SNAIL and SLUG are zinc-finger transcription factors that participate in the regulation of cell division, cell survival, mesoderm formation and epithelial-to-mesenchymal transition. We investigate the expression of SNAIL and SLUG during follicular maturation, ovulation and luteinization in the ovaries of both neonatal mice and gonadotropin-induced immature mice. Furthermore, we examine the expression and localization of these transcription factors during early embryonic cleavage. Our data demonstrate that both SNAIL and SLUG are present in the epithelial cells of the ovarian surface in immature mice. SNAIL is first evident in the interstitial cells and theca cells by postnatal day (PD) 6 and then appears in the oocytes by PD 8, remaining at a constant expression level for all stages studied thereafter. SLUG is expressed in oocytes as early as PD 1. Its expression also increases with the development of the follicles in theca and interstitial cells but not in granulosa cells. In gonadotropin-induced immature mice, both SNAIL and SLUG are expressed in the corpora lutea. During early embryo cleavage, SNAIL occurs in the nucleus and cytoplasm of the majority of the embryo, excluding the nucleolus from the germinal vesicle breakdown (GVBD) to the 8-cell stage and is then localized in the cytoplasm during the morula stage and in the nucleus during the blastocyst stage. SLUG has an identical expression pattern as SNAIL from GVBD until the morula stage, except that it is localized in the cytoplasm during the blastocyst stage. Taken together, these different localization patterns suggest that SNAIL and SLUG probably play important roles during follicular development, luteinization and early embryonic development.
Polychlorinated biphenyls (PCBs) are stable, lipophilic compounds that accumulate in the environment and in the food chain. Though some studies provided evidence that PCBs had adverse effects on reproductive function, most of these results were from in vitro models. Therefore we investigated the effect of Aroclor 1254 (a commercial PCBs mixture) treatments on in vivo maturation and developmental potential of mouse oocytes. In the present study, female ICR mice were treated with different doses (12.5, 25 and 50 mg/kg) of Aroclor 1254 (a commercial PCB mixture) once every 72 hours by intraperitoneal injection for 9 days. After three treatments of Aroclor 1254, the mice were superovulated to collect oocytes one day after the last exposure. The effects of Aroclor 1254 on oocyte maturation, fertilization, and preimplantation embryonic development were investigated. Immunofluorescence-stained oocytes were observed under a confocal microscope to assess the effects of Aroclor 1254 on spindle morphology. Parthenogenic activation and the incidence of cumulus apoptosis in cumulus-oocyte complexes were observed as well. Oocytes exposed to different doses of Aroclor 1254 in vivo were associated with a significant decrease in outgrowth potential, abnormal spindle configurations, and the inhibition of parthenogenetic activation of ovulated oocytes. Furthermore, the incidence of apoptosis in cumulus cells was increased after exposed to Aroclor 1254. These results may provide reference for the treatment of reproductive diseases such as infertility or miscarriage caused by environmental contaminants.
The Apolipoprotein (Apo) family is implicated in lipid metabolism. There are five types of Apo: Apoa, Apob, Apoc, Apod, and Apoe. Apoe has been demonstrated to play a central role in lipoprotein metabolism and to be essential for efficient receptor-mediated plasma clearance of chylomicron remnants and VLDL remnant particles by the liver. Apoe-deficient (Apoe(-/-)) mice develop atherosclerotic plaques spontaneously, followed by obesity. In this study, we investigated whether lipid deposition caused by Apoe knockout affects reproduction in female mice. The results demonstrated that Apoe(-/-) mice were severely hypercholesterolemic, with their cholesterol metabolism disordered, and lipid accumulating in the ovaries causing the ovaries to be heavier compared with the WT counterparts. In addition, estrogen and progesterone decreased significantly at D 100. Quantitative PCR analysis demonstrated that at D 100 the expression of cytochromeP450 aromatase (Cyp19a1), 3?-hydroxysteroid dehydrogenase (Hsd3b), mechanistic target of rapamycin (Mtor), and nuclear factor-?B (Nfkb) decreased significantly, while that of BCL2-associated agonist of cell death (Bad) and tuberous sclerosis complex 2 (Tsc2) increased significantly in the Apoe(-/-) mice. However, there was no difference in the fertility rates of the Apoe(-/-) and WT mice; that is, obesity induced by Apoe knockout has no significant effect on reproduction. However, the deletion of Apoe increased the number of ovarian follicles and the ratio of ovarian follicle atresia and apoptosis. We believe that this work will augment our understanding of the role of Apoe in reproduction.
Three-dimensional (3D) graphene-based composite materials have attracted increasing attention, owing to their specific surface area, high conductivity and electronic interactions. Here, we report a convenient route to fabricate a 3D Co3O4/Graphene Hydrogel (CGH) composite as an electrode material for supercapacitors. Utilizing the gelation of a graphene oxide dispersion enables the anchoring of Co3O4 nanoparticles on the graphene sheet surfaces and formation of the hydrogel simultaneously. Remarkably, the spherical Co3O4 particles can serve as spacers to keep the neighboring graphene sheets separated. The CGH exhibits a high specific capacitance (Cs) of 757.5 F g(-1) at a current density of 0.5 A g(-1), indicating its potential application as an electrode material for supercapacitors.
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