Human zygote morphological indicators of higher rate of arrest at the first cleavage stage

Zygote ◽  
2010 ◽  
Vol 19 (4) ◽  
pp. 339-344 ◽  
Author(s):  
Raquel Blanes Zamora ◽  
Rebeca Vaca Sánchez ◽  
Jonay González Pérez ◽  
Rubí Rodríguez Díaz ◽  
Delia Báez Quintana ◽  
...  
Keyword(s):  
Prospective Observational Study ◽  
Polar Body ◽  
Morphological Features ◽  
Chromosomal Anomalies ◽  
Dark Halo ◽  
Cleavage Stage ◽  
Developmental Arrest ◽  
Inverted Microscope ◽  
Culture Strategies ◽  
Nucleolar Precursor Bodies

SummaryA little studied aspect of developmental arrest (DA) in ART is zygote arrest (ZA). Etiologically, blockage at the first cleavage stage includes molecular and chromosomal anomalies, some of which manifest morphologically. Given considerations on embryo culture, transfer and cryopreservation, optimal zygote selection is very important. The aim of this study was to ascertain whether zygote morphological features were indicators of increased ZA. In this study we performed a prospective, observational study of 2105 zygotes obtained from consecutive patients who were undergoing IVF/ICSI treatment, of which 43 (2%) suffered ZA. Morphological features observed under the inverted microscope were qualitatively categorized: pronuclear size, nucleolar precursor bodies (NPB) alignment, light and dark halos, polar body placement and fragmentation observed at 16–18 h post-insemination. We compared these features in blocked versus cleaved zygotes at 48 h and found significant correlations (p < 0.05) between ZA and three features: the absence of a light halo (p = 0.001), the absence of a dark halo (p < 0.005), and non-aligned NPB (p < 0.05). We can say that certain morphological features are indicators of significantly increased zygote arrest. These findings may be of utility for optimal zygote selection and culture strategies, especially in countries under restrictive conditions.

scholarly journals Evaluating the value of day 0 of an ICSI cycle on indicating laboratory outcome

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
E. Maziotis ◽  
K. Sfakianoudis ◽  
P. Giannelou ◽  
S. Grigoriadis ◽  
A. Rapani ◽  
...  
Keyword(s):  
Observational Study ◽  
Prospective Observational Study ◽  
Embryo Quality ◽  
Polar Body ◽  
Grading System ◽  
Ivf Outcome ◽  
Fertilization Failure ◽  
Live Birth Rates ◽  
Icsi Cycle ◽  
Account Information

Abstract A number of oocyte characteristics have been associated with fertilization, implantation and live-birth rates, albeit without reaching a consensus. This study aims to delineate possible associations between oocyte characteristics, oocyte behavior during intracytoplasmic sperm injection (ICSI), fertilization potential, and laboratory outcomes. Four-hundred and seventy-seven patients, yielding 3452 oocytes, were enrolled in this prospective observational study from 2015 to 2018. Οoplasm granularity was associated with poor embryo quality and higher probabilities of post-ICSI oocytes and embryos discarded in any developmental stage and never selected for embryo transfer or cryopreservation (p < 0.001). Both sudden or difficult ooplasm aspiration, and high or lack of resistance during ICSI were associated with either a poor Zygote-Score or fertilization failure (p < 0.001). Sudden or difficult ooplasm aspiration and high resistance during ICSI penetration were positively associated with resulting to a post-ICSI oocyte or embryo that would be selected for discard. Evaluation of oocyte characteristics and oocyte behavior during ICSI may provide early information regarding laboratory and cycle outcomes. Particularly, ooplasm granularity, and fragmentation of polar body, along with sudden or difficult ooplasm aspiration and high or lack of resistance during ICSI penetration may hinder the outcome of an ICSI cycle. The associations presented herein may contribute towards development of a grading system or a prediction model. Taking into account information on oocytes and ICSI behavior may effectively assist in enhancing IVF outcome rates.

107 Insights from roe deer oocyte transcriptome across embryonic diapause

2019 ◽  
Vol 31 (1) ◽  
pp. 179
Author(s):  
S. M. Bernal-Ulloa ◽  
V. A. van der Weijden ◽  
J. T. Bick ◽  
A. B. Rüegg ◽  
B. Drews ◽  
...  
Keyword(s):  
Gene Ontology ◽  
False Discovery Rate ◽  
Roe Deer ◽  
Expression Profiles ◽  
Polar Body ◽  
Morphological Characteristics ◽  
Reduction Process ◽  
Immature Oocytes ◽  
Developmental Arrest ◽  
False Discovery

Embryonic developmental arrest, known as diapause, has been reported in more than 130 species. However, its mechanisms are still not completely understood. In the roe deer, the only known ungulate that exhibits this phenomenon, diapause lasts for approximately 5 months, starting after the rut period in mid-July to early August and ending with embryo elongation and implantation in December/January. Little is known regarding oocyte characteristics during this period. Here, we analysed the roe deer oocyte transcriptome as a model to understand diapause effects on oocyte features during embryonic developmental arrest and reactivation. During regular hunting, immature oocytes were obtained by ovary slicing from diapause and nondiapause stages, and classified according to morphological characteristics. Only oocytes with &gt;2 layers of compact cumulus cells and cytoplasm from 30 hunted females were used for analyses. Immature oocytes were denuded and snap frozen. Additional oocytes were cultured in maturation medium for 20-24h. Matured oocytes with a present polar body were snap frozen. Two pools of 10 immature and mature oocytes for both diapause and nondiapause stages were included (at least 4 donors/pool). Oocyte pools were processed using the Smart-seq 2 single-cell protocol (Illumina Inc., San Diego, CA, USA) for full-length cDNA and library preparation. We performed RNA-seq on an Illumina sequencer. The obtained Fastq files were clipped and analysed with a locally installed version of the Galaxy platform. Sequences were mapped against the roe deer transcriptome (unpublished data) and annotated against human and bovine transcripts. Differentially expressed genes (DEG; false discovery rate &lt;1%) were identified using EdgeR (https://bioconductor.org/packages/release/bioc/html/edgeR.html) in immature (IMM) and mature (M) oocytes from diapause (D) and nondiapause (ND) stages. Additionally, to evaluate the effects of maturation on oocyte transcript abundancy, DEG between IMM and M oocytes for D and ND were identified. Multidimensional scaling resulted in clustering according to oocyte types. Gene ontology terms for biological processes were assigned using ToppCluster tools. A total of 23066, 23022, 22438, and 22532 transcripts were detected for IMM D, M D, IMM ND and M ND oocytes, respectively. Using false discovery rate filtering, we found 333 and 288 DEG in immature and mature oocytes, respectively. Furthermore, maturation changed the oocyte expression profiles during D (2233 DEG) and ND periods (2589 DEG). Gene ontology classification revealed that most of the DEG in immature oocytes were involved in macromolecule catabolic process and oxidation-reduction process. For mature oocytes, DEG were mostly related to regulation of chromosome condensation and ER and Golgi vesicle-mediated transport. Additionally, the top 20 DEG from IMM D v. M D oocytes were related to mRNA splicing, mRNA metabolic process, and mRNA processing. These processes were not identified in the top 20 DEG from IMM ND v. M ND oocytes. These preliminary results suggest that oocyte transcriptome analysis could disclose new pathways implicated in oocyte competence and embryonic developmental arrest and activation stages.

Thioglycolic acid inhibits mouse oocyte maturation and affects chromosomal arrangement and spindle configuration

2008 ◽  
Vol 24 (4) ◽  
pp. 227-234 ◽  
Author(s):  
SY Hou ◽  
L Zhang ◽  
K Wu ◽  
L Xia
Keyword(s):  
Thioglycolic Acid ◽  
Polar Body ◽  
Germinal Vesicle ◽  
Germinal Vesicle Breakdown ◽  
Chromosomal Arrangement ◽  
First Polar Body ◽  
Inverted Microscope ◽  
Polar Body Formation ◽  
Spindle Elongation

Previous studies have shown that thioglycolic acid (TGA) leads to potential reproductive toxicology. To clarify the exact effects of this compound on reproduction, mice oocytes were treated with different TGA doses. At the end of the culture period, the nuclear status of mice oocytes was assessed under an inverted microscope. After immunofluorescence staining, the chromosomal arrangement and spindle configuration of oocytes were evaluated. The results indicated that TGA decreases the percentage of first polar body formation but does not influence that of germinal vesicle breakdown. TGA induces abnormal chromosomal arrangement and spindle elongation. In conclusion, TGA inhibits in-vitro maturation of mice oocytes and affects chromosomal arrangement and spindle configuration. Furthermore, it probably interferes with biochemical changes that occur during meiosis, resulting in aberrant development.

I7 Polar body sampling, cleavage stage, blastocyst biopsy or combination? Their impact on embryo viability and PGD accuracy

2013 ◽  
Vol 26 ◽  
pp. S3
Author(s):  
N.H. Zech ◽  
M. Zintz ◽  
B. Wirleitner ◽  
M. Schuff ◽  
P. Nováková ◽  
...  
Keyword(s):  
Polar Body ◽  
Cleavage Stage ◽  
Embryo Viability ◽  
Blastocyst Biopsy

The effect of temperature on developmental rates in the nudibranch Cadlina luteomarginata

1979 ◽  
Vol 57 (10) ◽  
pp. 1835-1844 ◽  
Author(s):  
Paul A. Dehnel ◽  
David C. Kong
Keyword(s):  
Polar Body ◽  
Effect Of Temperature ◽  
Shell Formation ◽  
Cleavage Stage ◽  
Temperature Dependent ◽  
Cilia Formation ◽  
Developmental Rates ◽  
Polar Body Formation ◽  
Time Required ◽  
Egg Capsule

Egg masses of the nudibranch Cadlina luteomarginata, which were spawned in the laboratory from adults held at 10 °C, were reared at four experimental temperatures, 5, 10, 15, and 20 °C. To determine the effect of temperature on developmental rates, the time required to develop the following stages or structures at these four temperatures was determined: polar body formation, first cleavage, second cleavage, third cleavage, fourth cleavage, gastrulation, closure of the blastopore, cilia formation, oral invagination, rudiment of the foot, shell formation, ciliation of the foot, statocyst formation, collapse of the egg capsule, and hatching as a veliger. The data show that as the temperature decreases the time required for a particular stage to develop increases. Embryos reared at 20 °C degenerated after the fourth cleavage stage. Total time required to reach the hatching stage (veliger) at the control temperature (10 °C) was 35 days, whereas the time required at 15 °C was 25 days and at 5 °C was 86 days. These data show that development is temperature dependent.

scholarly journals Vitrification of immature oocytes of goats in Bangladesh

2019 ◽  
Vol 35 (1-2) ◽  
pp. 7-12
Author(s):  
MN Sharif ◽  
SM Choudhury ◽  
MM Rahman ◽  
MM Rahman ◽  
NS Juyena ◽  
...  
Keyword(s):  
Culture Medium ◽  
Assisted Reproductive Technologies ◽  
Polar Body ◽  
Cumulus Cells ◽  
Reproductive Technologies ◽  
Step Procedure ◽  
Inverted Microscope ◽  
Maturation Rate ◽  
Humidified Air

Cryopreservation of oocytes and embryos by vitrification can have advantages in assisted reproductive technologies (ARTs) in mammals. The aim of this study was to establish an effective vitrification procedure and cryodevice for goat’s oocytes in Bangladesh. Cumulus oocyte complexes (COCs) were collected from ovaries from slaughterhouse. COCs with more than 3 layers of cumulus cells were selected. COCs were vitrified by two-step procedure using 7.5% and 15% dimethyl sulphoxide (DMSO) as cryoprotective agent (CPA), loaded on Cryotop or French mini-straw, then directly plunged into liquid nitrogen (LN2). Then the COCs containing Cryotop or French mini-straws were warmed in 0.25 M sucrose and 20% FBS-supplemented tissue culture medium (TCM) 199 followed by in vitro culture in 50 μl droplets of bicarbonate-buffered TCM 199 supplemented with 10% FBS, pyruvate, FSH and oestradiol for 24 h at 39°C with 5% CO2 in humidified air. After maturation culture, oocytes were denuded and examined under inverted microscope for presence of polar body as the indication of maturation. The in vitro maturation rate of goat’s oocytes after vitrification and warming was 39.3 ± 6.8%, 31.3 ± 9.4%, 61.6 ± 14.2% when using Cryotop (cryodevice), French mini-straws and without vitrification (control), respectively. Maturation rate was significantly higher (P<0.05) without vitrification. It is suggested that both Cryotop and French mini-straw are efficient cryodevices for vitrification of goat’s oocytes and further investigation is required to optimize the protocol for vitrification and warming procedure for the satisfactory survival of goat’s oocytes. The Bangladesh Veterinarian (2018) 35(1&2): 7-12

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