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Two-cell Embryos (two-cell + embryo)
Selected AbstractsCorrelation of the Mitochondrial Activity of Two-Cell Embryos Produced In Vitro and the Two-Cell Block In Kunming and B6C3F1 MiceTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 5 2009Shie Wang Abstract The correlation between the early embryonic block to development and mitochondrial activity was investigated comparing two-cell embryos produced in vitro from Kunming (KM) and B6C3F1 mice. One-cell embryos were obtained from two species of hybrids (female KM mice mated with KM males and female B6C3F1 mice mated with KM males) and cultured for 84 hr in M16 media. The mitochondrial membrane potential, ATP content, and reactive oxygen species levels were measured in the resulting KM and B6C3F1 two-cell embryos. Mitochondrial membrane potential and ATP content were also determined in KM and B6C3F1 metaphase II eggs. The results showed that the two-cell block was observed in cultured KM embryos but not in B6C3F1 embryos. Mitochondrial membrane potential and ATP content of KM two-cell embryos were significantly lower than in B6C3F1 two-cell embryos (P < 0.01). Interestingly, the reactive oxygen species levels of KM two-cell embryos were significantly lower than their B6C3F1 counterparts (P < 0.01). There was no difference in mitochondrial membrane potential and ATP content between KM and B6C3F1 metaphase II eggs. It is concluded that KM mice have an early two-cell embryo block and that a possible "blocking" mechanism is the lower mitochondrial membrane potential and ATP content in these embryos. The results suggest a new approach for overcoming early embryonic development block, that of manipulating mitochondrial activity. Anat Rec, 292:661,669, 2009. © 2009 Wiley-Liss, Inc. [source] The effect of paternal heat stress on protein profiles of pre-implantation embryos in the mouseINTERNATIONAL JOURNAL OF ANDROLOGY, Issue 3 2005B. ZHU Summary The study was undertaken to compare the protein profiles of [35S]-methionine-labelled control-sired embryos with heat-sired embryos at 7, 14 or 21 days after mature fertile B6CBF F1 male mice were kept at 36 ± 0.3 °C and 62 ± 2.7% relative humidity for 24 h. One-dimensional gel electrophoresis and autoradiographs were used to examine the protein profiles between the two-cell embryos and the blastocysts. The results obtained demonstrate that paternal heat stress 7 or 14 days earlier did not apparently affect protein patterns of two-cell embryos, four-cell to eight-cell embryos, morulae or blastocysts. However, 21 days earlier, there were changes in protein patterns of two-cell embryos and abnormal embryos, but not the morulae. To further support and extend these results, two-dimensional gel electrophoresis and phosphorimaging were employed and the results obtained show that paternal heat stress 21 days before mating affected protein profiles of two-cell embryos and morulae in the mouse. Together, these findings have indicated that paternal heat stress affects most but not all protein patterns of pre-implantation embryos, which strongly supports our previous results demonstrating that paternal heat stress significantly reduced the developmental proportion of pre-implantation embryos in the mouse. [source] Use of picosecond infrared laser for micromanipulation of early mammalian embryosMOLECULAR REPRODUCTION & DEVELOPMENT, Issue 10 2009Artashes V. Karmenyan A high repetition rate (80 MHz) picosecond pulse (,2 psec) infrared laser was used for the inactivation (functional enucleation) of oocytes and two-cell mouse embryos and also for the fusion of blastomeres of two-cell mouse embryos. The laser inactivation of both blastomeres of two-cell mouse embryos by irradiation of nucleoli completely blocked further development of the embryo. The inactivation of one blastomere, however, did not affect the ability of the second intact blastomere to develop into a blastocyst after treatment. Laser inactivation of oocytes at Metaphase II (MII) stage and parthenogenetically activated pronuclear oocytes also completely blocked their ability for further development. Suitable doses of irradiation in cytoplasm region did not affect the ability of embryos and activated oocytes to development. The efficiency of laser induced fusion for blastomeres of two-cell embryos was 66.7% and all the tetraploid embryos developed successfully into blastocysts in culture. Our results demonstrate unique opportunities of the applications of a suitable infrared periodic pulse laser as a universal microsurgery tool for individual living cells. Mol. Reprod. Dev. 76: 975,983, 2009. © 2009 Wiley-Liss, Inc. [source] Sperm defects in mice lacking a functional Niemann,Pick C1 protein,MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 10 2006Jun Fan Abstract The Niemann,Pick C1 (NPC1) gene encodes for a multiple membrane spanning protein, which regulates the trafficking of low-density lipoprotein-mediated endocytosed cholesterol. Mutation of the human NPC1 gene causes Niemann,Pick type C (NPC) disease. The Npc1NIH mice, a model of human NPC disease, bear a spontaneous mutation of the Npc1 gene, and are infertile. In this study, we have performed sperm analysis to search for the cause of male infertility in the Npc1NIH mouse. The number of cauda sperms in Npc1,/, mice was decreased roughly three-and-half-fold of that in wild-type mice. The decreased sperm number in Npc1,/, mice is due, at least in part, to partial arrest of spermatogenesis in the testes, as revealed by histological analysis. Compared to wild-type sperm, Npc1,/, sperm displayed a high frequency of morphological abnormalities, including tailless heads and aberrant heads. In the in vitro fertilization (IVF) assay using cumulus-intact eggs, Npc1,/, sperm failed to produce two-cell embryos. In the IVF assay where zona-free eggs were used, Npc1,/, sperm bound normally but could not fuse with the egg. Further analysis indicated that Npc1,/, sperms are drastically impaired in the binding to the egg zona pellucida, only 14% of the level of wild-type sperm. Moreover, on Npc1,/, cauda sperm, one-third of the total cyritestin protein was not proteolytically processed, while fertilin , was processed normally. Taken together, these results demonstrate that there are multiple defects in sperms from mice lacking a functional NPC1 protein, and these observed sperm defects may result in sterility. Mol. Reprod. Dev. © 2006 Wiley-Liss, Inc. [source] Correlation of the Mitochondrial Activity of Two-Cell Embryos Produced In Vitro and the Two-Cell Block In Kunming and B6C3F1 MiceTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 5 2009Shie Wang Abstract The correlation between the early embryonic block to development and mitochondrial activity was investigated comparing two-cell embryos produced in vitro from Kunming (KM) and B6C3F1 mice. One-cell embryos were obtained from two species of hybrids (female KM mice mated with KM males and female B6C3F1 mice mated with KM males) and cultured for 84 hr in M16 media. The mitochondrial membrane potential, ATP content, and reactive oxygen species levels were measured in the resulting KM and B6C3F1 two-cell embryos. Mitochondrial membrane potential and ATP content were also determined in KM and B6C3F1 metaphase II eggs. The results showed that the two-cell block was observed in cultured KM embryos but not in B6C3F1 embryos. Mitochondrial membrane potential and ATP content of KM two-cell embryos were significantly lower than in B6C3F1 two-cell embryos (P < 0.01). Interestingly, the reactive oxygen species levels of KM two-cell embryos were significantly lower than their B6C3F1 counterparts (P < 0.01). There was no difference in mitochondrial membrane potential and ATP content between KM and B6C3F1 metaphase II eggs. It is concluded that KM mice have an early two-cell embryo block and that a possible "blocking" mechanism is the lower mitochondrial membrane potential and ATP content in these embryos. The results suggest a new approach for overcoming early embryonic development block, that of manipulating mitochondrial activity. Anat Rec, 292:661,669, 2009. © 2009 Wiley-Liss, Inc. [source] Curcumin disrupts meiotic and mitotic divisions via spindle impairment and inhibition of CDK1 activityCELL PROLIFERATION, Issue 4 2010A. Bielak-Zmijewska Objectives:, Curcumin, a natural compound, is a potent anti-cancer agent, which inhibits cell division and/or induces cell death. It is believed that normal cells are less sensitive to curcumin than malignant cells; however, the mechanism(s) responsible for curcumin's effect on normal cells are poorly understood. The aim of this study was to verify the hypothesis that curcumin affects normal cell division by influencing microtubule stability, using mouse oocyte and early embryo model systems. Materials and methods:, Maturating mouse oocytes and two-cell embryos were treated with different concentrations of curcumin (10,50 ,m), and meiotic resumption and mitotic cleavage were analysed. Spindle and chromatin structure were visualized using confocal microscopy. In addition, acetylation and in vitro polymerization of tubulin, in the presence of curcumin, were investigated and the damage to double-stranded DNA was studied using ,H2A.X. CDK1 activity was measured. Results and conclusions:, We have shown for the first time, that curcumin, in a dose-dependent manner, delays and partially inhibits meiotic resumption of oocytes and inhibits meiotic and mitotic divisions by causing disruption of spindle structure and does not induce DNA damage. Our analysis indicated that curcumin affects CDK1 kinase activity but does not directly affect microtubule polymerization and tubulin acetylation. As our study showed that curcumin impairs generative and somatic cell division, its future clinical use or of its derivatives with improved bioavailability after oral administration, should take into consideration the possibility of extensive side-effects on normal cells. [source] | ||||||||||