Short Communication: Successful vitrification of mouse oocytes using the cryotop method with moderate cryoprotectant concentrations

2011 ◽  
Vol 91 (3) ◽  
pp. 385-388
Author(s):  
Afrooz Habibi ◽  
Ahmad Hosseini ◽  
Naser Farrokhi ◽  
Fardin Amidi ◽  
Isabel Carvalhais ◽  
...  

Habibi, A., Hosseini, A., Farrokhi, N., Amidi, F., Carvalhais, I., Chaveiro, A. and Moreira da Silva, F. 2011. Short Communication: Successful vitrification of mouse oocytes using the cryotop method with moderate cryoprotectant concentrations. Can. J. Anim. Sci. 91: 385–388. The response of vitrified mouse MII oocytes in the presence of two concentrations of cryoprotectants [vit1 (15%: 7.5% dimethyl sulfoxide (DMSO)+7.5% ethylene glycol (EG) and vit2 (30%: 15% DMSO+15% EG)] was analyzed to investigate whether reducing cryoprotectant concentrations can affect oocyte survival after cryopreservation by the cryotop method. After thawing the survival, fertilization, cleavage and blastocyst rates were compared with unfrozen oocytes. It can be concluded that 15% cryoprotectant (7.5% DMSO+7.5% EG), instead of the commonly used 30% (15% DMSO+15% EG), could be helpful by moderating the probable toxic effects of vitrification solution in mouse oocyte during vitrification by cryotop.

2019 ◽  
Vol 31 (1) ◽  
pp. 145 ◽  
Author(s):  
S. Ledda ◽  
S. Pinna ◽  
S. Nieddu ◽  
D. Natan ◽  
A. Arav ◽  
...  

Vitrification is a method extensively used for preserving oocytes and embryos and is also gaining acceptance for preserving gonadal tissue. Cryopreservation of spermatogonial stem cells is an applicable method for young males seeking fertility preservation before starting a treatment or can be a tool for genetic preservation of rare or high-value animals. The aim of this work was to evaluate the cryopreservation of testicular tissue from young lambs by vitrification using a new device named E.Vit (FertileSafe, Ness Ziona, Israel) that permits all cryopreservation procedures to be performed in straw. The new device consists of a 0.3-mL straw (Cryo Bio System, IMV, L’Aigle, France) with a capsule containing 50-µm pores inserted at one end. Testicular tissue extracts were prepared from testes of slaughtered lambs (n=10, 40 days old), opened by sagittal sectioning with a microblade and collecting small pieces of testicular tissue (1mm3) from the middle part of the rete testis. Three pieces of gonadal tissue were inserted into each E.Vit device. Each straw was sequentially loaded vertically in two 1.5-mL microtubes, which contained the following solutions: first, the equilibrating solution (7.5% dimethyl sulfoxide+7.5% ethylene glycol+20% FCS in TCM-199) for 6min, followed by 90min in the vitrification solution (18% dimethyl sulfoxide+18% ethylene glycol+0.5M Trehalose+BSA in TCM-199). After exposure to the equilibrating solution and vitrification solution, the solutions were removed and the straws were directly loaded into LN2. The warming procedure consisted of placing the straws directly into 5-mL tubes containing 100, 50, and 25% warming solution (1M sucrose in TCM-199+20% FCS) at 38.6°C for 5min each before arrival into the holding medium. Samples were recovered from the straws incubated at 38.6°C in 5% CO2 in air in TCM 199+5% FCS and evaluated at 0 and 2h post-warming for viability using trypan blue staining. Expression of a panel of specific genes (SOD2, HSP90b, BAX, POUF5/OCT4, TERT, CIRBP, KIF11, AR, FSHR) was analysed by real-time PCR in cryopreserved tissue in vitro cultured for 2h post-warming (2hV), in fresh controls immediately after tissue dissection (0hF), and after 2h of in vitro culture (2hF). The majority of cells survived after vitrification, although viability immediately after warming (0hV: 56%±1.45) or after 2h of in vitro culture (IVC) (2hV: 54±7%) was significantly lower compared with non-cryopreserved fresh controls (0hF: 89%±1.45; ANOVA P<0.05). Expression analysis showed specific patterns for the different genes. Notably, BAX transcript abundance was not affected by vitrification or IVC, indicating an acceptable level of stress for the cells. The genes HSP90b and CIRBP were down-regulated in 2hF but increased in 2hV, as expected. Expression of SOD1 and OCT4 was altered by vitrification but not by IVC. Conversely, expression of TERT, KIF11, and AR was affected by both IVC and cryopreservation (ANOVA P<0.05). This novel protocol for testicular tissue cryopreservation of prepubertal animals may be a promising strategy for fertility preservation and can contribute as a new approach in the development of large-scale biodiversity programs.


2015 ◽  
Vol 27 (1) ◽  
pp. 115
Author(s):  
S. Kondo ◽  
K. Imai ◽  
O. Dochi

The aim of this study was to test sucrose concentrations for single-step dilution on the viability of vitrified in vitro-produced bovine embryos. Blastocysts (n = 173, 7 to 8 days after fertilization) were vitrified using the Cryotop (Kitazato, Tokyo, Japan) method placement by incubating the blastocysts in Dulbecco's phosphate buffered saline supplemented with 20% calf serum, 7.5% ethylene glycol, and 7.5% dimethyl sulfoxide for 3 min and then transferring into vitrification solution (Dulbecco's phosphate buffered saline supplemented with 20% calf serum, 16.5% ethylene glycol, 16.5% dimethyl sulfoxide, and 0.5 M sucrose). Each embryo was placed on a Cryotop with minimum volume of vitrification solution, and then the Cryotop was plunged into liquid nitrogen. Total time from placement in vitrification solution to plunging into liquid nitrogen was 1 min. The blastocysts were warmed by incubation in the single-step dilution medium for 5 min [0 M sucrose (n = 42), 0.25 M sucrose (n = 44), 0.5 M sucrose (n = 43), and 1.0 M sucrose (n = 44)] at 38.0°C. After dilution, the embryos were washed in TCM-199 supplemented with 20% calf serum and 0.1 mM β-mercaptoethanol and were cultured for 72 h in the same medium at 38.5°C in an atmosphere of 5% CO2. The rates of re-expanded blastocysts and hatched blastocysts were determined at 24 and 72 h after warming, respectively. Data were analysed using the chi-squared test. The percent of re-expanded blastocysts at 24 h after warming in dilution medium supplemented with any level of sucrose was significantly higher (P < 0.05) than in blastocysts warmed without sucrose (Table 1). The hatched blastocyst rate of embryos at 72 h after warming in dilution medium with 0.5 M sucrose was significant higher than that with no sucrose. There were no differences in hatched blastocyst rates between the sucrose concentrations supplemented to the dilution medium. These results suggest that embryos vitrified by the Cryotop method can be diluted in single-step dilution using 0.25, 0.5, or 1.0 M sucrose supplemented to the medium. Table 1.The effect of sucrose concentration for single-step dilution on the viability of Cryotop vitrified in vitro-produced bovine embryos


2020 ◽  
Vol 32 (2) ◽  
pp. 140
Author(s):  
I. Martínez-Rodero ◽  
T. García-Martínez ◽  
M. López-Béjar ◽  
T. Mogas

For the successful application of vitrification technology to field conditions, the procedures for the warming and transfer of the cryopreserved bovine embryos should be as simple as possible. The device VitTrans, designed by our group, enables warming/dilution of embryos and their transfer directly to recipient females in field conditions (Morato and Mogas 2014 Cryobiology 68, 288). VitTrans vitrification protocol consists of an incubation in equilibration solution during 12min followed by an exposure of 40s to vitrification solution. However, there are other reports using similar vitrification devices where equilibration length is shorter than ours. This study aimed to improve VitTrans methodology by comparing two vitrification protocols: short equilibration (SE) and long equilibration (LE). A total of 63 invitro-produced Day 7 blastocysts (IETS stage code 7) were randomly placed in an equilibration solution with 7.5% ethylene glycol + 7.5% dimethyl sulfoxide in holding medium (tissue culture medium-199 HEPES + 20% fetal calf serum) for either 3min (SE) or 12min (LE). Then, blastocysts were transferred to vitrification solution (15% ethylene glycol + 15% dimethyl sulfoxide + 0.5M sucrose in holding medium) for 40s, loaded onto the VitTrans device, plunged into liquid nitrogen, and covered with a 0.5mL straw. Fresh nonvitrified blastocysts (n=30) were set as control. For warming, the VitTrans was quickly submerged into a water bath at 45°C, while a syringe containing 0.3mL of diluting solution (0.5M sucrose in holding medium) at 45°C was injected through the hollow of the device. Blastocysts were then transferred to synthetic oviductal fluid medium and cultured for 24h at 38.5% in a 5% CO2 and 5% O2 environment in a humidified atmosphere. Re-expansion rates were recorded 3 and 24h after warming. Blastocysts were fixed and stained with SOX2 (Invitrogen) for inner cell mass (ICM) count, TUNEL (Roche) for apoptosis index assessment, and DAPI (Vector Laboratories) for total cell count (TCC). Images were captured using a Leica TCS SP5 confocal microscope (Leica Microsystems) and examined with Imaris 9.2 software (Oxford Instruments). Blastocyst survival rates were compared between groups using chi-squared test. Blastocyst TCC, ICM count, and apoptosis indices were analysed using analysis of variance. Significance was set at P ≤ 0.05. No differences were observed in re-expansion rate at 3h postwarming (61.3 and 59.4% for SE and LE, respectively). However, significantly higher re-expansion rates were found after 24h of culture for the blastocysts of the SE group (74.2%) when compared with the blastocysts of the LE group (65.7%). Blastocysts vitrified using the LE protocol produced the lowest TCC (115±5.9; P ≤ 0.05), whereas TCC of the SE (152±9.7) and fresh control (138±8.6) treatments were similar. No differences were found in ICM count among groups. Nevertheless, apoptosis index was higher (P ≤ 0.05) in both vitrification groups when compared with fresh control. These results indicate that short equilibration vitrification not only improves VitTrans outcomes but adds efficiency by taking less time to perform. Supported by MCIU, Spain (Project AGL2016-79802-P and Grant BES-2017-081962).


PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5111 ◽  
Author(s):  
Yujie Lu ◽  
Yue Zhang ◽  
Jia-Qian Liu ◽  
Peng Zou ◽  
Lu Jia ◽  
...  

Background Aflatoxin B1 (AFB1), deoxynivalenol (DON), HT-2, ochratoxin A (OTA), zearalenone (ZEA) are the most common mycotoxins that are found in corn-based animal feed which have multiple toxic effects on animals and humans. Previous studies reported that these mycotoxins impaired mammalian oocyte quality. However, the effective concentrations of mycotoxins to animal oocytes were different. Methods In this study we aimed to compare the sensitivity of mouse and porcine oocytes to AFB1, DON, HT-2, OTA, and ZEA for mycotoxin research. We adopted the polar body extrusion rate of mouse and porcine oocyte as the standard for the effects of mycotoxins on oocyte maturation. Results and Discussion Our results showed that 10 μM AFB1 and 1 μM DON significantly affected porcine oocyte maturation compared with 50 μM AFB1 and 2 μM DON on mouse oocytes. However, 10 nM HT-2 significantly affected mouse oocyte maturation compared with 50 nM HT-2 on porcine oocytes. Moreover, 5 μM OTA and 10 μM ZEA significantly affected porcine oocyte maturation compared with 300 μM OTA and 50 μM ZEA on mouse oocytes. In summary, our results showed that porcine oocytes were more sensitive to AFB1, DON, OTA, and ZEA than mouse oocytes except HT-2 toxin.


2016 ◽  
Vol 28 (2) ◽  
pp. 151
Author(s):  
H. S. Canesin ◽  
I. Ortiz ◽  
J. G. Brom-de-Luna ◽  
Y. H. Choi ◽  
K. Hinrichs

Oocyte cryopreservation has the potential to preserve female genetics. In addition, equine oocytes are not readily available in some areas, and vitrification could be used to accumulate oocytes at remote locations to provide material for research. To preserve large numbers of oocytes, a method for rapid vitrification of multiple oocytes is needed. First, we determined whether immature equine oocytes could be held overnight before vitrification, and we tested the use of a mesh+capillary-action media-removal vitrification platform. Oocytes were collected via ultrasound-guided transvaginal follicle aspiration and randomly allotted to either immediate vitrification or overnight holding (24 to 27 h in 40% M199-Earle’s salts, 40% M199-Hanks’ salts, 20% fetal bovine serum, and 0.3 mM pyruvate) then vitrification. Oocytes were vitrified using different times (1 or 4 min) in vitrification solution and first warming solution: 1v1w, 1v4w, 4v1w, and 4v4w. The base solution was MH (80% M199-Hanks’ salts and 20% fetal bovine serum). Cryoprotectant concentration (vol/vol) was increased in 3 steps until reaching 7.5% dimethyl sulfoxide and 7.5% ethylene glycol. The oocytes were then held in vitrification solution (MH with 15% dimethyl sulfoxide, 15% ethylene glycol, and 0.5 M sucrose) for either 1 or 4 min, according to treatment, and 3 to 10 oocytes were transferred to a 75-μm sterile stainless steel mesh. The mesh was placed on sterile paper to absorb excess medium, then plunged in LN. The oocytes were warmed in MH solution with 1.25 M sucrose for either 1 or 4 min, then placed in 0.62 M and 0.31 M sucrose solutions for 5 min each and undetermined time in MH. After warming, oocytes were cultured for maturation (in vitro maturation) in M199-Earle’s salts, 5 mU mL–1 FSH, and 10% fetal bovine serum. After 30 to 36 h, the oocytes were denuded and stained with Hoechst 33258. Data were analysed by Fisher’s exact test. There were no significant differences (P > 0.05) in rates of meiotic resumption among timing treatments (35, 24, 26, and 39% for 1v1w, 1v4w, 4v1w, and 4v4w, respectively), nor between immediately vitrified (17/55, 31%) and overnight held-vitrified groups (18/56, 32%). In the second experiment, all oocytes were held overnight. They were vitrified and warmed using only the 1v1w and 4v4w schedules, then subjected to in vitro maturation, intracytoplasmic sperm injection, and embryo culture. The MII rate of the control group (27/37, 73%) was higher (P < 0.05) than that for 1v1w (12/33, 36%) or 4v4w treatments (10/35, 29%). The cleavage rate for control (25/27, 93%) was higher than that for 1v1w (5/9, 56%) but not than that for 4v4w (6/9, 67%). Blastocyst rates were 19% (5/27), 11% (1/9), and 0% (0/9) for control, 1v1w, and 4v4w, respectively (P > 0.05). These results indicate that blastocysts may be produced from equine immature oocytes vitrified en masse; however, both the maturation and blastocyst production rates were relatively low. Additional studies are required to improve the efficiency of this technique. This work was supported by the Clinical Equine ICSI Program, Texas A&M University.


2004 ◽  
Vol 68 (2) ◽  
pp. 250-258 ◽  
Author(s):  
Toshifumi Takahashi ◽  
Hideki Igarashi ◽  
Masakazu Doshida ◽  
Kazuhiro Takahashi ◽  
Kenji Nakahara ◽  
...  

2014 ◽  
Vol 14 (1) ◽  
pp. 28 ◽  
Author(s):  
Dongjie Zhou ◽  
Xinghui Shen ◽  
Yanli Gu ◽  
Na Zhang ◽  
Tong Li ◽  
...  

Cell Division ◽  
2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Ming-Hong Sun ◽  
Lin-Lin Hu ◽  
Chao-Ying Zhao ◽  
Xiang Lu ◽  
Yan-Ping Ren ◽  
...  

Abstract Background Ral family is a member of Ras-like GTPase superfamily, which includes RalA and RalB. RalA/B play important roles in many cell biological functions, including cytoskeleton dynamics, cell division, membrane transport, gene expression and signal transduction. However, whether RalA/B involve into the mammalian oocyte meiosis is still unclear. This study aimed to explore the roles of RalA/B during mouse oocyte maturation. Results Our results showed that RalA/B expressed at all stages of oocyte maturation, and they were enriched at the spindle periphery area after meiosis resumption. The injection of RalA/B siRNAs into the oocytes significantly disturbed the polar body extrusion, indicating the essential roles of RalA/B for oocyte maturation. We observed that in the RalA/B knockdown oocytes the actin filament fluorescence intensity was significantly increased at the both cortex and cytoplasm, and the chromosomes were failed to locate near the cortex, indicating that RalA/B regulate actin dynamics for spindle migration in mouse oocytes. Moreover, we also found that the Golgi apparatus distribution at the spindle periphery was disturbed after RalA/B depletion. Conclusions In summary, our results indicated that RalA/B affect actin dynamics for chromosome positioning and Golgi apparatus distribution in mouse oocytes.


1968 ◽  
Vol 12 (2) ◽  
pp. 156-178 ◽  
Author(s):  
Pete E. Benville ◽  
Charlie E. Smith ◽  
Warren E. Shanks

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