Embryonic development of a collembolan, Tomocerus cuspidatus Börner, 1909: With special reference to the development and developmental potential of serosa (Hexapoda: Collembola, Tomoceridae)

2015 ◽  
Vol 44 (2) ◽  
pp. 157-172 ◽  
Author(s):  
Shigekazu Tomizuka ◽  
Ryuichiro Machida
Keyword(s):  
Embryonic Development ◽  
Special Reference ◽  
Developmental Potential

196 A NEW APPROACH TO PREDICT MOUSE EMBRYONIC DEVELOPMENTAL COMPETENCE USING A TIME-LAPSE SYSTEM AND THE 'SHORTEST HALF' analysis procedure

2007 ◽  
Vol 19 (1) ◽  
pp. 214 ◽  
Author(s):  
S. Yavin ◽  
A. Aroyo ◽  
Z. Roth ◽  
A. Arav
Keyword(s):  
Embryonic Development ◽  
Time Lapse ◽  
Time Frame ◽  
Blastocyst Stage ◽  
Developmental Competence ◽  
Embryo Morphology ◽  
Cell Stage ◽  
Developmental Potential ◽  
Additional Tool ◽  
Embryonic Cleavage

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

173 HINDERING OF CLEAVAGE TIMING IN BOVINE PARTHENOTES DURING THE HOT SEASON

2007 ◽  
Vol 19 (1) ◽  
pp. 203 ◽  
Author(s):  
A. Aroyo ◽  
S. Yavin ◽  
Z. Roth ◽  
A. Arav
Keyword(s):  
Thermal Stress ◽  
Embryonic Development ◽  
Elevated Temperatures ◽  
Time Lapse ◽  
Cold Season ◽  
Seasonal Effects ◽  
Cell Stage ◽  
Developmental Potential ◽  
Hot Season

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.

Anti-silencing factor 1A is associated with genome stability maintenance of mouse preimplantation embryos†

2020 ◽  
Vol 102 (4) ◽  
pp. 817-827
Author(s):  
Kai Deng ◽  
Wanyou Feng ◽  
Xiaohua Liu ◽  
Xiaoping Su ◽  
Erwei Zuo ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Genome Stability ◽  
Mouse Embryos ◽  
Preimplantation Embryos ◽  
End Joining ◽  
Dna Damages ◽  
Developmental Potential ◽  
Damage Repair ◽  
Non Homologous End Joining ◽  
Early Mouse

Abstract Genome stability is critical for the normal development of preimplantation embryos, as DNA damages may result in mutation and even embryo lethality. Anti-silencing factor 1A (ASF1A) is a histone chaperone and enriched in the MII oocytes as a maternal factor, which may be associated with the maintenance of genome stability. Thus, this study was undertaken to explore the role of ASF1A in maintaining the genome stability of early mouse embryos. The ASF1A expressed in the preimplantation embryos and displayed a dynamic pattern throughout the early embryonic development. Inhibition of ASF1A expression decreased embryonic development and increased DNA damages. Overexpression of ASF1A improved the developmental potential and decreased DNA damages. When 293T cells that had been integrated with RGS-NHEJ were co-transfected with plasmids of pcDNA3.1-ASF1A, gRNA-NHEJ, and hCas9, less cells expressed eGFP, indicating that non-homologous end joining was reduced by ASF1A. When 293T cells were co-transfected with plasmids of HR-donor, gRNA-HR, hCas9, and pcDNA3.1-ASF1A, more cells expressed eGFP, indicating that homologous recombination (HR) was enhanced by ASF1A. These results indicate that ASF1A may be associated with the genome stability maintenance of early mouse embryos and this action may be mediated by promoting DNA damage repair through HR pathway.

scholarly journals Use of retinoids during oocyte maturation diminishes apoptosis in caprine embryos

2015 ◽  
Vol 63 (2) ◽  
pp. 234-242 ◽  
Author(s):  
Juliana C. Z. Conceição ◽  
Marcelo T. Moura ◽  
José C. Ferreira-Silva ◽  
Pamela Ramos-Deus ◽  
Priscila G. C. Silva ◽  
...  
Keyword(s):  
Retinoic Acid ◽  
Embryonic Development ◽  
Blastocyst Stage ◽  
Tunel Assay ◽  
Caspase Activity ◽  
Retinyl Acetate ◽  
Developmental Potential ◽  
Concomitant Reduction ◽  
Lower Capacity

Exposure of caprine oocytes and embryos to retinoids enhances embryonic development, but the mechanisms governing this phenomenon have not been characterised. The aim of the present study was to evaluate if the incidence of apoptosis is affected by the addition of retinyl acetate (RAc) and 9-cis-retinoic acid (RA) during in vitro maturation (IVM) of caprine oocytes. Embryonic development was recorded on days 3 and 8 post-fertilisation, and apoptosis was measured by caspase activity and DNA fragmentation (TUNEL assay). Control zygotes had lower capacity to cleave and reach the blastocyst stage (24.45 ± 2.32 and 5.32 ± 0.81, respectively) than those of RAc- (29.96 ± 1.62 and 7.94 ± 0.93, respectively) and RA-treated groups (30.12 ± 1.51 and 7.36 ± 1.02, respectively). Oocytes and blastocysts positive for TUNEL assay were more frequent, respectively, in the controls (8.20 ± 0.78, 8.70 ± 1.05) than in RAc (5.60 ± 0.52, 4.80 ± 0.51) and RA (6.40 ± 0.69, 5.40 ± 0.69). Caspase activity did not differ between control oocytes (7.20 ± 0.91), RAc (6.60 ± 0.68) and RA (7.30 ± 0.67), but it was reduced in RAc- (5.05 ± 0.62) and RA-treated blastocysts (5.75 ± 0.22) compared to controls (8.35 ± 0.71). These results indicate that the addition of retinoids during IVM increases the developmental potential of goat embryos with a concomitant reduction in apoptosis rates.

Embryonic development of Zoraptera with special reference to external morphology, and its phylogenetic implications (Insecta)

2013 ◽  
Vol 275 (3) ◽  
pp. 295-312 ◽  
Author(s):  
Yuta Mashimo ◽  
Rolf G. Beutel ◽  
Romano Dallai ◽  
Chow-Yang Lee ◽  
Ryuichiro Machida
Keyword(s):  
Embryonic Development ◽  
Special Reference ◽  
External Morphology ◽  
Phylogenetic Implications

scholarly journals Transcriptional profile of bovine preimplantation development selected based on G6PDH activity

2021 ◽  
Vol 5 (1) ◽  
pp. 001-003
Author(s):  
Ghanem Nasser ◽  
Samy Romysa ◽  
Kassab Eman Kh ◽  
Khalil Beshoy SF ◽  
Kordy Aya Ahmed ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Genetic Material ◽  
Implantation Rate ◽  
Short Review ◽  
Oocyte Quality ◽  
Blastocyst Stage ◽  
Blue Staining ◽  
G6pdh Activity ◽  
Cell Stage ◽  
Developmental Potential

The oocyte is the female gamete that contributes not only half of the genetic material but also all of the cytoplasm to the zygote, supplying the transcripts, proteins, mitochondria and other components necessary for early embryonic development. The intrinsic oocyte quality is one of the main factors affecting the embryo yield, the implantation rate and the rate of healthy offspring. It is obvious that a fertilized oocyte must reach the blastocyst stage within 6–9 days in the proper culture conditions to have a significant chance of inducing a pregnancy and producing an offspring. The ability to sustain the first week of embryonic development is clearly influenced by the follicular status from which the oocyte is obtained indicating that this developmental potential is inherent within certain oocytes. Since most early embryos that do not reach the blastocyst stage are blocked at or close to the maternal to zygotic transition (MZT)-stage, which occurs at the eight-cell stage in cattle, one could speculate that incompetent oocytes fail to appropriately activate the embryonic genome. Oocyte selection based on glucose-6-phosphate dehydrogenase (G6PDH) activity has been successfully used to differentiate between competent and incompetent bovine oocytes. Recently, molecular regulation of genes regulating biological process of Brilliant Cresyl Blue staining (BCB) selected oocytes and embryos was investigated to explain their variation in quality and developmental potentiality. This short review will highlights some of these efforts that have been done in this interesting area of research.

scholarly journals Epigenetics, embryo quality and developmental potential

2015 ◽  
Vol 27 (1) ◽  
pp. 53 ◽  
Author(s):  
Nathalie Beaujean
Keyword(s):  
Dna Methylation ◽  
Embryonic Development ◽  
Embryo Quality ◽  
Epigenetic Modifications ◽  
Intimate Contact ◽  
Developmental Potential ◽  
Post Translational Modifications ◽  
Oocyte Cytoplasm ◽  
Epigenetic Signatures ◽  
Further Development

It is very important for embryologists to understand how parental inherited genomes are reprogrammed after fertilisation in order to obtain good-quality embryos that will sustain further development. In mammals, it is now well established that important epigenetic modifications occur after fertilisation. Although gametes carry special epigenetic signatures, they should attain embryo-specific signatures, some of which are crucial for the production of healthy embryos. Indeed, it appears that proper establishment of different epigenetic modifications and subsequent scaffolding of the chromatin are crucial steps during the first cleavages. This ‘reprogramming’ is promoted by the intimate contact between the parental inherited genomes and the oocyte cytoplasm after fusion of the gametes. This review introduces two main epigenetic players, namely histone post-translational modifications and DNA methylation, and highlights their importance during early embryonic development.

230 ROLE OF PITUITARY HORMONES AND CUMULUS CELLS IN MODULATING THE DEVELOPMENTAL CAPACITY OF AGING BOVINE OOCYTES

2015 ◽  
Vol 27 (1) ◽  
pp. 204
Author(s):  
G. Singina ◽  
I. Lebedeva ◽  
T. Taradajnic ◽  
N. Zinovieva
Keyword(s):  
Embryonic Development ◽  
Tyrosine Kinases ◽  
Cumulus Cells ◽  
Pituitary Hormones ◽  
Developmental Competence ◽  
Developmental Potential ◽  
Prolonged Culture ◽  
Bovine Oocytes

The competence for embryonic development acquired during the oocyte maturation attenuates during the subsequent oocyte aging both in vivo and in vitro. Thus, the successful control of the female fertility requires information regarding factors responsible for the oocyte protection from early aging. The aim of the present research was to study the pattern and pathways of actions of two closely related pituitary hormones, prolactin (PRL), and growth hormone (GH), on the developmental potential of bovine oocytes during their aging in vitro. Therefore, we analysed (1) effects of PRL and GH during the prolonged culture of bovine oocytes on their subsequent development up to the blastocyst stage and (2) the role of cumulus cells (CC) and tyrosine kinases, the well-known mediators of PRL and GH signalling, in these effects. Bovine cumulus-enclosed oocytes (CEO) were cultured for 22 h in the following maturation medium: TCM 199 containing 10% fetal calf serum (FCS), 10 μg mL–1 of porcine FSH, and 10 μg mL–1 of ovine LH. After IVM, CEO or denuded oocytes (DO) were transferred to the aging medium consisting of TCM 199 supplemented with 10% FCS and cultured for 10 h in the absence (Control) or presence of 50 ng mL–1 bovine PRL or 10 ng mL–1 recombinant bovine GH and/or 10 μg mL–1 genistein (a non-selective inhibitor of tyrosine kinases). Genistein was not applied in the case of aging DO, since their developmental potential was not affected by both hormones. Following the prolonged culture, oocytes underwent IVF and IVC. Embryos were cultured in CR1aa medium until Day 5 post-insemination and then transferred to the same medium supplemented with 5% FCS and cultured up to Day 8. The embryo development was evaluated at Days 2 and 8 for cleavage and blastocyst formation. The data from 5 to 6 replicates using 135–184 oocytes per treatment were analysed by ANOVA. Aging of oocytes in the control medium had no effect on the cleavage rate, but caused the blastocyst yield to decline (P < 0.001) from 31.1 ± 2.3% (CEO fertilized immediately after maturation) to 10.5 ± 2.4% (aged CEO) and 7.9 ± 1.9% (aged DO). Cleavage rates of aging CEO and DO were unaffected by both PRL and GH. In the case of CEO, the addition of PRL (but not GH) to the aging medium raised the blastocyst yield from 8.2 ± 0.9% to 15.2 ± 2.1% (P < 0.05), whereas the removal of CC abolished this effect, reducing the yield up to 9.1 ± 2.7% (P < 0.05). At the same time, genistein did not influence the blastocyst yield in the PRL-treated group. The findings demonstrate that PRL can inhibit the attenuation of the developmental competence of bovine oocytes aging in vitro, with this effect being achieved via cumulus cells. Tyrosine kinases are unlikely to mediate the beneficial action of PRL on the CEO capacity for embryonic development. Meanwhile, closely related GH does not affect the developmental competence of aging bovine oocytes.This research was supported by RFBR (project No. 13-04-01888).

155 EFFECT OF CO-CULTURE WITH CUMULUS-DERIVED SOMATIC CELLS DURING IN VITRO MATURATION ON PORCINE CUMULUS–OOCYTE COMPLEXES AND SUBSEQUENT EMBRYONIC DEVELOPMENT AFTER IN VITRO FERTILIZATION

2014 ◽  
Vol 26 (1) ◽  
pp. 191 ◽  
Author(s):  
J. D. Yoon ◽  
L. Cai ◽  
S. U. Hwang ◽  
Y. Jeon ◽  
E. Kim ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Mrna Expression ◽  
In Vitro Maturation ◽  
Somatic Cells ◽  
The Other ◽  
Control Group ◽  
Cortical Granules ◽  
Developmental Potential ◽  
Significant Difference

The purpose of this study was to investigate the effects of co-culture with cumulus-derived somatic cells (CSC) during porcine in vitro maturation (IVM) and subsequent embryonic development after IVF. The CSC were cultured in Dulbecco's modified Eagle medium for 48 h with various numbers of cumulus-derived somatic cells (0.0, 2.5, 5.0, and 10.0 × 104), and then cultured in TCM-199 for 4 h before the oocytes were added. Cumulus-oocytes complexes from 3- to 6-mm follicles were matured in 500 μL of TCM-199, with eCG and hCG, for 22 h, and then cultured in M199 without hormones for 22 h. Each experiment consisted of at least 4 replicates. Statistical analyses were carried out using SPSS 17.0 software (SPSS Inc., Chicago, IL). Percentage data were compared by one-way ANOVA, followed by Duncan's multiple range test. Data were presented as means ± s.e.m. Differences were considered to be significant if the P-value was 0.05. After IVM, no significant difference (P < 0.05) was observed in nuclear maturation rate among the 0.0, 2.5, 5.0, and 10.0 × 104 groups (88.0 ± 2.37, 81.5 ± 2.17, 87.0 ± 1.98 and 86.0 ± 1.93%, respectively). The 2.5 × 104 group showed a significant (P < 0.05) increase in intracellular glutathione (GSH) levels compared with that of the other groups. Intracellular reactive oxygen species (ROS) levels of mature oocyte in all groups showed no significant differences. The developmental competence of matured oocytes in all groups was evaluated after IVF. The 2.5 and 5.0 × 104 groups showed significantly (P < 0.05) high cleavage rates (60.0 ± 4.7 and 64.52 ± 5.9%, respectively) compared with the 0 and 10.0 × 104 groups (43.15 ± 5.0 and 53.8 ± 5.0%, respectively). The 2.5 × 104 group showed a significantly (P < 0.05) higher BL formation rate (35.7 ± 2.9) than control group (21.0 ± 3.8%, respectively), and higher total cell number (127.25 ± 7.7) compared with the 0 and 10 × 104 groups (89.3 ± 4.0 and 92.6 ± 3.7, respectively). In the analysis of gene expression, IVF-BL derived from the 2.5 and 5.0 × 104 groups showed higher (P < 0.05) mRNA expression of PCNA, which is an essential component of the DNA replication and repair machinery and POU5F1 has been used to evaluate developmental potential in embryos. The 10.0 × 104 group showed higher (P < 0.05) mRNA expression of caspase-3 and Bak as known pro-apoptotic factors, compared with the control group IVF-BL. The results of cortical granules distribution which leads digesting sperm receptor proteins ZP2 and ZP3 to block polyspermy, showed that the 2.5 × 104 group was increased significantly (P < 0.05) compared with the other co-culture groups (13.7 ± 6.1, 29.2 ± 9.5, 18.3 ± 0.8 and 19.52 ± 5.3, respectively). In conclusion, co-culture with 2.5 × 104 cumulus-derived somatic cells during IVM improved the developmental potential of porcine IVF embryos by increasing the intracellular GSH level and distribution of cortical granules during oocyte maturation. This work was supported, in part, by a grant from the Next-Generation BioGreen 21 Program (No. PJ00956901), Rural Development Administration, and the National Research Foundation of Korea Grant funded by the Korean Government (NRF-2012R1A1A4A01004885, NRF-2013R1A2A2A04008751), Republic of Korea.

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