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Reproductive Biomedicine Online Mar 2017
Topics: Embryo Culture Techniques; Humans; Oocytes
PubMed: 28034688
DOI: 10.1016/j.rbmo.2016.12.006 -
Reproductive Biomedicine Online Mar 2017
Topics: Embryo Culture Techniques; Humans; Oocytes
PubMed: 28024934
DOI: 10.1016/j.rbmo.2016.12.008 -
Methods in Molecular Biology (Clifton,... 2023Interspecies somatic cell nuclear transfer (iSCNT) contributes to the preservation of endangered species, albeit nuclear-mitochondrial incompatibilities constrain its...
Interspecies somatic cell nuclear transfer (iSCNT) contributes to the preservation of endangered species, albeit nuclear-mitochondrial incompatibilities constrain its application. iSCNT, coupled with ooplasm transfer (iSCNT-OT), has the potential to overcome the challenges associated with species- and genus-specific differences in nuclear-mitochondrial communication. Our iSCNT-OT protocol combines the transfer of both bison (Bison bison bison) somatic cell and oocyte ooplasm by a two-step electrofusion into bovine (Bos taurus) enucleated oocytes. The procedures described herein could be used in further studies to determine the effects of crosstalk between nuclear and ooplasmic components in embryos carrying genomes from different species.
Topics: Animals; Cattle; Bison; Nuclear Transfer Techniques; Cytoplasm; Mitochondria; Cell Nucleus
PubMed: 37041340
DOI: 10.1007/978-1-0716-3064-8_14 -
Human Reproduction (Oxford, England) Nov 2009The ooplasm plays a central role in forming the paternal pronucleus, and subsequently in regulating the expression of paternally inherited chromosomes. Previous studies...
BACKGROUND
The ooplasm plays a central role in forming the paternal pronucleus, and subsequently in regulating the expression of paternally inherited chromosomes. Previous studies in mice have revealed genetic differences in paternal genome processing by ooplasm of different genotypes. Ooplasm donation coupled to intracytoplasmic sperm injection (ICSI) has been used in human assisted reproductive technology (ART). This procedure exposes the developing paternal pronucleus to 'foreign' ooplasm, which may direct aberrant epigenetic processing. The potential effects of the foreign ooplasm on epigenetic information in the paternal pronucleus are unknown; however, some human progeny from ooplasm donation procedures display abnormalities.
METHODS
In this study, we employed inter-genotype ooplasm transfer followed by ICSI using two mouse strains, C57BL/6 and DBA/2, to explore the influence of foreign ooplasm on paternal pronucleus function. In order to assay for effects on the paternal genome without masking effects of the maternal genome, we examined ooplasm effects in diploid androgenones, which are produced by pronuclear transfer to contain exclusively two paternal sets of chromosomes, in combination with ICSI.
RESULTS
There was no significant effect of intra-strain ooplasm transfer among androgenones made with either C57BL/6 or DBA/2 oocytes. There was a significant negative effect on androgenone blastocyst development with inter-genotype transfer (10% volume) of DBA/2 ooplasm to C57BL/6 oocytes (P < 0.05). The reciprocal inter-genotype ooplasm transfer had no significant effect.
CONCLUSIONS
Thus, inter-genotype ooplasm transfer in conjunction with ICSI can alter the function of the paternal genome. However, the effect of foreign ooplasm is restricted to a negative effect, with no evidence of a positive effect. This study provides important new information about the possible consequences of ooplasm donation in human ART.
Topics: Animals; Cell Nucleus; Cytoplasm; Embryo Culture Techniques; Embryonic Development; Epigenesis, Genetic; Female; Genome; Genotype; Inheritance Patterns; Male; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Oocytes; Sperm Injections, Intracytoplasmic; Spermatozoa
PubMed: 19661122
DOI: 10.1093/humrep/dep286 -
BioRxiv : the Preprint Server For... Apr 2023Life in complex systems, such as cities and organisms, comes to a standstill when global coordination of mass, energy, and information flows is disrupted. Global...
Life in complex systems, such as cities and organisms, comes to a standstill when global coordination of mass, energy, and information flows is disrupted. Global coordination is no less important in single cells, especially in large oocytes and newly formed embryos, which commonly use fast fluid flows for dynamic reorganization of their cytoplasm. Here, we combine theory, computing, and imaging to investigate such flows in the Drosophila oocyte, where streaming has been proposed to spontaneously arise from hydrodynamic interactions among cortically anchored microtubules loaded with cargo-carrying molecular motors. We use a fast, accurate, and scalable numerical approach to investigate fluid-structure interactions of 1000s of flexible fibers and demonstrate the robust emergence and evolution of cell-spanning vortices, or twisters. Dominated by a rigid body rotation and secondary toroidal components, these flows are likely involved in rapid mixing and transport of ooplasmic components.
PubMed: 37066165
DOI: 10.1101/2023.04.04.534476 -
Current Biology : CB Aug 2019Actin networks in the bulk cytoplasm, rather than cortical dynamics, drive ooplasm segregation in zebrafish oocytes. A contracting actin network drags the ooplasm toward...
Actin networks in the bulk cytoplasm, rather than cortical dynamics, drive ooplasm segregation in zebrafish oocytes. A contracting actin network drags the ooplasm toward the animal pole, while 'comet tails' push the yolk granules in the opposite direction.
Topics: Actins; Animals; Cytoplasm; Oocytes; Zebrafish
PubMed: 31386856
DOI: 10.1016/j.cub.2019.06.063 -
Zygote (Cambridge, England) May 2011Although interspecies somatic cell nuclear transfer (iSCNT) has potential applications in the conservation of exotic species, an in vitro developmental block has been...
Although interspecies somatic cell nuclear transfer (iSCNT) has potential applications in the conservation of exotic species, an in vitro developmental block has been observed in embryos produced by this approach. It has been suggested that mitochondrial mismatch between donor cell and recipient oocyte could cause embryonic developmental arrest. A series of experiments was conducted to investigate the effect of mixed mitochondrial populations (heteroplasmy) on early development of iSCNT-derived cloned embryos. The effect of combining the techniques of ooplasm transfer (OT) and somatic cell nuclear transfer (SCNT) was examined by monitoring in vitro embryonic development; the presence and pattern of migration of foreign mitochondria after OT was analysed by MitoTracker staining. In addition, the effect of transferring caprine ooplasm (iOT) into the bovine enucleated oocytes used in iSCNT was analysed. There was no significant effect of the sequence of events (OT-SCNT or SCNT-OT) on the number of fused, cleaved, blastocyst or hatched blastocyst stage embryos. MitoTracker Green staining of donor oocytes used for OT confirmed the introduction of foreign mitochondria. The distribution pattern of transferred mitochondria most commonly remained in a distinct cluster after 12, 74 and 144 h of in vitro culture. When goat ooplasm was injected into bovine enucleated oocytes (iSCNT), there was a reduction (p < 0.05) in fusion (52 vs. 82%) and subsequent cleavage rates (55 vs. 78%). The procedure of iOT prior to iSCNT had no effect in overcoming the 8- to 16-cell in vitro developmental block, and only parthenogenetic cow and goat controls reached the blastocyst (36 and 32%) and hatched blastocyst (25 and 12%) stages, respectively. This study indicates that when foreign mitochondria are introduced at the time of OT, these organelles tend to remain as distinct clusters without relocation after a few mitotic divisions. Although the bovine cytoplast appears capable of supporting mitotic divisions after iOT-iSCNT, heteroplasmy or mitochondrial incompatibilities may affect nuclear-ooplasmic events occurring at the time of genomic activation.
Topics: Animals; Blastocyst; Cattle; Cell Nucleus; Cloning, Organism; Cytoplasm; Embryo, Mammalian; Embryonic Development; Female; Genome; Goats; Mitochondria; Nuclear Transfer Techniques; Oocytes
PubMed: 20735895
DOI: 10.1017/S0967199410000419 -
Reproduction in Domestic Animals =... Jun 2017Somatic cell nuclear transfer (SCNT) is considered as the technique in which a somatic cell is introduced into an enucleated oocyte to make a cloned animal. However, it...
Somatic cell nuclear transfer (SCNT) is considered as the technique in which a somatic cell is introduced into an enucleated oocyte to make a cloned animal. However, it is unavoidable to lose a small amount of the ooplasm during enucleation step during SCNT procedure. The present study was aimed to uncover whether the supplement of autologous ooplasm could ameliorate the oocyte competence so as to improve low efficiency of embryo development in porcine SCNT. Autologous ooplasm-transferred (AOT) embryos were generated by the supplementation with autologous ooplasm into SCNT embryos. They were comparatively evaluated with respect to embryo developmental potential, the number of apoptotic body formation and gene expression including embryonic lineage differentiation, apoptosis, epigenetics and mitochondrial activity in comparison with parthenogenetic, in vitro-fertilized (IVF) and SCNT embryos. Although AOT embryos showed perfect fusion of autologous donor ooplasm with recipient SCNT embryos, the supplement of autologous ooplasm could not ameliorate embryo developmental potential in regard to the rate of blastocyst formation, total cell number and the number of apoptotic body. Furthermore, overall gene expression of AOT embryos was presented with no significant alterations in comparison with that of SCNT embryos. Taken together, the results of AOT demonstrated inability to make relevant values improved from the level of SCNT embryos to their IVF counterparts.
Topics: Animals; Apoptosis; Blastocyst; Embryo, Mammalian; Embryonic Development; Epigenesis, Genetic; Female; Fertilization in Vitro; Gene Expression Regulation, Developmental; Nuclear Transfer Techniques; Oocytes; Parthenogenesis; Sus scrofa
PubMed: 28191700
DOI: 10.1111/rda.12929 -
Human Reproduction (Oxford, England) Oct 2002ICSI bypasses the sperm-oolemma interactions that, in normal fertilization, depend on completion of the acrosome reaction. Morphological changes in the acrosomes of...
BACKGROUND
ICSI bypasses the sperm-oolemma interactions that, in normal fertilization, depend on completion of the acrosome reaction. Morphological changes in the acrosomes of sperm in the ooplasm were therefore examined following IVF and ICSI using pig gametes.
METHODS
In-vitro-matured porcine oocytes were used for ICSI or IVF. Oocytes were then stained with fluorescein isothiocyanate-conjugated peanut agglutinin lectin (FITC-PNA), which specifically labels the outer acrosomal membrane of boar sperm and the cortical granules (CG) in porcine oocytes. This was followed by observation under a confocal laser scanning microscope.
RESULTS
In ICSI, PNA showed the presence of disintegrated acrosomes that classified into four categories. Heterogeneous chromatin decondensation was observed in the sperm with intact/disintegrated acrosome, whereas acrosomes were barely detected in oocytes which had formed a male pronucleus. Both in ICSI and IVF, PNA-positive tails were concomitantly observed with one type of disintegrated acrosome, which was considered to be acrosome-reacted. The disappearance of CG in activated oocytes after ICSI was similar to that after IVF.
CONCLUSIONS
The PNA-binding properties of sperm head components introduced into the ooplasm during ICSI are different from those after IVF. The delay of sperm chromatin decondensation is associated with that of acrosomal disassembly. Acrosomes appear to disintegrate in the ooplasm whether or not the acrosome reaction has taken place. Oocytes undergoing ICSI appear normally activated in terms of meiotic resumption and CG exocytosis.
Topics: Acrosome; Animals; Cytoplasm; Female; Fertilization in Vitro; Fluorescein-5-isothiocyanate; Fluorescent Dyes; Male; Meiosis; Oocytes; Peanut Agglutinin; Sperm Injections, Intracytoplasmic; Spermatozoa; Swine
PubMed: 12351545
DOI: 10.1093/humrep/17.10.2657 -
Biochemical and Biophysical Research... Aug 2014A description and update of the "egg-as-novelty" hypothesis is presented. It is proposed that the major animal phylum-characteristic suites of morphological motifs first... (Review)
Review
A description and update of the "egg-as-novelty" hypothesis is presented. It is proposed that the major animal phylum-characteristic suites of morphological motifs first emerged more than a half-billion years ago in multicellular aggregates and clusters that did not exhibit an egg-soma divergence. These pre-metazoan bodies were organized by "dynamical patterning modules" (DPMs), physical processes and effects mobilized on the new multicellular scale by ancient conserved genes that came to mediate cell-cell interactions in these clusters. "Proto-eggs" were enlarged cells that through cleavage, or physical confinement by a secreted matrix, served to enforce genomic and genetic homogeneity in the cell clusters arising from them. Enlargement of the founder cell was the occasion for spontaneous intra-egg spatiotemporal organization based on single-cell physiological functions - calcium transients and oscillations, cytoplasmic flows - operating on the larger scale. Ooplasmic segregation by egg-patterning processes, while therefore not due to adaptive responses to external challenges, served as evolutionarily fertile "pre-adaptations" by making the implementation of the later-acting (at the multicellular "morphogenetic stage" of embryogenesis) DPMs more reliable, robust, and defining of sub-phylum morphotypes. This perspective is seen to account for a number of otherwise difficult to understand features of the evolution of development, such as the rapid diversification of biological forms with a conserved genetic toolkit at the dawn of animal evolution, the capability of even obligatory sexual reproducers to propagate vegetatively, and the "embryonic hourglass" of comparative developmental biology.
Topics: Animals; Biological Evolution; Body Patterning; Chimera; Embryonic Development; Female; Fertilization; Growth and Development; Male; Models, Biological; Ovum; Species Specificity
PubMed: 24704442
DOI: 10.1016/j.bbrc.2014.03.132