OCT4 gene can potentially encode three variants (OCT4A, OCT4B, and OCT4B1), and they are differentially expressed and would have roles dissimilar between each other in preimplantation embryos and various adult tissues.

Reproduction ◽  
2013 ◽  
Vol 145 (4) ◽  
pp. 421-437 ◽  
Author(s):  
Pouneh Maraghechi ◽  
László Hiripi ◽  
Gábor Tóth ◽  
Babett Bontovics ◽  
Zsuzsanna Bősze ◽  
...  

MicroRNAs (miRNAs) are small non-coding RNAs that regulate multiple biological processes. Increasing experimental evidence implies an important regulatory role of miRNAs during embryonic development and in embryonic stem (ES) cell biology. In the current study, we have described and analyzed the expression profile of pluripotency-associated miRNAs in rabbit embryos and ES-like cells. The rabbit specific ocu-miR-302 and ocu-miR-290 clusters, and three homologs of the human C19MC cluster (ocu-miR-512, ocu-miR-520e, and ocu-miR-498) were identified in rabbit preimplantation embryos and ES-like cells. The ocu-miR-302 cluster was highly similar to its human homolog, while ocu-miR-290 revealed a low level of evolutionary conservation with its mouse homologous cluster. The expression of the ocu-miR-302 cluster began at the 3.5 days post-coitum early blastocyst stage and they stayed highly expressed in rabbit ES-like cells. In contrast, a high expression level of the ocu-miR-290 cluster was detected during preimplantation embryonic development, but a low level of expression was found in rabbit ES-like cells. Differential expression of the ocu-miR-302 cluster and ocu-miR-512 miRNA was detected in rabbit trophoblast and embryoblast. We also found that Lefty has two potential target sites in its 3′UTR for ocu-miR-302a and its expression level increased upon ocu-miR-302a inhibition. We suggest that the expression of the ocu-miR-302 cluster is characteristic of the rabbit ES-like cell, while the ocu-miR-290 cluster may play a crucial role during early embryonic development. This study presents the first identification, to our knowledge, of pluripotency-associated miRNAs in rabbit preimplantation embryos and ES-like cells, which can open up new avenues to investigate the regulatory function of ocu-miRNAs in embryonic development and stem cell biology.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Elo Madissoon ◽  
Eeva-Mari Jouhilahti ◽  
Liselotte Vesterlund ◽  
Virpi Töhönen ◽  
Kaarel Krjutškov ◽  
...  

Abstract PAIRED (PRD)-like homeobox genes belong to a class of predicted transcription factor genes. Several of these PRD-like homeobox genes have been predicted in silico from genomic sequence but until recently had no evidence of transcript expression. We found recently that nine PRD-like homeobox genes, ARGFX, CPHX1, CPHX2, DPRX, DUXA, DUXB, NOBOX, TPRX1 and TPRX2, were expressed in human preimplantation embryos. In the current study we characterized these PRD-like homeobox genes in depth and studied their functions as transcription factors. We cloned multiple transcript variants from human embryos and showed that the expression of these genes is specific to embryos and pluripotent stem cells. Overexpression of the genes in human embryonic stem cells confirmed their roles as transcription factors as either activators (CPHX1, CPHX2, ARGFX) or repressors (DPRX, DUXA, TPRX2) with distinct targets that could be explained by the amino acid sequence in homeodomain. Some PRD-like homeodomain transcription factors had high concordance of target genes and showed enrichment for both developmentally important gene sets and a 36 bp DNA recognition motif implicated in Embryo Genome Activation (EGA). Our data implicate a role for these previously uncharacterized PRD-like homeodomain proteins in the regulation of human embryo genome activation and preimplantation embryo development.


2020 ◽  
Author(s):  
Thomas W. Sheahan ◽  
Viktoria Major ◽  
Kimberly M. Webb ◽  
Elana Bryan ◽  
Philipp Voigt

AbstractThe closely related acetyltransferases CBP and p300 are key regulators of gene expression in metazoans. CBP/p300 acetylate several specific lysine residues within nucleosomes, including histone H3 lysine 27 (H3K27), a hallmark of active enhancers and promoters. However, it has remained largely unclear how specificity of CBP/p300 towards H3K27 is achieved. Here we show that the TAZ2 domain of CBP is required for efficient acetylation of H3K27, while curbing activity towards other lysine residues within nucleosomes. We find that TAZ2 is a sequence-independent DNA binding module, promoting interaction between CBP and nucleosomes, thereby enhancing enzymatic activity and regulating substrate specificity of CBP. TAZ2 is further required to stabilize CBP binding to chromatin in mouse embryonic stem cells, facilitating specificity towards H3K27 and modulating gene expression. These findings reveal a crucial role of TAZ2 in regulating H3K27ac, while highlighting the importance of correct site-specific acetylation for proper regulation of gene expression.


2013 ◽  
Vol 25 (8) ◽  
pp. 1174 ◽  
Author(s):  
Da-Peng Chu ◽  
Shi Tian ◽  
Da-Guang Sun ◽  
Chan-Juan Hao ◽  
Hong-Fei Xia ◽  
...  

Dibutyl phthalate (DBP), a widely used phthalate, is known to cause many serious diseases, especially in the reproductive system. However, little is known about the effects of its metabolite, mono-n-butyl phthalate (MBP), on preimplantation embryo development. In the present study, we found that treatment of embryos with 10–3 M MBP impaired developmental competency, whereas exposure to 10–4 M MBP delayed the progression of preimplantation embryos to the blastocyst stage. Furthermore, reactive oxygen species (ROS) levels in embryos were significantly increased following treatment with 10–3 M MBP. In addition, 10–3 M MBP increased apoptosis via the release of cytochrome c, whereas immunofluorescent analysis revealed that exposure of preimplantation embryos to MBP concentration-dependently (10–5, 10–4 and 10–3 M) decreased DNA methylation. Together, the results indicate a possible relationship between MBP exposure and developmental failure in preimplantation embryos.


Stem Cells ◽  
2006 ◽  
Vol 24 (12) ◽  
pp. 2685-2691 ◽  
Author(s):  
Greet Cauffman ◽  
Inge Liebaers ◽  
André Van Steirteghem ◽  
Hilde Van de Velde

Reproduction ◽  
2021 ◽  
Vol 161 (1) ◽  
pp. F41-F51
Author(s):  
Franchesca D Houghton

Development of the preimplantation embryo is reliant on nutrients present in the milieu of the reproductive tract. While carbohydrates, amino acids, lipids, and micronutrients are often considered when discussing preimplantation embryo nutrition, environmental oxygen is frequently overlooked. Although oxygen is not classically considered a nutrient, it is an important component of the in vitro culture environment and a critical regulator of cellular physiology. Oxygen is required to sustain an oxidative metabolism but when oxygen becomes limited, cells mount a physiological response driven by a family of transcription factors termed ‘hypoxia inducible factors’ which promote expression of a multitude of oxygen sensitive genes. It is this hypoxic response that is responsible not only for the switch to a glycolytic metabolism but also for a plethora of other cellular responses. There has been much debate in recent years over which environmental oxygen tension is preferential for the culture of preimplantation embryos. The review will evaluate this question and highlights how research using human embryonic stem cells can inform our understanding of why culturing under physiological oxygen tensions may be beneficial for the development of embryos generated through clinical in vitro fertilisation.


2014 ◽  
Vol 26 (3) ◽  
pp. 491 ◽  
Author(s):  
Da-Peng Chu ◽  
Shi Tian ◽  
Da-Guang Sun ◽  
Chan-Juan Hao ◽  
Hong-Fei Xia ◽  
...  

Dibutyl phthalate (DBP), a widely used phthalate, is known to cause many serious diseases, especially in the reproductive system. However, little is known about the effects of its metabolite, mono-n-butyl phthalate (MBP), on preimplantation embryo development. In the present study, we found that treatment of embryos with 10–3M MBP impaired developmental competency, whereas exposure to 10–4M MBP delayed the progression of preimplantation embryos to the blastocyst stage. Furthermore, reactive oxygen species (ROS) levels in embryos were significantly increased following treatment with 10–3M MBP. In addition, 10–3M MBP increased apoptosis via the release of cytochrome c, whereas immunofluorescent analysis revealed that exposure of preimplantation embryos to MBP concentration-dependently (10–5, 10–4 and 10–3M) decreased DNA methylation. Together, the results indicate a possible relationship between MBP exposure and developmental failure in preimplantation embryos.


2010 ◽  
Vol 22 (1) ◽  
pp. 350
Author(s):  
C. K. Lee ◽  
K. J. Uh ◽  
J. K. Park ◽  
H. S. Kim ◽  
H. M. Kim ◽  
...  

Porcine embryonic stem cells (ESC) can be a useful tool for the production of a transgenic animal and the study of developmental gene regulation. The study of porcine parthenogenetic ESC might also provide advantages in the understanding of changes in human parthenogenetic embryonic stem cells in the culture environment. Because human embryonic stem cells must be maintained stably for therapeutic uses, parthenogenetic porcine embryonic stem cells can give us precious information to help understand human parthenogenetic embryonic stem cells. Three putative porcine embryonic stem cell lines were derived from 99 parthenogenetic embryos. Cumulus-oocyte complexes were collected from prepubertal gilt ovaries and matured in vitro. Diploid parthenogenetic zygotes were produced by electrical activation followed by cytochalasin B treatment to suppress second polar body extrusion. Embryos were cultured to the blastocyst stage. Hatched blastocysts were directly cultured on mitomycin C-inactivated murine embryonic fibroblasts as feeder layers. Primary colonies were formed after 7 days of culture, and the colonies were transferred to new culture dishes 7 days after. They were passsaged every 5 days by physical dissociation, with one colony divided into small clumps and maintained for over 30 passages. These cells morphologically resembled human embryonic stem cells and consistently expressed the markers of pluripotent cells such as alkaline phosphatase, NANOG, OCT-4, SSEA-1, SSEA-4, TRA-1-60, and TRA-1-81. They could be maintained holding the previous characteristics after cryopreservation. Furthermore, we conducted experiments to confirm the expression patterns of the imprinted genes Igf2 and H19 in these ESC and IVF/parthenogenetic blastocysts using quantitative real-time PCR. At the blastocyst stage, the 2 genes were expressed in a parental-specific manner according to their origins in normal fertilized embryos and uniparental embryos. The putative parthenogenetic ESC, on the other hand, showed a high expression of Igf2, the paternally expressed gene, when compared with their blastocyst counterparts. Current work aims to confirm the authenticity of these ESC via teratoma formation in severe combined immunodeficiency mice following injection with these putative parthenogenetic ESC. This work was supported by the BioGreen 21 Program (#20070401034031, #20080401034031), Rural Development Administration, Republic of Korea (HK).


2014 ◽  
Vol 26 (8) ◽  
pp. 1166 ◽  
Author(s):  
Xian-Ju Huang ◽  
Xuguang Wang ◽  
Xueshan Ma ◽  
Shao-Chen Sun ◽  
Xiaolong Zhou ◽  
...  

Enhancer of zeste homologue 2 (Ezh2) is essential for the development of the early mouse preimplantation embryo. Loss of Ezh2 results in embryonic lethality in mice. Ezh2-deficient embryos display impaired outgrowth potential, defective establishment of Ezh2-null embryonic stem (ES) cells and adherence and differentiation of the trophoblast layer into giant cells. We investigated if Ezh2 controls the fate of embryos at an earlier stage by treating with cycloheximide (CHX) or microinjecting short interfering RNA (siRNA) to restrict embryonic Ezh2 expression during preimplantation. CHX inhibited de novo EZH2 protein synthesis in zygotes, suggesting that EZH2 requires de novo synthesis during post-fertilisation stages. We found that loss of Ezh2 at the pronuclear stage caused severe growth retardation and reduced blastocyst formation. Expression of the pluripotency-associated markers Oct4, Sox2 and Nanog were significantly decreased in embryos that had been injected with Ezh2 siRNA. In addition, Ezh2 loss induced upregulated expression of genes related to the differentiation of germ layers, including Gata6, Hoxb1 and Hand1. Finally, apoptosis was increased in the blastocyst embryos with Ezh2 knockdown. Modification of histone H3-Lysine 27 de-methylation and tri-methylation (H3K27me2/3) was strongly reduced in Ezh2 siRNA embryos. We conclude that Ezh2 is essential for early preimplantation embryo development through the regulation of epigenetic modification and apoptosis.


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