Protein kinase C (PKC) is a critical molecule in cellular signal transduction in mammals. It is involved in many biological processes in embryonic development, including nuclear remodeling, cell cycle adjustment and cellular polarity regulation. The present study aimed to observe the location of PKCα, an important isozyme of PKC, in fertilized, parthenogenetic and tetraploid preimplantation embryos, and compare the expression of PKCα during embryonic compaction in Kunming mice. The location of PKCα was detected by immunochemistry and laser confocal microscopy. Western blot was performed to quantify PKCα expression during embryonic compaction in the three kinds of embryos. In the experiment, fertilized embryos were flushed from oviduct or uterus at 45, 52, 69, 76 and 93 h after injection of human chorionic gonadotrophin (hCG); parthenogenetic embryos were collected by SrCl2 activation of oocytes for 6 h; and tetraploid embryos were produced by electrofusion of 2-cell embryos. Embryos were fixed at different developmental stages for immunofluorescent staining. 8-cell/4-cell embryos and morula were lysed for Western blot. The results showed that PKCα had similar location pattern in different embryos. It was distributed mainly in the nuclear aggregating around chromatin at different developmental stages. However, PKCα expressed strongly in the interphase than in mitotic blastomere. Before embryonic compaction, PKCα was localized at the blastomere boundary. At late blastocyst stage of fertilized embryos, PKCα was localized only in the polar trophoblast, but not in other trophoblast. At late stage of pathenogenetic blastocyst, there was no clear PKCα signal in the polar trophoblast. Tetraploid embryos had larger blastomere than other embryos and compacted after 4-cell stage, but not after 8-cell stage. Meanwhile, there was PKCα signal at the blastomere boundary at 4-cell stage. Our results showed that the expression of PKCα lasted through all the preimplantation stage. Although there were different expression levels among different stages, the expression increased around embryonic compaction. Quantification of expression of PKCα by Western blot demonstrated that the expression increased after compaction, indicating that the compaction was possibly dependent on the relocation of PKCα. Moreover, it was shown that the second relocation of PKCα occurred during the blastocyst formation. PKCα had different expression patterns in the three kinds of preimplantation embryos. However, the effects of PKCα on embryonic development started in early stage. There must be a necessary connection between PKCα relocation and cell adhesion starting at embryonic compaction.
Animals ; Embryonic Development ; Female ; Mice ; Parthenogenesis ; Pregnancy ; Protein Kinase C-alpha ; metabolism ; Tetraploidy ; Trophoblasts ; enzymology

Human embryonic stem cells can be induced to differentiate into all kinds of cells in vitro to be applied to clinical medicine and scientific research. Because they have to be isolated from human embryos, any attempt to establish human stem cell line is prohibited by religion and ethics in some areas and countries. Parthogenetic embryonic stem cells have similar capacity of totipotency and proliferation, and can be established from parthenogenetic activation of discarded oocytes. This paper reviews the progress in the studies of the establishment of parthenogenetic embryonic stem cell line and its differentiation capacities.
Animals ; Cell Differentiation ; Embryo, Mammalian ; cytology ; Humans ; Parthenogenesis ; Stem Cell Transplantation ; Stem Cells ; cytology

Parthenogenetic embryonic stem (pES) cells isolated from parthenogenetic activation of oocytes and embryos, also called parthenogenetically induced pluripotent stem cells, exhibit pluripotency evidenced by both in vitro and in vivo differentiation potential. Differential proteomic analysis was performed using differential in-gel electrophoresis and isotope-coded affinity tag-based quantitative proteomics to investigate the molecular mechanisms underlying the developmental pluripotency of pES cells and to compare the protein expression of pES cells generated from either the in vivo-matured ovulated (IVO) oocytes or from the in vitro-matured (IVM) oocytes with that of fertilized embryonic stem (fES) cells derived from fertilized embryos. A total of 76 proteins were upregulated and 16 proteins were downregulated in the IVM pES cells, whereas 91 proteins were upregulated and 9 were downregulated in the IVO pES cells based on a minimal 1.5-fold change as the cutoff value. No distinct pathways were found in the differentially expressed proteins except for those involved in metabolism and physiological processes. Notably, no differences were found in the protein expression of imprinted genes between the pES and fES cells, suggesting that genomic imprinting can be corrected in the pES cells at least at the early passages. The germline competent IVM pES cells may be applicable for germ cell renewal in aging ovaries if oocytes are retrieved at a younger age.
Animals ; Cell Line ; Electrophoresis, Gel, Two-Dimensional ; Mice ; Parthenogenesis ; physiology ; Pluripotent Stem Cells ; metabolism ; Proteomics ; methods

Parthenogenetic embryos, created by activation and diploidization of oocytes, arrest at mid-gestation for defective paternal imprints, which impair placental development. Also, viable offspring has not been obtained without genetic manipulation from parthenogenetic embryonic stem cells (pESCs) derived from parthenogenetic embryos, presumably attributable to their aberrant imprinting. We show that an unlimited number of oocytes can be derived from pESCs and produce healthy offspring. Moreover, normal expression of imprinted genes is found in the germ cells and the mice. pESCs exhibited imprinting consistent with exclusively maternal lineage, and higher X-chromosome activation compared to female ESCs derived from the same mouse genetic background. pESCs differentiated into primordial germ cell-like cells (PGCLCs) and formed oocytes following in vivo transplantation into kidney capsule that produced fertile pups and reconstituted ovarian endocrine function. The transcriptome and methylation of imprinted and X-linked genes in pESC-PGCLCs closely resembled those of in vivo produced PGCs, consistent with efficient reprogramming of methylation and genomic imprinting. These results demonstrate that amplification of germ cells through parthenogenesis faithfully maintains maternal imprinting, offering a promising route for deriving functional oocytes and having potential in rebuilding ovarian endocrine function.
Animals ; Female ; Mice ; Mice, Transgenic ; Mouse Embryonic Stem Cells/metabolism* ; Oocytes/metabolism* ; Parthenogenesis

Identification of the function of all genes in the mammalian genome is critical in understanding basic mechanisms of biology. However, the diploidy of mammalian somatic cells has greatly hindered efforts to elucidate the gene function in numerous biological processes by mutagenesis-based genetic approaches. Recently, mouse haploid embryonic stem (haES) cells have been successfully isolated from parthenogenetic and androgenetic embryos, providing an ideal tool for genetic analyses. In these studies, mouse haES cells have already shown that they could be used in cell-based forward or reverse genetic screenings and in generating gene-targeting via homologous recombination. In particular, haES cells from androgenetic embryos can be employed as novel, renewable form of fertilization agent for yielding live-born mice via injection into oocytes, thus showing the possibility that genetic analysis can be extended from cellular level to organism level.
Animals ; Embryonic Stem Cells ; cytology ; metabolism ; Genetic Techniques ; Genome ; Haploidy ; Models, Animal ; Mutagenesis ; Parthenogenesis

Tubulin is the major protein of microtubule. alpha- and beta- tubulins form heterodimers, while gamma-tubulin regulates microtubule organization. The present study aimed to observe the dynamic changes of gamma-tubulin in preimplantation development of parthenogenetic mouse embryos. Immunofluorescence and laser confocal microscopy were used to detect the location of gamma-tubulin in preimplantation parthenogenetic embryos activated by SrCl2. The oocytes were collected at 13-14 h after hCG injection, and then activated with 10 mmol/L SrCl2 in Ca(2+)-free CZB medium with 5 mmol/L cytochalasin B (CB), fixed at 1 h intervals until 6 h after activation. The results showed that spindle was paralleled with the cell membrane all the time, when the meiosis of MII mouse oocytes resumed. The rotation of spindle was inhibited, but karyokinesis was not influenced. At 0 h after activation, i.e. at metaphase, gamma-tubulin was distributed mainly on the two poles of spindle. At 1 h after activation, i.e. at anaphase, following the separation of chromosomes, gamma-tubulin was transformed from dense to disperse. At 2 h after activation, gamma-tubulin was localized between the segregated sister chromatids at telophase. However, at 3-6 h after activation, gamma-tubulin concentrated around the two female pronuclei during their formation and juxtaposition. Moreover, another group of MII oocytes were activated for 6 h and cultured in droplets of KSOM medium under mineral oil in 5% CO2 in air at 37 degrees C to permit parthenogenetic development. The embryos were collected and fixed at 3 h, 14 h, 16 h, and 18 h of culture. At 3 h after culture, i.e. at mitotic interphase, it was shown that amorphous gamma-tubulin distributed around the nuclei of early parthenogenetic embryos. At 24 h after culture, i.e. at prometaphase, gamma-tubulin migrated along the spindle microtubule to the two poles. Our results showed that gamma-tubulin had similar location patterns at metaphase, anaphase and telophase in meiosis and mitosis. It was concluded that gamma-tubulin assembly in parthenogenetically activated oocytes facilitated the formation of negative pole cap and the stabilization of microtubule, thus promoting the spindle formation at meiosis and mitosis. The relocation of gamma-tubulin at anaphase and telophase might be induced by the event of segregation of homologous chromosome being pulled away by the spindle. gamma-tubulin might contribute to the migration and juxtaposition of the two female pronuclei as well.
Animals ; Embryo, Mammalian ; Embryonic Development ; Female ; Meiosis ; Mice ; Mitosis ; Oocytes ; cytology ; Parthenogenesis ; Spindle Apparatus ; physiology ; Tubulin ; physiology

Parthenogenetic embryonic stem cells (pESCs) derived from bi-maternal genomes do not have competency of tetraploid complementation, due to lacking of paternal imprinting genes. To make pESCs possess fully development potentials and similar pluripotency to zygote-derived ESCs, we knocked out one allelic gene of the two essential maternal imprinting genes (H19 and IG) in their differentially methylated regions (DMR) via CRISPR/Cas9 system and obtained double knock out (DKO) pESCs. Maternal pESCs had similar morphology, expression levels of pluripotent makers and in vitro neural differentiation potentials to zygotes-derived ESCs. Besides that, DKO pESCs could contribute to full-term fetuses through tetraploid complementation, proving that they held fully development potentials. Derivation of DKO pESCs provided a type of major histocompatibility complex (MHC) matched pluripotent stem cells, which would benefit research in regenerative medicine.
Animals ; Embryonic Stem Cells ; Gene Knockout Techniques ; Genomic Imprinting ; Mice ; Parthenogenesis ; Pluripotent Stem Cells ; Regenerative Medicine ; Tetraploidy

Animals ; Embryonic Stem Cells ; diagnostic imaging ; metabolism ; Humans ; Mice, Inbred C57BL ; Parthenogenesis ; Telomere ; diagnostic imaging ; metabolism ; Transcriptome ; Ultrasonography

This study was performed to examine the effects of various macromolecules in in vitro growth (IVG) media on the growth, maturation, and parthenogenesis (PA) of pig oocytes derived from small antral follicles (SAF). Immature oocytes were cultured for two days in IVG medium supplemented with 10% (v/v) fetal bovine serum (FBS), 10% (v/v) pig follicular fluid (PFF), 0.4% (w/v) bovine serum albumin (BSA), or 0.1% (w/v) polyvinyl alcohol (PVA) and then maintained for 44 h for maturation. After IVG, the mean diameters of the SAF treated with FBS, PVA, and no IVG-MAF (113.0–114.8 µm) were significantly larger than that of no IVG-SAF (111.8 µm). The proportion of metaphase II oocytes was higher in PFF (73.6%) than in BSA (43.5%) and PVA (53.7%) but similar to that in the FBS treatment (61.5%). FBS and PFF increased cumulus expansion significantly compared to PVA and BSA while the intraoocyte glutathione content was not influenced by the macromolecules. Blastocyst formation of PA oocytes treated with FBS (51.8%), PFF (50.4%), and PVA (45.2%) was significantly higher than that of the BSA-treated oocytes (20.6%). These results show that the PFF and FBS treatments during IVG improved the growth, maturation, and embryonic development of SAF.
Blastocyst ; Embryonic Development ; Female ; Follicular Fluid ; Glutathione ; In Vitro Techniques ; Metaphase ; Oocytes ; Parthenogenesis ; Polyvinyl Alcohol ; Pregnancy ; Serum Albumin, Bovine

In this study we detected dynamic changes and function of beta-tubulin, a subtype of microtubule, during the first cleavage period in mouse parthenogenetic and in vitro fertilized embryos. Firstly, we compared the developmental potential of in vitro fertilized, parthenogenetic, and in vivo fertilized embryos in culture. Then, the dynamic changes of beta-tubulin and nucleus in parthenogenetic and in vitro fertilized preimplantation embryos were detected by immunofluorescence and confocal microscopy to analyze the role of microtubules in meiotic division and embryonic development. The results indicated that the development rate of in vivo fertilized embryos was significantly higher than that of in vitro fertilized or parthenogenetic embryos (P<0.05). However, there was no significant difference in developmental potential between in vitro fertilized and parthenogenetic embryos. During in vitro fertilization, oocyte was activated when sperm entered it. Oocyte resumed the second meiotic division. Condensed maternal chromosomes aligning at the equator of the spindle were pulled to the spindle poles by kinetochore microtubules in anaphase. Furthermore, in telophase, there were microtubules between the two sets of decondensed maternal chromosomes. One set formed the second polar body (Pb(2)), which was extruded to the perivitelline space. The other set formed female pronucleus. Meanwhile, 5-8 h after fertilization, sperm chromatin condensed and decondensed to form male pronucleus. Microtubule composed mesosome and cytaster remodeling around male and female pronuclei to form long microtubules, which pull the pronuclei to get close. During 4-6 h parthenogenetic activation, SrCl(2) activated oocytes to resume meiosis. As a consequence, sister chromatids were pulled to spindle poles. Cytochalasin B, which was applied in the medium, inhibited the extrusion of Pb(2). Two haploid pronuclei in the cytoplasm were connected by microtubules. Compared with that in in vitro fertilization, oocyte is easier to be activated in parthenogenetic activation. Chemical activation is more efficient than sperm penetration in in vitro fertilization as indicated by earlier and better remodeling of the microtubules.
Animals ; Blastocyst ; Cell Cycle ; Chromatin ; Embryonic Development ; Female ; Fertilization in Vitro ; Male ; Meiosis ; Mice ; Microtubules ; physiology ; Oocytes ; Parthenogenesis ; Pregnancy ; Sperm-Ovum Interactions