scholarly journals Foetal and Placental Growth in the Mouse After Pre-implantation Development in Vitro Under Oxygen Concentrations' of 5 and 20%

1979 ◽  
Vol 32 (3) ◽  
pp. 363 ◽  
Author(s):  
Gaye M Harlow ◽  
P Quinn
Keyword(s):  
Oxygen Concentration ◽  
Mouse Embryos ◽  
Foster Mothers ◽  
Development In Vitro ◽  
Blastomere Number ◽  
Oxygen Concentrations

Blastocysts which developed from two-cell mouse embryos in culture tubes containing an atmosphere with 20 % oxygen had approximately 20 % fewer blastomeres than blastocysts which developed under an oxygen concentration of 5 %. When these smaller blastocysts were transferred to the uteri of pseudopregnant foster mothers, the foetuses developing were as viable as those developing from blastocysts cultured under 5 % oxygen, indicating their ability to regulate for a lower blastomere number by at least day 17 of development.

Viability and growth of mouse embryos after in vitro culture and fusion

Development ◽  
1970 ◽  
Vol 23 (3) ◽  
pp. 693-704
Author(s):  
Patricia Bowman ◽  
Anne McLaren
Keyword(s):  
In Vitro Culture ◽  
Success Rate ◽  
Zona Pellucida ◽  
Growth Regulation ◽  
Excess Mortality ◽  
Blastocyst Stage ◽  
Mouse Embryos ◽  
Foster Mothers ◽  
Mouse Eggs

About 80 % of 8-cell mouse eggs developed to the blastocyst stage in culture, whether the zona pellucida was left intact, or removed with pronase (pre-incubated and dialysed) and the eggs then cultured singly or as fused pairs. When pronase was used without prior incubation and dialysis, the success rate was reduced to 50 %. After transfer to uterine foster-mothers, 20–30 % of apparently normal blastocysts cultured with or without the zona, singly or fused, developed into live foetuses, compared with over 50 % of control blastocysts taken directly from the uterus. Some of the excess mortality of cultured embryos took place before implantation and some soon after. The foetuses derived from cultured blastocysts averaged 0·1 g lighter than those derived from control uterine blastocysts similarly transferred. No differences in the weights of the placentae were observed. Foetal and placental weights were unaffected by whether the eggs had been cultured singly or fused, implying that growth regulation of fused embryos is complete by the 17th day of gestation. The longer the eggs were maintained in culture, the lower was their viability after transfer, and the lighter were the foetuses derived from them.

scholarly journals The FLASH effect depends on oxygen concentration

2020 ◽  
Vol 93 (1106) ◽  
pp. 20190702 ◽  
Author(s):  
Gabriel Adrian ◽  
Elise Konradsson ◽  
Michael Lempart ◽  
Sven Bäck ◽  
Crister Ceberg ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Underlying Mechanism ◽  
Oxygen Depletion ◽  
Therapeutic Window ◽  
High Dose ◽  
Dose Rates ◽  
Conventional Dose ◽  
Oxygen Concentrations

Objective: Recent in vivo results have shown prominent tissue sparing effect of radiotherapy with ultra-high dose rates (FLASH) compared to conventional dose rates (CONV). Oxygen depletion has been proposed as the underlying mechanism, but in vitro data to support this have been lacking. The aim of the current study was to compare FLASH to CONV irradiation under different oxygen concentrations in vitro. Methods: Prostate cancer cells were irradiated at different oxygen concentrations (relative partial pressure ranging between 1.6 and 20%) with a 10 MeV electron beam at a dose rate of either 600 Gy/s (FLASH) or 14 Gy/min (CONV), using a modified clinical linear accelerator. We evaluated the surviving fraction of cells using clonogenic assays after irradiation with doses ranging from 0 to 25 Gy. Results: Under normoxic conditions, no differences between FLASH and CONV irradiation were found. For hypoxic cells (1.6%), the radiation response was similar up to a dose of about 5–10 Gy, above which increased survival was shown for FLASH compared to CONV irradiation. The increased survival was shown to be significant at 18 Gy, and the effect was shown to depend on oxygen concentration. Conclusion: The in vitro FLASH effect depends on oxygen concentration. Further studies to characterize and optimize the use of FLASH in order to widen the therapeutic window are indicated. Advances in knowledge: This paper shows in vitro evidence for the role of oxygen concentration underlying the difference between FLASH and CONV irradiation.

scholarly journals Oxygen concentration alters mitochondrial structure and function in in vitro fertilized preimplantation mouse embryos

2020 ◽  
Vol 35 (6) ◽  
pp. 1476-1476
Author(s):  
Manuel Belli ◽  
Ling Zhang ◽  
Xiaowei Liu ◽  
Annemarie Donjacour ◽  
Elena Ruggeri ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Structure And Function ◽  
Mouse Embryos ◽  
Mitochondrial Structure ◽  
Preimplantation Mouse Embryos ◽  
Preimplantation Mouse ◽  
And Function

Potential of two-cell mouse embryos to develop to term despite partial damage after cryopreservation

1995 ◽  
Vol 29 (3) ◽  
pp. 320-326 ◽  
Author(s):  
Th. Rülicke ◽  
P. Autenried
Keyword(s):  
Inner Cell Mass ◽  
Cell Mass ◽  
Blastocyst Stage ◽  
Mouse Embryos ◽  
Cell Stage ◽  
Freeze Thaw ◽  
Foster Mothers ◽  
Vital Stains ◽  
Partial Damage

Approximately 18% of cryopreserved 2-cell mouse embryos of 26 different batches showed various degrees of morphological damage after the freeze-thaw process. Normal and damaged morphology were assessed by light microscopy and the ability of an embryo to develop in vitro to a blastocyst, or to develop to term, after transfer to foster mothers. Using vital stains such as Fluorescein-diacetate (FDA) and 4',6-Diamidino-2-Phenylindole (DAPI) it was found that in approximately 82% of the cases, both of the 2 blastomeres of the cryopreserved embryos survived the freeze-thaw process; in 10% only one cell survived the process; and in 8% none survived. Normally, only intact 2-cell embryos are considered for transfer. Here it was shown that over 60% of the partially damaged embryos developed in vitro to the blastocyst stage and, of those, 26% developed to term after transfer to suitable foster mothers. Although the inner cell mass (ICM) appeared to remain smaller during culture after the transfer of partially damaged 2-cell stage embryos, no difference during gestation period was found compared with intact embryos.

Embryonic disc development and subsequent viability of cattle embryos following culture in two media under two oxygen concentrations

2004 ◽  
Vol 16 (8) ◽  
pp. 787 ◽  
Author(s):  
A. E. Fischer-Brown ◽  
B. R. Lindsey ◽  
F. A. Ireland ◽  
D. L. Northey ◽  
R. L. Monson ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Latin Square ◽  
Bovine Embryos ◽  
Morphological Evaluation ◽  
Embryonic Disc ◽  
Developmental Capacity ◽  
Series Of Experiments ◽  
Oxygen Concentrations

Bovine embryos were produced in vitro using a 2 × 2 design of modified medium (KSOM or SOF) and oxygen concentration (5% or 20%). Day 7 blastocysts were transferred in bulk (n = 11, on average) to recipient heifers and recovered non-surgically at Day 14. In two replications of a Latin square, eight heifers received embryos from each combination of factors. Recovered embryos were evaluated for trophoblast length and width, as well as the presence and diameter of an embryonic disc (ED). An ED was detected in a higher percentage of embryos that had been cultured in KSOM than SOF (72% v. 46%, respectively; P < 0.05). The aim of a second series of experiments was to associate Day 14 morphology with subsequent developmental capacity. In vitro-produced blastocysts were transferred (n = 17–20) on Day 7 to each of eight heifers and recovered at Day 14. Thirty-eight blastocysts were retransferred to heifers following morphological evaluation. Embryos in which an ED with no signs of degeneration had been detected maintained more pregnancies than other embryos in which an ED had either shown signs of degeneration or had not been detected (5/8 v. 2/30, respectively; P < 0.01). Further investigation into ED integrity at the elongating stage may contribute to our understanding of pregnancy establishment and maintenance.

Effects of oxygen concentrations on developmental competence and transcriptomic profile of yak oocytes

Zygote ◽  
2020 ◽  
Vol 28 (6) ◽  
pp. 459-469
Author(s):  
Ruizhe Li ◽  
Yuzhu Luo ◽  
Jingtao Xu ◽  
Yonggang Sun ◽  
Zhijie Ma ◽  
...  
Keyword(s):  
Oxygen Concentration ◽  
Enrichment Analysis ◽  
Oocyte Quality ◽  
Signalling Pathway ◽  
Developmental Competence ◽  
Low Oxygen ◽  
Transcriptomic Profile ◽  
Low Oxygen Concentration ◽  
Oxygen Concentrations

SummaryOxygen concentration influences oocyte quality and subsequent embryo development, but it remains unclear whether oxygen concentrations affect the developmental competence and transcriptomic profile of yak oocytes. In this study, we investigated the effects of different oxygen concentrations (5% versus 20%) on the developmental competence, reactive oxygen species (ROS) levels, glutathione (GSH) content, and transcriptomic profile of yak oocytes. The results showed that a low oxygen concentration significantly increased the maturation rate of yak oocytes (81.2 ± 2.2% vs 75.9 ± 1.3%) and the blastocyst quality of yak in vitro fertilized embryos. Analysis of ROS and GSH showed that a low oxygen concentration reduced ROS levels and increased the content of GSH (75.05 ± 7.1 ng/oocyte vs 50.63 ± 5.6 ng/oocyte). Furthermore, transcriptomic analysis identified 120 differentially expressed genes (DEGs) between the two groups of oocytes. Gene enrichment analysis of the DEGs indicated multiple cellular processes, including oxidative phosphorylation, transcription regulation, mitochondrial regulation, oestrogen signalling pathway, HIF-1 signalling pathway, TNF signalling pathway, were involved in the response to oxygen concentration alterations. Taken together, these results indicated that a low oxygen concentration improved the developmental competence of yak oocytes.

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