Lipid and antioxidant supplements improve cryotolerance and embryonic quality of Metaphase II mouse oocytes undergoing vitrification

Author(s):  
Iara Viana ◽  
Paula Andrea Navarro
2020 ◽  
Vol 53 (6) ◽  
Author(s):  
Na‐Na Zhang ◽  
Teng Zhang ◽  
Wen‐Yi Gao ◽  
Xin Wang ◽  
Zi‐Bin Wang ◽  
...  
Keyword(s):  

Author(s):  
Meng-Hao Pan ◽  
Yu-Ke Wu ◽  
Bi-Yun Liao ◽  
Hui Zhang ◽  
Chan Li ◽  
...  

Bisphenol A (BPA) is one of the ubiquitous environmental endocrine disruptors (EEDs). Previous studies have shown that the reproduction toxicity of BPA could cause severe effects on the mammal oocytes and disturb the quality of mature oocytes. However, the toxic effects of BPA on the organelles of mouse oocytes have not been reported. In this study, to investigate whether BPA can be toxic to the organelles, we used different concentrations of BPA (50, 100, and 200 μM) to culture mouse oocytes in vitro. The results showed that 100 μM BPA exposure could significantly decrease the developmental capacity of oocytes. Then, we used the immunofluorescence staining, confocal microscopy, and western blotting to investigate the toxic effects of BPA on the organelles. The results revealed that mitochondrial dysfunction is manifested by abnormal distribution and decreased mitochondrial membrane potential. Moreover, the endoplasmic reticulum (ER) is abnormally distributed which is accompanied by ER stress showing increased expression of GRP78. For the Golgi apparatus, BPA-exposed dose not disorder the Golgi apparatus distribution but caused abnormal structure of Golgi apparatus, which is manifested by the decrease of GM130 protein expression. Moreover, we also found that BPA-exposed led to the damage of lysosome, which were shown by the increase of LAMP2 protein expression. Collectively, our findings demonstrated that the exposure of BPA could damage the normal function of the organelles, which may explain the reduced maturation quality of oocytes.


PLoS ONE ◽  
2014 ◽  
Vol 9 (6) ◽  
pp. e99393 ◽  
Author(s):  
Yihui Zhang ◽  
Li Shao ◽  
Yixin Xu ◽  
Yigui Cui ◽  
Jiayin Liu ◽  
...  
Keyword(s):  

2006 ◽  
Vol 18 (6) ◽  
pp. 697 ◽  
Author(s):  
Adil Salim Elsheikh ◽  
Yoshiyuki Takahashi ◽  
Seiji Katagiri ◽  
Hiroshi Kanagawa

This study was carried out to test the ability of sucrose-exposed chemically enucleated mouse oocytes to support the development of reconstituted embryos in vitro. Cumulus-enclosed germinal-vesicle-stage mouse oocytes were matured in vitro to metaphase I stage and were chemically enucleated with 50 µg mL–1 etoposide in tissue culture medium 199. The chemically enucleated oocytes were grouped into two groups. Group I was exposed to 0.75 m sucrose and group II was not exposed to sucrose. The zonae pellucidae of the chemically enucleated oocytes were removed with acid Tyrode’s solution (pH 2.7). They were then aggregated into couplets with karyoplasts from pronuclear-stage embryos using phytohemagglutinin-P. The couplets were electrically fused to form reconstituted embryos. The reconstituted embryos were activated with 7% ethanol and cultured in vitro in simplex optimisation medium to test their developmental ability to the blastocyst stage. Some of the reconstituted embryos that developed to the blastocyst stage were used for chromosome counts to test their ploidy. The results of the present study showed that chemically enucleated oocytes exposed to sucrose supported the development of reconstituted embryos to the blastocyst stage (21.5%), whereas those not exposed to sucrose did not. The chromosome counts showed that the reconstituted embryos had normal ploidy (40 chromosomes). It is concluded that sucrose exposure improves the quality of chemically enucleated mouse oocytes. Thus they can be used as recipients for mouse embryo cloning and nucleocytoplasmic interaction studies.


Author(s):  
K. T. Tokuyasu

During the past investigations of immunoferritin localization of intracellular antigens in ultrathin frozen sections, we found that the degree of negative staining required to delineate u1trastructural details was often too dense for the recognition of ferritin particles. The quality of positive staining of ultrathin frozen sections, on the other hand, has generally been far inferior to that attainable in conventional plastic embedded sections, particularly in the definition of membranes. As we discussed before, a main cause of this difficulty seemed to be the vulnerability of frozen sections to the damaging effects of air-water surface tension at the time of drying of the sections.Indeed, we found that the quality of positive staining is greatly improved when positively stained frozen sections are protected against the effects of surface tension by embedding them in thin layers of mechanically stable materials at the time of drying (unpublished).


Author(s):  
L. D. Jackel

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.


Author(s):  
G. Lehmpfuhl

Introduction In electron microscopic investigations of crystalline specimens the direct observation of the electron diffraction pattern gives additional information about the specimen. The quality of this information depends on the quality of the crystals or the crystal area contributing to the diffraction pattern. By selected area diffraction in a conventional electron microscope, specimen areas as small as 1 µ in diameter can be investigated. It is well known that crystal areas of that size which must be thin enough (in the order of 1000 Å) for electron microscopic investigations are normally somewhat distorted by bending, or they are not homogeneous. Furthermore, the crystal surface is not well defined over such a large area. These are facts which cause reduction of information in the diffraction pattern. The intensity of a diffraction spot, for example, depends on the crystal thickness. If the thickness is not uniform over the investigated area, one observes an averaged intensity, so that the intensity distribution in the diffraction pattern cannot be used for an analysis unless additional information is available.


Author(s):  
K. Shibatomi ◽  
T. Yamanoto ◽  
H. Koike

In the observation of a thick specimen by means of a transmission electron microscope, the intensity of electrons passing through the objective lens aperture is greatly reduced. So that the image is almost invisible. In addition to this fact, it have been reported that a chromatic aberration causes the deterioration of the image contrast rather than that of the resolution. The scanning electron microscope is, however, capable of electrically amplifying the signal of the decreasing intensity, and also free from a chromatic aberration so that the deterioration of the image contrast due to the aberration can be prevented. The electrical improvement of the image quality can be carried out by using the fascionating features of the SEM, that is, the amplification of a weak in-put signal forming the image and the descriminating action of the heigh level signal of the background. This paper reports some of the experimental results about the thickness dependence of the observability and quality of the image in the case of the transmission SEM.


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