Dynamic Morphology of the Human Ooplasm and Subsequent Embryonic Development Analyzed by Time-Lapse Cinematography

2015 ◽  
Vol 32 (4) ◽  
pp. 143-148
Author(s):  
Kyoko Iwata ◽  
Keitaro Yumoto ◽  
Jiroh Yamauchi ◽  
Yumiko Iba ◽  
Yasuyuki Mio
2014 ◽  
Vol 102 (3) ◽  
pp. e19-e20 ◽  
Author(s):  
D. Ben-Yosef ◽  
L. Bar-El ◽  
T. Shwartz ◽  
T. Cohen ◽  
A. Carmon ◽  
...  

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
A NAGANO ◽  
Y Narumiya ◽  
N Okutani ◽  
S Mizuta ◽  
T Takeuchi ◽  
...  

Abstract Study question Does direct unequal cleavage (DC) affect embryonic development after ICSI with testicular sperm (TESE-ICSI) in patients with non-obstructive azoospermia (NOA) and/or obstructive azoospermia (OA)? Summary answer The incidence of DC at the first cleavage (DC1) was extremely high and DC1 negatively affected embryonic development in NOA patients. What is known already It has been reported that the blastocyst development of embryos with direct cleavage (DC) was significantly lower than that without DC, but the clinical pregnancy rate after blastocyst transfer was not different with or without DC. The incidence of DC has been reported to be significantly higher after ICSI with testicular sperm (TESE-ICSI) than ICSI with ejaculated sperm (Ej), but to our knowledge, there are few reports investigating that the embryos with DC after TESE-ICSI affect embryonic development. Study design, size, duration We conducted a retrospective cohort study using time-lapse incubators (Geri, Genea Biomedx, Australia) from September 2018 to November 2020. Of 1033 two-pronuclear (2PN) embryos from TESE-ICSI, 486 and 547 embryos were from OA (35.9±5.5 years) and NOA (33.7±5.2 years), respectively. As an age matched control, we chose 581 embryos from ICSI using Ej (36.5±4.4 years). Participants/materials, setting, methods DC embryos were classified as DC1 (DC at first cleavage), DC2 (DC at second cleavage), and non-DC (without DC). The incidences of DC1 or DC2 and blastocyst development rates were compared among OA, NOA and Ej groups. In TESE-ICSI group, we compared blastocyst development rates with or without DC between good and poor quality embryos on day 3. Good quality embryos were defined as 8 cells with G3 or more by the Veeck’s classification. Main results and the role of chance DC1 incidence was significantly higher in NOA (37.3%) than OA (27.8%) and Ej (22.7%) (P < 0.01), whereas DC2 incidence was not statistically different among three groups; NOA (15.7%), OA (15.0%) and Ej (13.4%). Blastocyst development rates in DC1 were 17.8%, 19.5% and 25.8% for NOA, OA and Ej, respectively, which were significantly lower compared to non-DC in corresponding three groups (65.1%, 67.7%, and 68.5%, respectively, P < 0.01). In TESE-ICSI group, good-quality embryo rate on day 3 was significantly lower in DC1 (34.5%, P < 0.01) than DC2 (60.9%) or non-DC (54.2%). Additionally, blastocyst development rates in DC1 and DC2 were significantly lower than non-DC regardless of embryonic grades on day 3 (35.1%, 51.0%, and 81.6% for good-quality embryos on day 3, 10.1%, 27.0%, and 49.1% for poor-quality embryos on day 3, respectively, P < 0.05). When immotile sperm was used for TESE-ICSI, DC1 incidence was 40.0% (6/15), which did not show statistically differences. When performing single frozen-thawed blastocyst transfers, no pregnancies resulted from either DC1 (n = 13) or DC2 (n = 3) embryos in TESE-ICSI group. Limitations, reasons for caution We had a few data about the pregnancy rates after blastocyst transfers with DC, because embryos with DC were seldom transferred due to those lower priority. Although DC might be influenced by the sperm, we did not analyze the incidence of DC by taking the semen factors into account. Wider implications of the findings: The incidence of DC1 was extremely high and DC1 negatively affected embryonic development in NOA patients. Therefore, it is important to observe embryos using time-lapse incubator in order to recognize embryos with/without pregnancy potential, especially for embryos with DC1 in NOA patients. Trial registration number Not applicable


2007 ◽  
Vol 19 (1) ◽  
pp. 214 ◽  
Author(s):  
S. Yavin ◽  
A. Aroyo ◽  
Z. Roth ◽  
A. Arav

Embryonic development is a dynamic process in which embryo morphology may change immensely within several hours. Therefore, identifying and selecting embryos with the highest probability of developing and achieving a pregnancy is a major challenge. The timing of embryonic cleavage may serve as an additional indicator for the identification of quality embryos. The aim of this study was to characterize the cleavage timing of mouse embryos and to identify the stage that is most indicative of blastocyst formation. Mated mice (CB6F1) were sacrificed 20 h after hCG administration; putative zygotes were recovered and cultured (50 embryos in each 20-µL drop of M16) in a time-lapse system (EmbryoGuard; IMT, Ltd., Ness-Ziona, Israel) inside the incubator. The time-lapse system was programmed to take photos at half-hour intervals such that culture dishes were not removed from the incubator. The ‘shortest half’ statistical procedure of JMPIN (SAS Institute, Inc., Cary, NC, USA) was utilized to evaluate the period during which at least 50% of the embryonic population cleaves within the shortest time frame. Captured images made it possible to search along the time axis for the densest 50% of cleavage observations. Developing embryos were categorized into 3 groups according to the time of cleavage after hCG administration: before, during, and after the ‘shortest half’ for each developmental stage. Two hundred thirty putative zygotes cleaved and created 2-cell-stage embryos, of which 55 arrested at various stages and 175 progressed to the blastocyst stage. During embryonic development, cleavage timing appeared to become less uniform and the ‘shortest half’ became longer for each successive cell division: Whereas the shortest period in which 50% of the 2-cell-stage embryos cleaved was a 2-h interval, cleavage into the 4-cell, 8-cell, and blastocyst stages took 2.5, 3.5, and 5 h, respectively. The ‘short half’ for the first cleavage appears to be a predictive time frame for subsequent embryonic development, because cleavage was closely synchronized with 80% of the embryos developing to the blastocyst stage. Note that only a small number of embryos were actually cleaving early, while the ‘shortest half’ consisted of 50% of the embryonic population. Moreover, late-cleaving embryos in the 2-cell stage expressed inferior developmental potential relative to those that cleaved within the ‘shortest half’ (see Table 1). In summary, 2-cell-stage embryos that cleaved within the ‘shortest half’ seemed to be better synchronized and consequently more competent than the rest of the embryonic population. Embryonic cleavage timing using the ‘shortest half’ parameter can be considered a biological indicator of embryo potential. It may be useful as an additional tool for selecting embryos for transfer and cryopreservation. Table 1. Cleavage timing distribution into the 2-cell stage according to the shortest half


2007 ◽  
Vol 19 (1) ◽  
pp. 203 ◽  
Author(s):  
A. Aroyo ◽  
S. Yavin ◽  
Z. Roth ◽  
A. Arav

Heat stress is a major contributing factor to low fertility among dairy cattle, as reflected by the dramatic reduction in conception rate during the hot months. The effects of thermal stress on oocyte competence and embryonic development have been well documented. However, timing of embryonic cleavage, which may be considered a parameter for the identification of good-quality embryos, and its association with elevated temperatures have not been studied. Two experiments were performed to examine and characterize seasonal effects (i.e. thermal stress) on cleavage timing of bovine parthenogenetic embryos. Oocytes were aspirated from ovaries collected at the local abattoir in 2 seasons: cold (Dec–Apr) and hot (May–Nov). Matured oocytes were chemically activated (ionomycin followed by 6-DMAP) and cultured in vitro; cleavage timing to the 2- and 4-cell stages was observed and documented. The one-way ANOVA procedure was used for statistical analysis. In the first experiment (n = 5416 oocytes), cleavage was documented at specific time points during development post-activation. The peak in embryonic development to the 2-cell stage was earlier (22 to 27 vs. 27 to 40 h after activation) and the cleavage rate higher (39 vs. 21%; P < 0.0001) during the cold season relative to the hot season, respectively. Similarly, the peak in 4-cell-stage development was also observed earlier (46–52 vs. 52–70 h after activation) and corresponded with a higher proportion of developing embryos (33 vs. 21%; P < 0.0001) during the cold season as compared to the hot season, respectively. These results indicate that embryonic development is delayed and a lower proportion of embryos cleaved during the hot season. To better understand the delay in cleavage timing, a second experiment (n = 308 oocytes) was performed through two consecutive hot seasons. A time-lapse system (EmbryoGuard; IMT, Ltd., Ness-Ziona, Israel) was employed to collect accurate data on the first cleavage division, known to be indicative of embryo quality. The time-lapse system was pre-programmed to take photos at 1-h intervals such that culture dishes did not need to be removed from the incubator. Similar to the pattern noted for the hot season in the first experiment, a wide distribution of cleavage timing (18-40 h after activation) was observed. Further analysis revealed that embryos cleaved in 2 distinct waves: cleavage timing of the first wave (18 to 25 h after activation) was characterized by a time frame similar to that in the cold season, suggesting good-quality embryos; however, the second wave, from 27 to 40 h after activation, presented a delay in cleavage timing, suggesting that these late-cleaving embryos are of inferior quality. Taken together, the results of the 2 experiments lead to the assumption that oocytes harvested from lactating cows during the hot season are of reduced developmental potential, which may be explained, in part, by the pattern of 2 cleavage waves. Furthermore, cleavage timing appears to be a good indicator of embryo potential and may increase the chances of selecting better in vitro-derived embryos during the hot season for embryo transfer.


1978 ◽  
Vol 56 (7) ◽  
pp. 1540-1545 ◽  
Author(s):  
Paul Sussman ◽  
T. W. Betz

A Staged series (n = 25–476} with time data for Bombina orientalis embryonic development is presented. Stages for Bombina and Rana pipiens seem identical except that approximately 50% of opercular closures are symmetrical in Bombina. Counting numbers of embryos at a stage at regular intervals allowed mathematical interpolation of the average time of stage change. A single systematic curve fit the average time per stage of embryonic development, while the increase with time in variance per stage of development was primarily linear. It is possible that the increasing complexity of morphological interstage changes causes increases in the interstage interval and variance per stage over time. The reported method of arriving al a staged series for a previously undocumented species seems more efficient than time-lapse photography. The unusually easy maintenance and dependability or Bombina, contrasting with some amphibians, suggest its use where others have been less practical.


2021 ◽  
Vol 29 (1) ◽  
pp. 9-19
Author(s):  
Oksana V. Shurygina ◽  
Ol'ga Yu. Vasilenko ◽  
Sergey N. Yukhimets ◽  
Nikita A. Shipulin

Despite advances in assisted reproductive technologies, the high failure rate of existing stimulation protocols remains a key industry challenge. One of the leading reasons for this is the limited ability to assess the biological potential of the embryo and its chances of implantation. Over the past ten years, the focus of attention in reproductive technologies has significantly shifted from the patient to the embryo, since the need to improve their effectiveness stimulates the need to understand the deep processes of early development of the embryo. In order to increase the effectiveness of in vitro fertilization procedures in clinical embryology, high-tech methods of culturing and evaluating embryos are being introduced and improved. The purpose of the review is to demonstrate the history, possibilities and prospects in the study of early human embryonic development of time-lapse imaging technology. The active study and use of the capabilities of the time-lapse slow-motion technology allowed not only to expand the understanding of the processes of early development of the embryo, but also at the current moment allows us to assess its potential from the point of view of both biological and clinical perspectives. The main advantages of this method are the possibility of morphological assessment during the continuous cultivation of embryos in closed-type incubators without their extraction, as well as the determination of the exact time intervals of key events of the stages of embryo development with special attention to those moments that are not available for observation and fixation under conditions of traditional cultivation. clinical practice. The main point of growth for the development of time-lapse imaging technology was the creation and validation of the so-called morphokinetic criteria and algorithms for assessing the quality of developing embryos. The key perspective of the method is its use in combination with elements of artificial intelligence in order to predict the most potential embryo for transfer into the uterine cavity. Modern directions of research using the method of time-lapse shooting are the continuation of the development of morphokinetic algorithms and their effective criteria, the introduction of the technology of self-learning computer programs and the adaptation of these tools in clinical practice, the search and assessment of possible factors influencing the morphokinetics of embryos, quality control of the work of embryological laboratories. The future development of such technologies is presented in combination not only with the capabilities of artificial intelligence, but also in combination with the use of non-invasive genetic screening, the assessment of metabolomics and proteomics of developing embryos.


2017 ◽  
Vol 62 (No. 3) ◽  
pp. 121-129 ◽  
Author(s):  
H. Güralp ◽  
K. Pocherniaieva ◽  
M. Blecha ◽  
T. Policar ◽  
M. Pšenička ◽  
...  

Pikeperch Sander lucioperca is a valuable fish in Europe, and basic information about its embryonic development, especially primordial germ cell (PGC) migration, is important for use in biotechnology. We categorized pikeperch embryonic development into six stages as in other fish species: zygote, cleavage, blastula, gastrula, segmentation, and hatching and described PGC migration. PGCs were visualized by injection of synthesized green fluorescent protein (GFP) within the 3’untranslated region (UTR) mRNA of nanos3. GFP-positive PGCs appeared in all embryos at approximately 100% epiboly. Time-lapse imaging revealed the PGC migration pattern from their initial appearance to location at the gonadal ridge. We conducted blastomere transplantation (BT) at the blastula stage. Donor embryos were labelled with GFP-nos3 3’UTR mRNA and tetramethylrhodamine dextran to label PGCs and somatic cells, respectively. Twelve BT chimeras were produced, with eight surviving to hatching. All exhibited donor-derived somatic cells in the developing body. The PGCs from donor embryos were observed to migrate towards the gonad region of the host embryos. Our results indicated that BT can be successfully applied in pikeperch, and these findings may be useful to produce germline chimeras in percids.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
K Yumoto ◽  
T Shimura ◽  
M Sugishima ◽  
M Nakaoka ◽  
Y Mio

Abstract Study question Was embryonic development affected by the degree of perivitelline space (PS) at the pronuclear stage in human zygotes? Summary answer Zygotes with a fully surrounding PS showed less cytoplasmic fragmentation and a higher blastocyst development rate (BDR) than zygotes with a partially surrounding PS. What is known already We previously used abnormally-fertilized oocytes (zygotes with three pronuclei; 3PN), donated by ART patients in our clinic who gave written consent for the research. The zona pellucida (ZP) was artificially removed from these oocytes at the pronuclear stage, termed ZP-free culture. The resultant ZP-free 3PN embryos showed less cytoplasmic fragmentation and a higher rate of good-quality embryos (GQE) compared with ZP-intact embryos. Furthermore, in our clinical setting, the rate of GQE and BDR of normally-fertilized embryos were clearly improved by ZP-free culture in patients with recurrent failure of ART treatments due to severe cytoplasmic fragmentation at the early cleavage stage. Study design, size, duration This study included 49 patients who gave written informed consent for our study and were treated with ART in our clinic between March and December 2020. Embryonic development was compared between zygotes with a fully surrounding PS [PS(+)] with those with a partially surrounding PS [PS(-)] at the pronuclear stage. Furthermore, the ZP of PS(-) embryos were artificially removed at the pronuclear stage, and the rate of GQE and BDR were compared with ZP-intact embryos. Participants/materials, setting, methods The degree of PS in 128 zygotes was confirmed by hypertonic preparation using 0.125M sucrose-containing HEPES medium. PS(+) and PS(-) embryos were both cultured as ZP-intact, and the rate of GQE was compared. Furthermore, 223 zygotes were divided into three groups: 1) PS(-)/ZP-intact, 2) PS(-)/ZP-free, and 3) PS(+)/ZP-intact, and cultured in an incubator equipped with time-lapse monitoring up to Day 7, and the rate of GQE, BDR and useable embryos were compared between each groups. Main results and the role of chance The degree of PS was confirmed by a hypertonic preparation (shrinkage of the ooplasm) in 128 normally-fertilized zygotes obtained from 44 cases. There were 86 PS(-) (67.2%) and 42 PS(+) (32.8%) zygotes. The mean maternal age was 35.9 in PS(-) and 40.5 in PS(+) (P < 0.01), and the rate of GQE was significantly higher in PS(+) [64.3% (27/42)] than in PS(-)[38.4% (33/86)] (P < 0.01). In addition, of 223 normally-fertilized zygotes obtained from 41 cases, there were 51 PS(-)/ZP-intact (Group 1), 132 PS(-)/ZP-free (Group 2) and 40 PS(+)/ZP-intact (Group 3) zygotes. The rate of GQE was significantly lower in Group 1 [29.4% (15/51)] compared with Group 2 [59.8% (79/132)] and Group 3 [62.5% (25/40)] (P < 0.01). BDR was also significantly lower in Group 1 [51.3% (10/39)] compared with Group 2 [75.0% (99/132)] and Group 3 [65.0% (13/20) (P < 0.01). Limitations, reasons for caution Although the artificial removal of ZP at the pronuclear stage (ZP-free culture) clearly increased the rate of GQE, embryonic development was not improved in all cases. It seems that this procedure is only effective in embryos with a viable ooplasm. Wider implications of the findings: The degree of PS at the pronuclear stage affects subsequent embryonic development in human zygotes. The artificial removal of ZP at the pronuclear stage (ZP-free culture) helps to suppress fragmentation and leads to an increase in GQE and BDR, and eventually, improves pregnancy rate in cases with severe fragmentation. Trial registration number non


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