Mammalian fertilization begins with the fusion of two specialized gametes, followed by major epigenetic remodeling leading to the formation of a totipotent embryo. During the development of the pre-implantation embryo, precise reprogramming progress is a prerequisite for avoiding developmental defects or embryonic lethality, but the underlying molecular mechanisms remain elusive. For the past few years, unprecedented breakthroughs have been made in mapping the regulatory network of dynamic epigenomes during mammalian early embryo development, taking advantage of multiple advances and innovations in low-input genome-wide chromatin analysis technologies. The aim of this review is to highlight the most recent progress in understanding the mechanisms of epigenetic remodeling during early embryogenesis in mammals, including DNA methylation, histone modifications, chromatin accessibility and 3D chromatin organization.
Animals ; Chromatin Assembly and Disassembly ; DNA Methylation ; DNA Transposable Elements ; Embryo, Mammalian ; Embryonic Development/genetics* ; Epigenesis, Genetic ; Epigenome ; Female ; Fertilization/physiology* ; Gene Expression Regulation, Developmental ; Histone Code ; Histones/metabolism* ; Male ; Mice ; Oocytes/metabolism* ; Spermatozoa/metabolism*

Oligodendrocytes (OLs) are myelinating glial cells that form myelin sheaths around axons to ensure rapid and focal conduction of action potentials. Here, we found that an axonal outgrowth regulatory molecule, AATYK (apoptosis-associated tyrosine kinase), was up-regulated with OL differentiation and remyelination. We therefore studied its role in OL differentiation. The results showed that AATYK knockdown inhibited OL differentiation and the expression of myelin genes in vitro. Moreover, AATYK-deficiency maintained the proliferation status of OLs but did not affect their survival. Thus, AATYK is essential for the differentiation of OLs.
Animals ; Animals, Newborn ; Apoptosis Regulatory Proteins ; genetics ; metabolism ; Cell Differentiation ; drug effects ; physiology ; Cell Proliferation ; drug effects ; genetics ; Cells, Cultured ; Cuprizone ; toxicity ; Demyelinating Diseases ; chemically induced ; metabolism ; pathology ; Embryo, Mammalian ; Gene Expression Regulation, Developmental ; genetics ; Ki-67 Antigen ; metabolism ; Mice ; Mice, Inbred C57BL ; Myelin Basic Protein ; metabolism ; Myelin Proteolipid Protein ; metabolism ; Myelin Sheath ; drug effects ; metabolism ; Oligodendroglia ; drug effects ; metabolism ; Protein-Tyrosine Kinases ; genetics ; metabolism ; RNA, Small Interfering ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley

Heart is the first organ to function during mammalian embryogenesis. The differentiation of embryonic stem cells (ESCs) into cardiomyocyte is complex and dynamic, which involves 4 differentiation stages including ESCs, mesoderm, cardiac precursor, and terminal cardiomyocytes. Abnormal expression of certain genes can lead to congenital heart diseases during cardiomyocyte differentiation. Epigenetic regulation plays a crucial role on the switch of gene activation and deactivation during cardiomyocyte differentiation. Non-coding RNA, particularly microRNA and long non-coding RNA, may significantly influence gene expression. Exploring the regulatory roles of non-coding RNA in cardiomyocyte differentiation may contribute to the understanding of the functions of myocardial cells and mechanism of congenital heart diseases.
Animals ; Cell Differentiation ; genetics ; Embryo, Mammalian ; physiology ; Embryonic Stem Cells ; physiology ; Epigenesis, Genetic ; genetics ; Humans ; Myocytes, Cardiac ; physiology ; RNA, Long Noncoding ; genetics

Axonal transport of mitochondria is critical for neuronal survival and function. Automatically quantifying and analyzing mitochondrial movement in a large quantity remain challenging. Here, we report an efficient method for imaging and quantifying axonal mitochondrial transport using microfluidic-chamber-cultured neurons together with a newly developed analysis package named "MitoQuant". This tool-kit consists of an automated program for tracking mitochondrial movement inside live neuronal axons and a transient-velocity analysis program for analyzing dynamic movement patterns of mitochondria. Using this method, we examined axonal mitochondrial movement both in cultured mammalian neurons and in motor neuron axons of Drosophila in vivo. In 3 different paradigms (temperature changes, drug treatment and genetic manipulation) that affect mitochondria, we have shown that this new method is highly efficient and sensitive for detecting changes in mitochondrial movement. The method significantly enhanced our ability to quantitatively analyze axonal mitochondrial movement and allowed us to detect dynamic changes in axonal mitochondrial transport that were not detected by traditional kymographic analyses.
Animals ; Axonal Transport ; physiology ; Cerebral Cortex ; cytology ; metabolism ; Drosophila melanogaster ; cytology ; metabolism ; Embryo, Mammalian ; Gene Expression ; Lab-On-A-Chip Devices ; Microscopy, Confocal ; Mitochondria ; metabolism ; ultrastructure ; Motor Neurons ; metabolism ; ultrastructure ; Movement ; Mutation ; Primary Cell Culture ; RNA-Binding Protein FUS ; genetics ; metabolism ; Rats ; Rats, Sprague-Dawley ; Software

OBJECTIVETo observe the regulatory effects of psoralen, oleanolic acid, and stilbene glucoside, three active components of psoralea fruit, glossy privet fruit and tuber fleeceflower root respectively, on Aβ25-35induced self-renewal and neuron-like differentiation of neural stem cells (NSCs).

METHODSEmbryonic NSCs werein vitro isolated and cultured from Kunming mice of 14-day pregnancy, and randomly divided into the control group, the Aβ25-35 group, the Aβ25-35 +psoralen group, the Aβ25-35 +oleanolic acid group, and the Aβ25-35 + stilbene glucoside group. The intervention concentration of Aβ25-35 was 25 µmol/L, and the intervention concentration of three active components of Chinese medicine was 10(-7)mol/L. The effect of three active components of Chinese medicine on the proliferation of NSCs was observed by counting method. The protein expression of Tubulin was observed by Western blot and immunofluorescence. The ratio of Tubulin+/DAPI was caculated. Results Compared with the control group, the sperical morphology of NSCs was destroyed in the Aβ25-35 group, the counting of NSCs, the expression of Tubulin protein, and the ratio of Tubulin /DAPI all decreased (P <0.01, P <0.05). Compared with the Aβ25-35 group, the counting of NSCs, the expression of Tubulin protein, and the ratio of Tubulin + /DAPI all increased in the three Chinese medicine treated groups (P <0. 01, P <0. 05).

CONCLUSIONS25 µmol/L Aβ25-35 could inhibit self-renewal and neuron-like differentiating of NSCs. But psoralen, oleanolic acid, and stilbene glucoside could promote self-renewal of NSCs and neuron-like differentiation.

Amyloid beta-Peptides ; physiology ; Animals ; Cell Differentiation ; drug effects ; Cell Proliferation ; drug effects ; Cells, Cultured ; Drugs, Chinese Herbal ; pharmacology ; Embryo, Mammalian ; Female ; Mice ; Neural Stem Cells ; Neurogenesis ; drug effects ; Neurons ; cytology ; Peptide Fragments ; physiology ; Pregnancy

Histone methylation is one of the most widely studied post-transcriptional modifications. It is thought to be an important epigenetic event that is closely associated with cell fate determination and differentiation. To explore the spatiotemporal expression of histone H3 lysine 4 trimethylation (H3K4me3) and histone H3 lysine 27 trimethylation (H3K27me3) epigenetic marks and methylation or demethylation transferases in tooth organ development, we measured the expression of SET7, EZH2, KDM5B and JMJD3 via immunohistochemistry and quantitative polymerase chain reaction (qPCR) analysis in the first molar of BALB/c mice embryos at E13.5, E15.5, E17.5, P0 and P3, respectively. We also measured the expression of H3K4me3 and H3K27me3 with immunofluorescence staining. During murine tooth germ development, methylation or demethylation transferases were expressed in a spatial-temporal manner. The bivalent modification characterized by H3K4me3 and H3K27me3 can be found during the tooth germ development, as shown by immunofluorescence. The expression of SET7, EZH2 as methylation transferases and KDM5B and JMJD3 as demethylation transferases indicated accordingly with the expression of H3K4me3 and H3K27me3 respectively to some extent. The bivalent histone may play a critical role in tooth organ development via the regulation of cell differentiation.
Animals ; Cell Differentiation ; physiology ; DNA-Binding Proteins ; analysis ; Dental Papilla ; embryology ; Embryo, Mammalian ; Enamel Organ ; embryology ; Enhancer of Zeste Homolog 2 Protein ; Epigenesis, Genetic ; physiology ; Gene Expression Regulation, Developmental ; Histone-Lysine N-Methyltransferase ; analysis ; Histones ; metabolism ; Jumonji Domain-Containing Histone Demethylases ; analysis ; Lysine ; metabolism ; Methylation ; Mice ; Mice, Inbred BALB C ; Odontogenesis ; physiology ; Polycomb Repressive Complex 2 ; analysis ; Protein Processing, Post-Translational ; physiology ; Tooth Germ ; embryology

The level of P4 at the time of embryo transfer (ET) is important. P4 concentrations and numbers of corpora lutea for 126 recipients were evaluated. Nuclear transfer embryos were transferred into 126 surrogates. 11 maintained their pregnancy until full-term delivery, 17 miscarried, and implantation failed in 98 animals. P4 levels in the full-term group were significantly different from those of the pigs that aborted or in which implantation failed (p < 0.05). However, the numbers of corpora lutea were not significantly different. These findings indicate that the concentration of progesterone can be an important factor for successful ET in pigs.
Animals ; Corpus Luteum/*physiology ; Embryo Transfer/*veterinary ; Embryo, Mammalian/*physiology ; Female ; Nuclear Transfer Techniques ; Pregnancy ; *Pregnancy Rate ; Progesterone/*blood ; Retrospective Studies ; Sus scrofa/*physiology

This study was conducted to establish an in vitro maturation (IVM) system by selection of efficient porcine serum during porcine in vitro production. To investigate the efficient porcine serum (PS), different types of PS [newborn pig serum, prepubertal gilt serum (PGS), estrus sow serum, and pregnancy sow serum] were used to supplement IVM media with or without gonadotrophin (GTH) and development rates of parthenogenetic activation (PA) and in vitro fertilization (IVF) embryos were then compared. The maturation rates of the PGS group was significantly higher when GTH was not added. Additionally, during development of PA embryos without GTH, the PGS group showed significantly higher cleavage and blastocyst formation rates. Moreover, the cleavage rates of IVF embryos were significantly higher in the PGS group, with no significant differences in the blastocyst formation. However, when GTH was supplemented into the IVM media, there were no significant differences among the four groups in the cleavage rates, development rates of the blastocyst, and cell number of the blastocyst after PA and IVF. In conclusion, PGS is an efficient macromolecule in porcine IVM, and GTH supplementation of the IVM media is beneficial when PS is used as macromolecule, regardless of its origin.
Animals ; Blastocyst/*drug effects ; Embryo, Mammalian/drug effects/*embryology/physiology/ultrastructure ; Fertilization in Vitro/veterinary ; Gonadotropins/administration & dosage/*metabolism ; In Vitro Oocyte Maturation Techniques/*methods/veterinary ; Parthenogenesis/*drug effects ; Sus scrofa/*embryology

OBJECTIVETo investigate the fetotoxicity of monocrotaline.

METHODMouse whole embryo culture (WEC) was applied. Post-implantation (8.5 d) mouse embryos were isolated from their mothers and put into the medium of immediately centrifuged serum (ICS) prepared from rats. Different concentrations of monocrotaline (100, 50, 25, 12.5 mg x L(-1)) were added into the WEC. Development (yolk sac diameter, crown-rump length, head length, somite number) and organic morphodifferentiation (yolk sac circulation, allantois, embryonic flexion, heart, brain, optic-otic-olfactory organ, branchial arch, maxillary, mandible, bud) of embryos were observed at 48 h after treatment.

RESULTObvious fetotoxicity could be observed in various monocrotaline treatment groups in a dose-dependent manner. Development of embryos was delayed significantly at dose 12.5-100 mg x L(-1). Malformations were shown in all organic morphodifferentiation indice, especially in opti-otic organ, mandible and bud.

CONCLUSIONMonocrotaline had obvious fetotoxicity in vitro WEC, indicating that exposure of pregnant mice to monocrotaline may have potential risk on fetus.

Animals ; Cell Differentiation ; drug effects ; Culture Media ; Embryo, Mammalian ; drug effects ; physiology ; Female ; Male ; Mice ; Monocrotaline ; toxicity

BACKGROUNDHigh microvascular permeability plays an essential role in pathological process of multiple diseases such as septic shock, acute lung injury and acute respiratory distress syndrome, and burns. Inhibiting hyperpermeability is significant for controlling these conditions. Cdc42, as a main member of the small Rho GTPase family, plays a critical role in controlling and regulating the endothelial junctional permeability. We aimed to generate and identify endothelial specific cdc42-deficient mice by the Cre/loxp recombination approach, for examination in an animal model of the contribution of the cdc42 gene in the microvascular barrier function.

METHODSWe crossed cdc42(Flox/Flox) mice with mice expressing endothelial cell-specific Cre recombinase, and the offspring with the genotype cdc42(Flox/+)Tie2Cre(+/-) were back-crossed with the cdc42(Flox/Flox) mice. The cdc42(Flox/Flox)Tie2Cre(+/-) mice in the F2 generation were the target mice. If the cdc42 deficient mice did not survive, we would observe the cdc42 deficient mice embryos, and compare them with wild-type mice embryos.

RESULTSCdc42(flox/+)Cre(+/-) mice were mated with the cdc42(Flox/Flox) mice and among the living offspring there were no cdc42(Flox/Flox)Cre(+/-) target mice. We found the endothelial special cdc42 deficient embryos at the E7.5-E16.5 stage. We observed that cdc42 deficient embryos were much smaller, had fewer vessels and were a little more swollen compared with the wild-type embryos.

CONCLUSIONSEndothelial specific knockout of cdc42 caused embryonic lethality and the mice did not survive to birth. The target embryos were much smaller, had fewer vessels and were a little more swollen compared with the wild-type embryos. These results demonstrated that the cdc42 plays an important role in development of embryos and in development of microvessels as well as microvascular permeability.

Animals ; Embryo, Mammalian ; blood supply ; metabolism ; Endothelium, Vascular ; embryology ; metabolism ; Female ; Immunohistochemistry ; Male ; Mice ; Mice, Inbred C57BL ; Mice, Knockout ; Neovascularization, Physiologic ; genetics ; physiology ; cdc42 GTP-Binding Protein ; genetics ; metabolism