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Journal of Assisted Reproduction and... Jan 2008To determine the efficiency of sperm motion characteristics as predictors for normal (2PN) and polypronulceate (PPN) zygotes in IVF.
PURPOSE
To determine the efficiency of sperm motion characteristics as predictors for normal (2PN) and polypronulceate (PPN) zygotes in IVF.
METHODS
A retrospective cohort analysis for a total of 230 couples undergoing IVF treatment in a single infertility center.
RESULT(S)
Subsequent to semen analysis and hemizona assay, unexpected fertilization failure would appear to have occurred only extremely rarely (1/236, 0.4%). The rate of PPN, however, did arise and appeared to be related to certain sperm motion characteristics, such as lateral head displacement and concentration of progressive motile sperm. Interestingly, the patients featuring a high PPN rate (>20%) was associated with a greater pregnancy rate than those featuring a low PPN rate (<20%).
CONCLUSION
The sperm motion characteristics examined herein could be utilized to predict the rate of PPN in IVF. In order to enhance the rate of 2PN and maintain the relative high rate of clinical pregnancy, an efficient method needs further investigation and development.
Topics: Adult; Cohort Studies; Female; Fertilization in Vitro; Humans; Male; Oocytes; Ovulation Induction; Pregnancy; Retrospective Studies; Semen; Sperm Count; Sperm Motility; Sperm-Ovum Interactions; Zygote
PubMed: 18205036
DOI: 10.1007/s10815-007-9190-1 -
Mutation Research Oct 1995The ability of certain chemicals to increase the frequency of aneuploidy in mammalian oocytes elicits concern about human health and well-being. This concernment exists... (Review)
Review
The ability of certain chemicals to increase the frequency of aneuploidy in mammalian oocytes elicits concern about human health and well-being. This concernment exists because aneuploidy is the most prevalent class of human genetic disorders, and very little information exists about the etiology of aneuploidy. Although there are experimental models for studying aneuploidy in female germ cells and zygotes, these models are still being validated because insufficient information exists about the biological variables that can influence the degree of chemical-induced aneuploidy. In this regard, variables such as dose, solvent, use of gonadotrophins, mode and preovulatory time of chemical administration, time of cell harvest relative to the possibility of chemical-induced meiotic delay, criteria for cytogenetic analysis and data reporting, and an introduction to differences between cell types and sexes are presented. Besides these variables, additional information is needed about the various molecular mechanisms associated with oocyte meiotic maturation and the genesis of aneuploidy. Also, differences between the results from selected chromosome analysis and DNA-hybridization studies are presented. Based upon the various biologic endpoints measured and the differences in cellular physiology and biochemical pathways, agreement among the results from different aneuploidy assays cannot necessarily be expected. To gain further insight into the etiology of aneuploidy in female germ cells, information is needed about the chemical interactions between endogenous and exogenous compounds and those involved with oocyte meiotic maturation.
Topics: Aneuploidy; Animals; Cells, Cultured; Cytogenetics; Female; Gonadotropins; Humans; Meiosis; Menstrual Cycle; Oocytes; Solvents; Zygote
PubMed: 7491125
DOI: 10.1016/0165-1110(95)90009-8 -
Zygote (Cambridge, England) Feb 2000Early embryonic development is largely dependent on maternal RNAs and proteins synthesised during oogenesis. Zygotic transcription is an essential event that occurs at a... (Review)
Review
Early embryonic development is largely dependent on maternal RNAs and proteins synthesised during oogenesis. Zygotic transcription is an essential event that occurs at a species-specific time after fertilization. In the absence of zygotic transcription the embryo dies since it can no longer support requirements for successful embryo development. Molecular genetics of gene expression during early embryogenesis, especially in the bovine species, remain one of the unsolved questions in modern biology. Earlier studies suggested that embryonic transcription in cattle begins at the late 4-cell or 8-cell stage. However, more recent studies suggest that bovine zygotes and 2-cell embryos are both transcriptionally and translationally active. Moreover, changes in chromatin structure due to acetylation of core histones and DNA replication play important roles in the regulation of zygotic/embryonic gene expression. This review will summarise results of recent studies about the timing and mechanisms of zygotic/embryonic gene expression in cattle. In addition, terminology in the literature regarding gene expression during early embryogenesis will be clarified. These terminologies include: 'zygotic/embryonic gene expression', 'maternal to embryonic transition in control of development (MET)' and 'zygotic/embryonic genome activation (ZEGA)'.
Topics: Animals; Biological Clocks; Cattle; Cell Cycle; Chromatin; Embryo, Mammalian; Gene Expression Regulation, Developmental; RNA Polymerase I; RNA Polymerase II; Species Specificity; Transcription, Genetic; Zygote
PubMed: 10840878
DOI: 10.1017/s0967199400000861 -
Reproduction, Fertility, and Development 2006The effects of glutamine, hypotaurine, taurine and premixed solutions of essential amino acids (EAA) and non-essential amino acids (NEAA) on in vitro development of...
The effects of glutamine, hypotaurine, taurine and premixed solutions of essential amino acids (EAA) and non-essential amino acids (NEAA) on in vitro development of porcine zygotes were evaluated. The effects of refreshing the medium and replacing polyvinyl alcohol (PVA) with bovine serum albumin (BSA) on embryonic development were also investigated. Porcine zygotes produced by in vitro maturation (IVM) and in vitro fertilisation (IVF) were cultured in porcine zygote medium (PZM), as the basal culture medium, for 5 days after IVF. The total number of cells in blastocysts was significantly increased by the addition of 2 mm glutamine to PZM, as was blastocyst yields after supplementation with 0.25 to 4 mm glutamine. Addition of 1.25 to 10 mm hypotaurine to PZM significantly increased blastocyst yields. Addition of 5 mm taurine to PZM significantly increased blastocyst yield, whereas taurine had no effect on blastocyst yield in cultures already containing 5 mm hypotaurine. Adding 1 x EAA significantly increased the rate of blastocyst formation compared with no or 2 x EAA, whereas 2 x NEAA significantly increased the total cell numbers in blastocysts compared with no NEAA. Refreshing the medium at Day 3 had no effect on blastocyst yields, whereas medium change significantly reduced the total cell numbers in blastocysts. Adjusting the amino acid concentrations of a chemically defined medium can improve the developmental competence of porcine embryo.
Topics: Amino Acids; Animals; Cattle; In Vitro Techniques; Polyvinyl Alcohol; Serum Albumin, Bovine; Swine; Taurine; Zygote
PubMed: 17032588
DOI: 10.1071/rd06032 -
Human Reproduction (Oxford, England) Mar 2008BACKGROUND Sperm aster organization during bovine and human fertilization requires a paternally-derived centriole that must first disengage from the sperm tail...
BACKGROUND Sperm aster organization during bovine and human fertilization requires a paternally-derived centriole that must first disengage from the sperm tail connecting-piece. We investigated the participation of the 26S proteasome in this process. METHODS Proteasome localization and enzymatic activity were studied in normal and pathological human spermatozoa by immunocytochemistry and enzyme-substrate assays. The role of proteasomes during bovine zygote development was investigated using a pharmacological proteasome-inhibitor, MG132, and with anti-proteasome antibodies delivered by Streptolysin O-permeabilization or with the Chariot reagent. Human zygotes discarded after ICSI failures (n = 28) were also examined. RESULTS Proteasomes were localized in the sperm acrosome and connecting-piece, as well as in the pronuclei of bovine and human zygotes. Proteasomal enzymatic activities were decreased in defective human spermatozoa. Disrupted sperm aster formation and pronuclear development were found after pharmacological and immunological block of proteasomes in human/bovine spermatozoa and oocytes, as well as in 28 discarded human post-ICSI fertilization failures. CONCLUSIONS Specific proteasome inhibition disrupts sperm aster formation and pronuclear development/apposition in bovine and human zygotes. Human spermatozoa with defective centriolar/pericentriolar structures have decreased proteasomal enzymatic activity. Release of a functional sperm centriole that acts as a zygote microtubule-organizing center probably relies on selective proteasomal proteolysis. These findings suggest an important role of sperm proteasomes in zygotic development.
Topics: Acrosome; Animals; Cattle; Female; Fertilization; Fertilization in Vitro; Humans; Immunohistochemistry; Leupeptins; Male; Proteasome Endopeptidase Complex; Sperm Injections, Intracytoplasmic; Sperm Tail; Spermatozoa; Zygote
PubMed: 18089554
DOI: 10.1093/humrep/dem385 -
Proceedings of the National Academy of... Feb 2019In most flowering plants, the asymmetric cell division of the zygote is the initial step in establishing the apical-basal axis of the mature plant. The zygote is...
In most flowering plants, the asymmetric cell division of the zygote is the initial step in establishing the apical-basal axis of the mature plant. The zygote is polarized, possessing the nucleus at the apical tip and large vacuoles at the basal end. Despite their known polar localization, whether the positioning of the vacuoles and the nucleus is coordinated and what the role of the vacuole is in the asymmetric zygotic division remain elusive. In the present study, we utilized a live-cell imaging system to visualize the dynamics of vacuoles during the entire process of zygote polarization in Image analysis revealed that the vacuoles formed tubular strands around the apically migrating nucleus. They gradually accumulated at the basal region and filled the space, resulting in asymmetric distribution in the mature zygote. To assess the role of vacuoles in the zygote, we screened various vacuole mutants and identified that (), in which the vacuolar structural change was impaired, failed to form tubular vacuoles and to polarly distribute the vacuole. In , large vacuoles occupied the apical tip and thus nuclear migration was blocked, resulting in a more symmetric zygotic division. We further observed that tubular vacuole formation and asymmetric vacuolar distribution both depended on the longitudinal array of actin filaments. Overall, our results show that vacuolar dynamics is crucial not only for the polar distribution along actin filaments but also for adequate nuclear positioning, and consequently zygote-division asymmetry.
Topics: Actin Cytoskeleton; Arabidopsis; Arabidopsis Proteins; Asymmetric Cell Division; Cell Nucleus; Cell Polarity; Chloroplast Proteins; Fluorescent Antibody Technique; Mutation; Vacuoles; Zygote
PubMed: 30651313
DOI: 10.1073/pnas.1814160116 -
Cell Calcium Jul 2000Fertilization-induced Ca(2+)spiking in mouse zygotes ceases at the end of pre-G1 as pronuclei (PN) form. In the present studies we found that there was no consistent...
Fertilization-induced Ca(2+)spiking in mouse zygotes ceases at the end of pre-G1 as pronuclei (PN) form. In the present studies we found that there was no consistent temporal relationship between PN formation and cessation of spiking. We also show that nucleate and anucleate fragments of zygotes, obtained by bisection of fertilized eggs prior to PN formation, both ceased spiking at times that did not depend on the presence of the PN. We, therefore, concluded that formation of the PN does not cause spiking cessation. The possibility that cessation of the fertilization-induced Ca(2+)spiking may be mediated by a redox sensitive mechanism affecting the sensitivity of Ca(2+)release from internal stores is proposed. At first mitosis, a small proportion of zygotes show low amplitude calcium spikes prior to pronuclear envelope breakdown (PNEBD), whereas all zygotes spiked at this time in the presence of high extracellular Ca(2+)and dithiothreitol. Nucleated zygotic fragments also spiked before PNEBD whereas anucleated ones rarely did. Exit from G2 was required for this spiking to be observed in nucleated zygotes or fragments. Arrest in M-phase resulted in the appearance of a prolonged series of small amplitude spikes. It is concluded that the spiking at mitosis is cell cycle regulated and may differ qualitatively in its control from that at fertilization.
Topics: Animals; Calcium Signaling; Cell Cycle; Cell Nucleus; Dithiothreitol; Fertilization; Mice; Oxidation-Reduction; Zygote
PubMed: 10942703
DOI: 10.1054/ceca.2000.0128 -
Seikagaku. the Journal of Japanese... Apr 2013
Review
Topics: Animals; Cell Nucleus; Chromatin; DNA Methylation; Fertilization in Vitro; Histones; Mice; Zygote
PubMed: 23717876
DOI: No ID Found -
Journal of General Microbiology Dec 1987The topology of tubulin and actin during mating of Saccharomyces cerevisiae was analysed by fluorescence microscopy with the monoclonal anti-tubulin antibody Tu01 and...
The topology of tubulin and actin during mating of Saccharomyces cerevisiae was analysed by fluorescence microscopy with the monoclonal anti-tubulin antibody Tu01 and rhodamine-labelled phalloidin. Preconjugatory cells displayed an asymmetric distribution of the microtubule and actin cytoskeleton and an overall polarization of the cells preceding cell fusion. Prior to karyogamy, the haploid spindle pole bodies were associated with abundant cytoplasmic microtubules. Budding zygotes revealed the same tubulin and actin patterns as vegetative cells. Treatment of the mating mixture with the microtubule inhibitor nocodazole (10 micrograms ml-1) did not prevent polarization and fusion of haploids, zygote formation and emergence of the first zygotic bud. In marked contrast, the migration of the nucleus in preconjugatory cells as well as nuclear migration and fusion within the zygotes was unequivocally blocked by the action of the drug. It is suggested that the problem of the morphogenesis of mating should be approached by considering interactions at the cell periphery.
Topics: Actins; Benzimidazoles; Cell Cycle; Conjugation, Genetic; Microscopy, Fluorescence; Nocodazole; Saccharomyces cerevisiae; Tubulin; Zygote
PubMed: 3332685
DOI: 10.1099/00221287-133-12-3355 -
Cold Spring Harbor Protocols Jul 2018This protocol describes the injection of RNA into zygotes.
This protocol describes the injection of RNA into zygotes.
Topics: Animals; Mice; Microinjections; RNA; Transcription, Genetic; Zygote
PubMed: 29967270
DOI: 10.1101/pdb.prot093906