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Reproductive Medicine and Biology Mar 2011The size of the perivitelline space and the incidence of polyspermy were observed in ovulated and cultured oocytes from rabbits and hamsters with or without treatment by...
PURPOSE
The size of the perivitelline space and the incidence of polyspermy were observed in ovulated and cultured oocytes from rabbits and hamsters with or without treatment by 4-methylumbelliferone (MU), an inhibitor of hyaluronic acid (HA) synthase, in order to examine the relationship between the incidence of polyspermy and the size of the perivitelline space. The amount of HA in the medium with MU-treated hamster oocytes was measured and compared with that in the medium with untreated oocytes.
METHODS
The perivitelline space of oocytes with 1st polar bodies was measured by use of a micrometer under a microscope, and the incidence of polyspermy was observed in the oocytes after insemination. The amount of HA in the medium was examined using an enzyme-linked immunosorbent assay. The distribution of cortical granules was observed by staining with FITC-conjugated LCA.
RESULTS
In both rabbit and hamster, the mean size of the perivitelline space was significantly smaller and the incidence of polyspermy was significantly higher in the cultured and MU-treated oocytes than in the ovulated and untreated oocytes. The mean amount of HA in the medium with MU-treated oocytes (8.96 pg) was significantly smaller than that in the medium with untreated oocytes (21.77 pg). The distribution of cortical granules did not differ among the ovulated, cultured, and MU-treated oocytes.
CONCLUSIONS
These findings suggest that the size of the perivitelline space is closely related to the incidence of polyspermy, and that the oocyte itself synthesizes and secretes the HA involved in the enlargement of the perivitelline space.
PubMed: 29662352
DOI: 10.1007/s12522-010-0067-0 -
International Journal of Molecular... Jan 2022Embryo fragmentation represents a phenomenon generally characterized by the presence of membrane-bound extracellular cytoplasm into the perivitelline space. Recent... (Review)
Review
Embryo fragmentation represents a phenomenon generally characterized by the presence of membrane-bound extracellular cytoplasm into the perivitelline space. Recent evidence supports the cellular and molecular heterogeneity of embryo fragments. In this narrative review, we described the different embryo fragment-like cellular structures in their morphology, molecular content, and supposed function and have reported the proposed theories on their origin over the years. We identified articles related to characterization of embryo fragmentation with a specific literature search string. The occurrence of embryo fragmentation has been related to various mechanisms, of which the most studied are apoptotic cell death, membrane compartmentalization of altered DNA, cytoskeletal disorders, and vesicle formation. These phenomena are thought to result in the extrusion of entire blastomeres, release of apoptotic bodies and other vesicles, and micronuclei formation. Different patterns of fragmentation may have different etiologies and effects on embryo competence. Removal of fragments from the embryo before embryo transfer with the aim to improve implantation potential should be reconsidered on the basis of the present observations.
Topics: Apoptosis; Blastomeres; Cell Division; Cell-Derived Microparticles; Embryo Implantation; Embryo Transfer; Embryo, Mammalian; Embryonic Development; Humans; Micronucleus, Germline
PubMed: 35163271
DOI: 10.3390/ijms23031349 -
Frontiers in Cell and Developmental... 2020The presence of cellular fragments in the perivitelline space is a commonly used parameter to determine quality before transfer of produced (IVP) embryos. However, this...
The presence of cellular fragments in the perivitelline space is a commonly used parameter to determine quality before transfer of produced (IVP) embryos. However, this parameter is difficult to assess after blastocyst expansion. In this study, we used mechanical hatching to confirm the presence of cellular fragments in the perivitelline space of bovine IVP blastocysts. We further looked for associations between possible apoptosis within extruded cells/ cellular fragments and the quality of bovine blastocysts using quantitative RT-PCR and immunofluorescence. Surprisingly, more than 42% of expanded blastocysts had cellular fragments in the perivitelline space; however, more than 37% of extruded cells were TUNEL negative. We observed no significant difference in embryo quality between expanded blastocysts with and without cellular fragments in the perivitelline space. Overall, our data suggest that embryos extrude abnormal cells to maintain their developmental potential. The presence of fragmented cells is not an indicator of embryo quality.
PubMed: 33469540
DOI: 10.3389/fcell.2020.616801 -
JBRA Assisted Reproduction Aug 2023To evaluate the origin and ultrastructure of the coarse granules in the perivitelline space (PVS) of oocytes of a group of couples attending assisted reproduction...
OBJECTIVE
To evaluate the origin and ultrastructure of the coarse granules in the perivitelline space (PVS) of oocytes of a group of couples attending assisted reproduction treatment.
METHODS
The ultrastructure of five oocytes with coarse granulues in the PVS obtained from three patients were evaluated by transmission electron microscopy (TEM). The influence of the ovulation induction regimen on the formation of granules in the PVS of the oocytes of 214 couples and the developmental capacity of these oocytes presenting granules in the PVS was analyzed retrospectively.
RESULTS
In TEM analysis, the microvilli structure was irregular, short, and loosely scattered through the oolemma in the oocytes presenting coarse granules in the PVS. Furthermore, dense lipid droplets were identified within the PVS and the surrounding cumulus cells. In retrospective analysis, the number of oocytes with coarse granules in the PVS was positively correlated with the duration of antagonist administration (r=0.23, p=0.013). Regardless of the type of granule, the presence of coarse or moderately coarse granules in the PVS was positively correlated with low-quality embryos on D3 (r=0.29, p=0.005) and the total number of arrested embryos up to D3 (r=0.33, p<0.001). Furthermore, the presence of coarse granules in the PVS severely exacerbated miscarriage rates.
CONCLUSIONS
Our findings suggest that the presence of especially coarse granules in the PVS is correlated with the reduction of further embryonic developmental capacity in post-implantation stages of embryonic development, indicating a negative impact from aggressive ovulation induction protocols on developing oocytes.
PubMed: 37579275
DOI: 10.5935/1518-0557.20230032 -
Medicina (Kaunas, Lithuania) 2009In vitro fertilization technology consists of the selection and fertilization of oocytes, the production and transplantation of embryos to recipients. The quality of... (Comparative Study)
Comparative Study Review
In vitro fertilization technology consists of the selection and fertilization of oocytes, the production and transplantation of embryos to recipients. The quality of oocytes has a direct impact on the fertilization and developmental competence of oocytes. Criteria that show the quality of oocytes are subdivided into morphological, cellular, and molecular. The aim of this article was to review the morphological criteria that are used for estimation of the quality of oocytes before their fertilization in vitro. These criteria include the evaluation of the structure of oocyte: cumulus complex, oocyte cytoplasm, polar body, perivitelline space, zona pellucida, and meiotic spindle.
Topics: Adult; Age Factors; Aneuploidy; Birefringence; Cytoplasm; Embryonic Development; Female; Fertilization in Vitro; Humans; Meiosis; Oocytes; Sperm Injections, Intracytoplasmic; Staining and Labeling; Vitelline Membrane; Zona Pellucida
PubMed: 19667744
DOI: No ID Found -
Proceedings of the National Academy of... May 2023In recent years, cellular biomechanical properties have been investigated as an alternative to morphological assessments for oocyte selection in reproductive science....
In recent years, cellular biomechanical properties have been investigated as an alternative to morphological assessments for oocyte selection in reproductive science. Despite the high relevance of cell viscoelasticity characterization, the reconstruction of spatially distributed viscoelastic parameter images in such materials remains a major challenge. Here, a framework for mapping viscoelasticity at the subcellular scale is proposed and applied to live mouse oocytes. The strategy relies on the principles of optical microelastography for imaging in combination with the overlapping subzone nonlinear inversion technique for complex-valued shear modulus reconstruction. The three-dimensional nature of the viscoelasticity equations was accommodated by applying an oocyte geometry-based 3D mechanical motion model to the measured wave field. Five domains-nucleolus, nucleus, cytoplasm, perivitelline space, and zona pellucida-could be visually differentiated in both oocyte storage and loss modulus maps, and statistically significant differences were observed between most of these domains in either property reconstruction. The method proposed herein presents excellent potential for biomechanical-based monitoring of oocyte health and complex transformations across lifespan. It also shows appreciable latitude for generalization to cells of arbitrary shape using conventional microscopy equipment.
Topics: Animals; Mice; Oocytes; Zona Pellucida; Cytoplasm; Microscopy
PubMed: 37186851
DOI: 10.1073/pnas.2213836120 -
Biology of Reproduction May 2014In recent years, the study of mammalian acrosomal exocytosis has produced some major advances that challenge the long-held, general paradigms in the field. Principally,... (Review)
Review
In recent years, the study of mammalian acrosomal exocytosis has produced some major advances that challenge the long-held, general paradigms in the field. Principally, the idea that sperm must be acrosome-intact to bind to the zona pellucida of unfertilized eggs, based largely on in vitro fertilization studies of mouse oocytes denuded of the cumulus oophorus, has been overturned by experiments using state-of-the-art imaging of cumulus-intact oocytes and fertilization experiments where eggs were reinseminated by acrosome-reacted sperm recovered from the perivitelline space of zygotes. In light of these results, this minireview highlights a number of unresolved questions and emphasizes the fact that there is still much work to be done in this exciting field. Future experiments using recently advanced technologies should lead to a more complete and accurate understanding of the molecular mechanisms governing the fertilization process in mammals.
Topics: Acrosome Reaction; Animals; Exocytosis; Female; Male; Mice; Sperm-Ovum Interactions; Spermatozoa
PubMed: 24671881
DOI: 10.1095/biolreprod.114.117911 -
Journal of Assisted Reproduction and... Dec 2002To study the effect of the presence of coarse granules in the perivitelline space (PVS) of oocytes on embryonic development, and on implantation and pregnancy rates in...
PURPOSE
To study the effect of the presence of coarse granules in the perivitelline space (PVS) of oocytes on embryonic development, and on implantation and pregnancy rates in IVF.
METHODS
The study population included 24 patients treated during the period 1995-2000. The majority or all of their oocytes exhibited repeatedly coarse granulation in the PVS. Clinical and laboratory cycle characteristics of their 65 IVF-ICSI cycles and the resulting implantation and pregnancy rates were compared to a matched control group of 65 IVF- ICSI cycles without granulation in the PVS.
RESULTS
A total of 623 oocytes were retrieved, 418 oocytes fertilized, and 246 embryos were transferred in the study group. No difference was detected between the study and control group with regard to patients' clinical data, IVF cycle characteristics, mean number of oocytes retrieved and fertilized, and mean number of embryos transferred. Only seven pregnancies were achieved in the study group, leading to pregnancy and implantation rates of 10.7 and 5.7%, respectively. Pregnancy and implantation rates were significantly higher in the control group of matched IVF-ICSI cycles without granulation in the PVS (32.5 and 11.5%, respectively).
CONCLUSIONS
The presence of coarse granules in the PVS correlates with low implantation and pregnancy rates in IVF-ICSI cycles and might be regarded as a distinct entity, part of the yet poorly defined condition of "egg factor infertility."
Topics: Adult; Blastocyst; Case-Control Studies; Embryo Implantation; Embryo Transfer; Female; Fertilization in Vitro; Humans; Predictive Value of Tests; Pregnancy; Pregnancy Rate; Sperm Injections, Intracytoplasmic; Treatment Outcome; Vitelline Membrane
PubMed: 12503885
DOI: 10.1023/a:1021243530358 -
Journal of the Turkish German... 2014In assisted reproductive technology (ART), high embryo quality is closely related to high-quality oocytes. Cytoplasmic maturation and extracytoplasmic maturation are the...
OBJECTIVE
In assisted reproductive technology (ART), high embryo quality is closely related to high-quality oocytes. Cytoplasmic maturation and extracytoplasmic maturation are the most important components in determining oocyte quality. One of the most important components of extracytoplasmic maturation is perivitelline abnormalities. The aim of this study is to determine the effect of perivitelline abnormalities on the development of high-quality embryos.
MATERIAL AND METHODS
The study material consisted of 217 of 1154 oocytes from 98 intracytoplasmic sperm injection (ICSI) cycles undertaken due to male factor infertility. Only cycles with long gonadotropin-releasing hormone analogs combined with recombinant Follicle-stimulating hormone (rec-FSH) were included in study. We compared 105 metaphase-II oocytes that had dominantly perivitelline space abnormalities (large perivitelline space with or without granules) with 112 normal metaphase-II oocytes, based on the embryo grade determined by Alpha Scientists in Reproductive Medicine and the European Society of Human Reproduction and Embryology (ESHRE) Special Interest Group of Embryology. Normal metaphase-II oocytes were characterized by a round, clear zona pellucida; a small perivitelline space containing a single unfragmented first polar body; and a pale, moderately granular cytoplasm with no inclusions.
RESULTS
The development rates of Grade I, II, and III embryos were 68.5%, 23.8%, and 7.7%, respectively, in the 105 oocytes with perivitelline abnormalities. The development rates of Grade I, II, and III embryos were 82.1%, 17.9%, and 0%, respectively, in the 112 morphologically normal oocytes. When compared with normal oocytes, Grade I (68.5% vs. 82.1%, p value; 0.019) and Grade III (7.7% vs. 0%, p value; 0.003) embryo development rates were significantly lower in oocytes that had perivitelline abnormalities.
CONCLUSION
It is important to analyze oocyte quality using multiple parameters, including the perivitelline space. Perivitelline space abnormalities might negatively affect embryo development in male factor-infertile couples that are stimulated with rec-FSH. Therefore, when choosing embryos for transfer, we must take into consideration the historical oocyte data.
PubMed: 25317044
DOI: 10.5152/jtgga.2014.13091 -
PloS One 2023Generating non-human primate models of human diseases is important for the development of therapeutic strategies especially for neurodegenerative diseases. The common...
Generating non-human primate models of human diseases is important for the development of therapeutic strategies especially for neurodegenerative diseases. The common marmoset has attracted attention as a new experimental animal model, and many transgenic marmosets have been produced using lentiviral vector-mediated transgenesis. However, lentiviral vectors have a size limitation of up to 8 kb in length for transgene applications. Therefore, the present study aimed to optimize a piggyBac transposon-mediated gene transfer method in which transgenes longer than 8 kb were injected into the perivitelline space of marmoset embryos, followed by electroporation. We constructed a long piggyBac vector carrying the gene responsible for Alzheimer's disease. The optimal weight ratio of the piggyBac transgene vector to the piggyBac transposase mRNA was examined using mouse embryos. Transgene integration into the genome was confirmed in 70.7% of embryonic stem cells established from embryos injected with 1000 ng of transgene and transposase mRNA. Under these conditions, long transgenes were introduced into marmoset embryos. All embryos survived after transgene introduction treatment, and transgenes were detected in 70% of marmoset embryos. The transposon-mediated gene transfer method developed in this study can be applied to the genetic modification of non-human primates, as well as large animals.
Topics: Animals; Mice; Callithrix; Genetic Vectors; Gene Transfer Techniques; Transgenes; Callitrichinae; Transposases; RNA, Messenger; DNA Transposable Elements
PubMed: 37294815
DOI: 10.1371/journal.pone.0287065