Mice preantral follicles were cultured in vitro for 12 days to achieve metaphase Ⅱ (M Ⅱ ) oocytes. Oocyte growth differentiation factor-9 (GDF-9) gene expression was measured during different growth stages to ex...Mice preantral follicles were cultured in vitro for 12 days to achieve metaphase Ⅱ (M Ⅱ ) oocytes. Oocyte growth differentiation factor-9 (GDF-9) gene expression was measured during different growth stages to explore the relationship between oocyte maturation and GDF-9 gene expression. Preantral follicles of lO-day old mice were isolated from the ovaries and were cultured for 12 days. Oocytes from day 2 (D2), D4, D6, D8, DIO, D12 cultured in vitro were named the in vitro group and oocytes of day 12 (D12), D14, D16, D18, D20, D22 grown in vivo were named the in vivo group. Follicle survival, antrum formation and maturation rate were 89.5%, 51.8% and 56.6% respectively in follicles cultured in vitro. After RT-PCR and agarose gel electrophoresis, relative mRNA abundance of GDF-9 was measured in each group of oocytes. At day 8 - 12, the GDF-9 gene expression level of oocytes in vitro was significantly lower than that in vivo (P 〈 0.05). We conclude that M Ⅱ oocytes can be obtained from in vitro culture of preantral follicles. The GDF- 9 gene expression of oocytes varies at different growth stages in vivo. The low expression of GDF-9 in oocytes cuhured in vitro may be the cause of their low developmental capacity.展开更多
We investigated the long-lasting effects of early postnatal tactile stimulation (TS) and maternal separation (MS) on the emotional behaviors of adult female rats. A split-litter design was introduced to remove con...We investigated the long-lasting effects of early postnatal tactile stimulation (TS) and maternal separation (MS) on the emotional behaviors of adult female rats. A split-litter design was introduced to remove confusing factors such as maternal disturbance. Pups of the non-tactile stimulation (NTS) group did not receive any handling. Pups subjected to the TS treatment were handled and marked for approximately 30 s daily from postnatal days (PND) 2 - 9 or from PND 10 - 17. Pups subjected to the MS treatment were handled and marked in the same way as the TS pups and then individually placed in a cup with familiar nest bedding for 1 h daily. At the age of 3 months, female rats with different neonatal experiences were employed in the light/dark box test and the one-trial passive avoidance response. Both PND 2 - 9 TS and PND 10 - 17 TS groups exhibited more time spent in the illuminated chamber of the light/dark box, and longer step-through latencies in the passive avoidance response when compared to the NTS group, indicating that early life TS treatment reduced novelty-induced anxious emotion and facilitated the retention of emotional memory in adult female rats. No significant effects were found on any behavioral measures between the MS groups and the TS groups, suggesting that neonatal short-time MS treatment was not intensive enough to alter the emotional behaviors, at least in female rats. Infantile age was not an effective factor for these measures. This result supports the hypothesis that neonatal tactile stimulation and maternal separation lead to different effects on the neural development of postnatal pups.展开更多
Comparisons of activation rates and fertilization rates were made among oocytes at different ages. Results showed that oocytes at different ages had different activation and fertilization rates when stimulated by sper...Comparisons of activation rates and fertilization rates were made among oocytes at different ages. Results showed that oocytes at different ages had different activation and fertilization rates when stimulated by sperm or ethanol. Oocytes at 15~24 h after the injection of hCG were readily activated by 8% ethanol. The activation rate of oocytes increased with the age of oocytes, up to the highest average of 81.6%, but decreased after 20 h posthCG. Oocytes at 20 h posthCG exhibited the highest immediate cleavage rate(48.0%) after being stimulated by ethanol. On the other hand, 13~15 h oocytes exhibited higher fertilization rates, and the older oocytes were more difficult to be fertilized by sperm in vitro. These suggest that oocytes can be activated in different ways; the mechanism of fertilization might be different from that of activation; and in vitro fertilization is more dependent on oocyte age.展开更多
The chronological and morphological changes of the nucleus during mouse oocyte maturation and fertilization were systematically studied. Although most oocytes went through GVBD 2-4 hrs after culture, 13.6% remained at...The chronological and morphological changes of the nucleus during mouse oocyte maturation and fertilization were systematically studied. Although most oocytes went through GVBD 2-4 hrs after culture, 13.6% remained at GV stage 8 hrs after culture.TEM observation revealed that nucleoli of oocytes which failed to go through GVBD were composed of fibrillar-granular component,small vacuoles and fibrillar centers or showed small vacuoles on nuclear surface. During GVBD, the nucleoli became smaller and smaller and finally disappeared with the nuclear-associated chromatin dislocated to the periphery. Nuclear membrane with attached chromatin became folded and electronic dense cores appeared in the center of chromatin clumps at the same time.The last event of GVBD was the disruption of nuclear membrane.At the end of the 5th hr after culture, meiosis progressed to prometaphase I.Chromosomes,distributed in the original GV area free of organelles,were surrounded by large quantity of mitochondria and small SER vesicles. At the end of the 12th hr after culture,48. 1% of the oocytes emitted PB1.Decondensing sperm head and early male pronuclcus(mPN)with condensed nucleoli were found 1-2 hrs after insemination.The formation and enlargement of female PN(fPN) occurred a little earlier than that of mPN. 33.3% finished syngamy at 8-9 hrs after insemination.The process of nucleolus formation was reverse to that in GVBD. The oolemma modification caused by cortical reaction could effectively inhibit polyspermy.in contrast,there were sperm binding to the oolemma where CGs failed to be released. In addition, PB2 was emitted 2-5 hrs after insemination. The difference between PB1 and PB2 as well as the abstriction of polar body were also discussed.展开更多
Expression of the adhesion molecules, ICAM-1, VCAM-1, NCAM, CD44, CD49d (VLA-4, a chain), and CDlla (LFA-1, a chain) on mouse oocytes, and pre- and peri-implantation stage embryos was examined by quantitative indirect...Expression of the adhesion molecules, ICAM-1, VCAM-1, NCAM, CD44, CD49d (VLA-4, a chain), and CDlla (LFA-1, a chain) on mouse oocytes, and pre- and peri-implantation stage embryos was examined by quantitative indirect immunofluorescence microscopy. ICAM-1 was most strongly expressed at the oocyte stage, gradually declining almost to undetectable levels by the expanded blastocyst stage. NCAM, also expressed maximally on the oocyte, declined to undetectable levels beyond the morula stage. On the other hand, CD44 declined from highest expression at the oocyte stage to show a second maximum at the compacted 8-cell/morula. This molecule exhibited high expression around contact areas between trophecto-derm and zona pellucida during blastocyst hatching. CD49d was highly expressed in the oocyte, remained significantly expressed throughout and after blastocyst hatching was expressed on the polar trophecto-derm. Like CD44, CD49d declined to undetectable levels at the blastocyst outgrowth stage. Expression of both VCAM-1 and CDlla was undetectable throughout. The diametrical temporal expression pattern of ICAM-1 and NCAM compared to CD44 and CD49d suggest that dynamic changes in expression of adhesion molecules may be important for interaction of the embryo with the maternal cellular environment as well as for continuing development and survival of the early embryo.展开更多
Mature eggs (at metaphase Ⅱ stage) produce a series of Ca2+ oscillation at fertilization. To define whether the fertilization-induced Ca2+ oscillation is restrict to the metaphase Ⅱ eggs and cell cycle dependent, mo...Mature eggs (at metaphase Ⅱ stage) produce a series of Ca2+ oscillation at fertilization. To define whether the fertilization-induced Ca2+ oscillation is restrict to the metaphase Ⅱ eggs and cell cycle dependent, mouse oocytes at prophase Ⅰ (arrested at germinal vesicle stage),metaphase Ⅰ, metaphase Ⅱ, as well as the pronuclear embryos at interphase of the first mitotic division derived from fertilization or parthenogenetic activation were inseminated after removal of zona pellucida. The results show that the fertilization-induced Ca2+ oscillation is not specific to metaphase Ⅱ eggs. This is supported by the fact that immature oocytes generated the Ca2+ oscillations at fertilization regardless of their nuclear progression from prophase Ⅰ to metaphase Ⅰ (in vitro matured) stage. More interestingly, it was first found that pronuclear embryos at interphase derived from parthenogenetic activation showed Ca2+ oscillations in response to fertilization while the zygotes at interphase did not after reinsemination or intracytoplasmic injection of sperm extracts which induce Ca2+ oscillations in MII eggs. This suggests that the ability of oocytes to generate Ca2+ oscillation in response to sperm penetration is not regulated in a cell cycle dependent manner but dependent on the cytoplasmic maturation.展开更多
Mouse oocytes undergo polarization during meiotic maturation, and this polarization is essential for asymmetric cell divisions that maximize retention of maternal components required for early development. Without con...Mouse oocytes undergo polarization during meiotic maturation, and this polarization is essential for asymmetric cell divisions that maximize retention of maternal components required for early development. Without conventional centrosomes, the meiotic spindle has less focused poles and is barrel-shaped. The migration of meiotic spindles to the cortex is accompanied by a local reorganization and polarization of the cortex. LGN is a conserved protein involved in cell polarity and regulation of spindle organization. In the present study, we characterized the localization dynamics of LGN during mouse oocyte maturation and analyzed the effects of LGN upregulation and downregulation on meiotic spindle organization. At the germinal vesicle stage, LGN is distributed both cytoplasmically and at the cortex. During maturation, LGN localizes to the meiotic spindle apparatus and cortical LGN becomes less concentrated at the actin cap region. Excessive LGN induces meiotic spindle organization defects by elongating the spindle and enhancing pole focusing, whereas depletion of LGN by RNA interference results in meiotic spindle deformation and chromosome misalignment. Furthermore, the N-terminus of LGN has the ability of full-length LGN to regulate spindle organization, whereas the C-terminus of LGN controls cortical localization and polarization. Our results reveal that LGN is cortically polarized in mouse oocytes and is critical for meiotic spindle organization.展开更多
AIM: Hepatitis B is a worldwide public health problem. To explore the feasibility of hepatitis B virus (HBV) vertical transmission via oocytes, the presence and integration of HBV DNA in mouse oocytes were studied. ME...AIM: Hepatitis B is a worldwide public health problem. To explore the feasibility of hepatitis B virus (HBV) vertical transmission via oocytes, the presence and integration of HBV DNA in mouse oocytes were studied. METHODS: Genomic DNA was isolated and metaphases were prepared, respectively from mouse oocytes cocultured with pBR322-HBV DNA plasmids. PCR, Southern blot, dot hybridization and fluorescence in situ hybridization (FISH) were performed to explore the existence and integration of HBV DNA in oocytes.RESULTS: PCR detected positive bands in the tested samples, and then Southern blot revealed clear hybridization signals in PCR products. Final washing solutions were collected for dot hybridization and no signal for HBV DNA was observed, which excluded the possibility that contamination of washing solutions gave rise to positive results of PCR and Southern blot. FISH demonstrated that 36 of 1 000 metaphases presented positive signals. CONCLUSION: HBV DNA sequences are able to pass through the zona and oolemma to enter into oocytes and tointegrate into their chromosomes. HBV DNA sequences might be brought into embryo via oocytes as vectors when they are fertilized with normal spermatozoa.展开更多
Although the role of oxidative stress in maternal aging and infertility has been suggested, the underlying mechanisms are not fully understood. The present study is designed to determine the relationship between mitoc...Although the role of oxidative stress in maternal aging and infertility has been suggested, the underlying mechanisms are not fully understood. The present study is designed to determine the relationship between mitochondrial function and spindle stability in metaphase II (MII) oocytes under oxidative stress. MII mouse oocytes were treated with H2O2 in the presence or absence of permeability transition pores (PTPs) blockers cyclosporin A (CsA). In addition, antioxidant N-acetylcysteine (NAC), F0/F1 synthase inhibitor oligomycin A, the mitochondria uncoupler carbonyl cyanide 4-trifluoro- methoxyphenylhydrazone (FCCP) or thapsigargin plus 2.5 mM Ca^2+ (Th+2.5 mM Ca^2+) were used in mechanistic studies. Morphologic analyses of oocyte spindles and chromosomes were performed and mitochondrial membrane potential (AWm), cytoplasmic free calcium concentration ([Ca^2+]c) and cytoplasmic ATP content within oocytes were also assayed. In a time- and H202 dose-dependent manner, disruption of meiotic spindles was found after oocytes were treated with H202, which was prevented by pre-treatment with NAC. Administration of H2O2 led to a dissipation of AWm, an increase in [Ca^2+]c and a decrease in cytoplasmic ATP levels. These detrimental responses of oocytes to H2O2 treatment could be blocked by pre-incubation with CsA. Similar to H2O2, both oligomycin A and FCCP dissipated AWm, decreased cytoplasmic ATP contents and disassembled MII oocyte spindles, while high [Ca^2+]c alone had no effects on spindle morphology. In conclusion, the decrease in mitochondria-derived ATP during oxidative stress may cause a disassembly of mouse MII oocyte spindles, presumably due to the opening of the mitochondrial PTPs.展开更多
This research focused using novel substrate, longan Lactobacillus casei subsp, rhamnosus TISTR 108. The optimum juice as carbon source for continuous lactic acid production by medium for lactic acid production was pur...This research focused using novel substrate, longan Lactobacillus casei subsp, rhamnosus TISTR 108. The optimum juice as carbon source for continuous lactic acid production by medium for lactic acid production was pure longan juice with 120 g/L sugar concentration and among the different nitrogen sources were added to the longan juice (yeast extract, tryptic soy, urea, (NH4)2SO4 and NaNO3), yeast extract had the most efficiency. Yeast extract (10 g/L) without adding minerals to longan juice could produced the maximum lactic acid concentration of 38.91 ± 0.190 g/L in 60 h and the yield of 0.460± 0.122 g/g with the productivity of 0.649± 0.002 g/Lh in 2 liters flask. Batch fermentation was conducted in 2 liters fermentor and 41.38± 0.030 g/L lactic acid was produced in 48 h with the yield of 0.398 ± 0.215 g/g and the productivity was 0.862 ± 0.001 g/L h. The continuous fermentation using 2 liters fermentor as a high productivity for lactic acid (1.091 ± 0.001 g/L h) was achieved at dilution rate (D) of 0.0685 h-1.展开更多
AIM:To investigate the effects of Saccharomyces boulardii(S.boulardii) in an experimental rat model of trinitrobenzene sulfonic acid(TNBS)-induced colitis.METHODS:Thirty-two Wistar albino female rats were categorized ...AIM:To investigate the effects of Saccharomyces boulardii(S.boulardii) in an experimental rat model of trinitrobenzene sulfonic acid(TNBS)-induced colitis.METHODS:Thirty-two Wistar albino female rats were categorized into five groups.On the first day of the study,50 mg TNBS was administered via a rectal catheter in order to induce colitis in all rats,except those in the control group.For 14 d,the rats were fed a standard diet,without the administration of any additional supplements to either the control or TNBS groups,in addition to 1 mg/kg per day S.boulardii to the S.boulardii group,1 mg/kg per day methyl prednisolone(MP) to the MP group.The animals in the S.boulardii + MP group were coadministered these doses of S.boulardii and MP.During the study,weight loss,stool consistency,and the presence of obvious blood in the stool were evaluated,and the disease activity index(DAI) for colitis was recorded.The intestines were examined and colitis was macro-and microscopically scored.The serum and tissue levels of tumor necrosis factor-α(TNF-α) and nitric oxide(NO) were determined,and fungemia was evaluated in the blood samples.RESULTS:The mean DAI scores for the MP and S.boulardii + MP groups was significantly lower than the TNBS group(3.69 ± 0.61 vs 4.46 ± 0.34,P = 0.018 and 3.77 ± 0.73 vs 4.46 ± 0.34,P = 0.025,respectively).While no significant differences between the TNBS and the S.boulardii or MP groups could be determined in terms of serum NO levels,the level of serum NO in the S.boulardii + MP group was significantly higher than in the TNBS and S.boulardii groups(8.12 ± 4.25 μmol/L vs 3.18 ± 1.19 μmol/L,P = 0.013;8.12 ± 4.25 μmol/L vs 3.47 ± 1.66 μmol/L,P = 0.012,respectively).The tissue NO levels in the S.boulardii,MP and S.boulardii + MP groups were significantly lower than the TNBS group(16.62 ± 2.27 μmol/L vs 29.72 ± 6.10 μmol/L,P = 0.002;14.66 ± 5.18 μmol/Lvs 29.72 ± 6.10 μmol/L,P = 0.003;11.95 ± 2.34 μmol/Lvs 29.72 ± 6.10 μmol/L,P = 0.002,respectively).The tissue NO levels in the S.boulardii,MP and S.boulardii + MP groups were similar.The mean serum and tissue TNF-α levels were determined to be 12.97 ± 18.90 pg/mL and 21.75 ± 15.04 pg/mL in the control group,18.25 ± 15.44 pg/mL and 25.27 ± 11.95 pg/mL in the TNBS group,20.59 ± 16.15 pg/mL and 24.39 ± 13.06 pg/mL in the S.boulardii group,9.05 ± 5.13 pg/mL and 24.46 ± 10.85 pg/mL in the MP group,and 13.95 ± 10.17 pg/mL and 24.26 ± 10.37 pg/mL in the S.boulardii + MP group.Significant differences in terms of the levels of serum and tissue TNF-α and the macroscopic and microscopic scores were not found between the groups.S.boulardii fungemia was not observed in any of the rats.However,Candida fungemia was detected in one rat(14%) in the TNBS group,two rats(28%) in the S.boulardii group,three rats(50%) in the MP group,and three rats(42%) in S.boulardii + MP group.CONCLUSION:S.boulardii does not demonstrate considerable effects on the DAI,pathological scores,or cytokine levels but does decrease the tissue NO levels.展开更多
On Nov 17th,a team of researchers from the Shanghai Institute of Biochemistry and Cell Biology(SIBCB),Shanghai Institutes for Biological Sciences,CAS led by Prof.LI Jinsong reports online in Cell Research a novel te...On Nov 17th,a team of researchers from the Shanghai Institute of Biochemistry and Cell Biology(SIBCB),Shanghai Institutes for Biological Sciences,CAS led by Prof.LI Jinsong reports online in Cell Research a novel technique to induce from mice oocytes haploid embryonic stems cells(haESCs)that can fully replace the reproductive functions of sperms,greatly simplifying the otherwise complicated techniques to produce such stem cells and semi-cloned(SC)mice.It is anticipated that this will further facilitate research in the field of stem cells and embryonic development;展开更多
[Objective ] The study aimed to provide a theoretical basis for the clinical application of collagen peptide from Cyanea nozakii. [ Method] After acute toxicity test on mice, collagen peptide from C. nozakii were give...[Objective ] The study aimed to provide a theoretical basis for the clinical application of collagen peptide from Cyanea nozakii. [ Method] After acute toxicity test on mice, collagen peptide from C. nozakii were given to mice by continuous intragastric administration for 30 d at the doses of 25, 50, 100 mg/kg, and then the phagocytosis of macrophage, delayed type hypersensitivity (DTH) and serum hemolysin level were determined. [ Result] Collagen peptide from C. nozakii was atoxic or low toxic, and the three immune indices of experimental groups were signifi- canUy higher than those of the control group (treated with same volume of normal saline) at 0.05 or 0.01 level. E Conclusion] Collagen peptide from C. nozakii has a certain immunopotentiation.展开更多
Recombinant human-salmon calcxtonin (hsCT) was synthesized and expressea on the cell surtaces ot recombinant Saccharomyces cerevisiae (yAGA2-hsCT) using the pAGA2-hsCT expression vector. Expression of recombinant ...Recombinant human-salmon calcxtonin (hsCT) was synthesized and expressea on the cell surtaces ot recombinant Saccharomyces cerevisiae (yAGA2-hsCT) using the pAGA2-hsCT expression vector. Expression of recombinant hsCT was verified by flow cytometer.The resorption activity of osteoclasts was inhibited by recombinant hsCT protein which released from the cell surface of yAGA2-hsCT. Blood calcium determination in rats showed the activity of yAGA2-hsCT following oral administration of 5 mg/kg lyophilized transformant yeast to hypercalcemia rats decreases the serum calcium from 2.82 ±0.023 mM to 2.662 ± 0.012 mM.展开更多
The ingestion of probiotic lactic acid bacteria has been evaluated and noted that it has an effect on the balance of desirable microbiota in the gastrointestinal tract. Lactobacillus gasseri demonstrates good survival...The ingestion of probiotic lactic acid bacteria has been evaluated and noted that it has an effect on the balance of desirable microbiota in the gastrointestinal tract. Lactobacillus gasseri demonstrates good survival in the gastrointestinal tract, and it has been associated with a variety of probiotic activities and roles, including the reduction of fecal mutagenic enzymes, the production of bacteriocins and the stimulation of macrophages immunomodulation. The aim of the study was to evaluate the effects of a pool of L. gasseri strains isolated from the feces of breastfed infants added in the human milk of healthy women. The milk was both pasteurized and unpasteurized, to verify the cell cytotoxicity of macrophages and to quantify the production of immunologic mediators such as IL-4, IL-6, IFN-γ, TNF-α, NO and oxygen intermediary compounds (H2O2). The administration of raw human milk and pasteurized human milk to infants is a regular, encouraged practice in units of intensive therapy (UITs) and our present investigation verified the beneficial effect of addition of a pool of L. gasseri to pasteurized human milk (PHML). Our results show that probiotic supplementation helped to maintain cell viability, reduced IL-6 and IFN-γ production and stimulated TNF-α, NO, H2O2, IL-4 production. Nevertheless, the results indicate that the addition of lactobacillus to human milk was not a determinant in the production of TNF-α. L. gasseri added to breast milk did not present a cytotoxic risk, and the addition ofL. gasseri to pasteurized milk of human milk bank would benefit newborns that depend on milk banks for the colonization of more desirable microbiota.展开更多
The presence of Geotrichum candidum in fresh cheese is considered to be a contaminant and may lead to the product spoilage. The oxidative yeast Candida maltosa firstly isolated from the spoiled fruit yoghurt surface i...The presence of Geotrichum candidum in fresh cheese is considered to be a contaminant and may lead to the product spoilage. The oxidative yeast Candida maltosa firstly isolated from the spoiled fruit yoghurt surface in Slovakia belongs to the yeast contaminants of fermented dairy products. The effect of the cultivation temperature and the presence of Lactobacillus rhamnosus GG on the growth of dairy spoilage yeasts in ultrapasteurized milk was studied. Addition of Lb. rhamnosus GG in milk caused partial inhibition of the yeast growth dynamics in milk. The water activity transformation of Gibson model after the temperature modification (Tw) was applied to model growth dynamics of G. candidum in pure and mixed culture, respectively: In μ_Gc=-5.0376+2.7281 Tw-0.4217Tw^2, lnμ_CC_LGG=-6.0033+3.2996Tw-0.5553Tw^2. The effect of different Lb. rhamnosus GG addition and the incubation temperature on the C. maltosa growth dynamics was analyzed by linear regression methodology and described by using following equations: lnGr1=-5.3674+0.2341T+0.2599N0-0.0032T^2-0.0492N0^2-0.0068TN0 and lnGr11=-9.5457-0.249T+2.3823N0 +0.0099T^2-0.2324N0^2+0.0098TN0 Based on the principles of predictive microbiology, the mutual microbial interactions and potential application of the lactobacillus strains in food protection are discussed.展开更多
文摘Mice preantral follicles were cultured in vitro for 12 days to achieve metaphase Ⅱ (M Ⅱ ) oocytes. Oocyte growth differentiation factor-9 (GDF-9) gene expression was measured during different growth stages to explore the relationship between oocyte maturation and GDF-9 gene expression. Preantral follicles of lO-day old mice were isolated from the ovaries and were cultured for 12 days. Oocytes from day 2 (D2), D4, D6, D8, DIO, D12 cultured in vitro were named the in vitro group and oocytes of day 12 (D12), D14, D16, D18, D20, D22 grown in vivo were named the in vivo group. Follicle survival, antrum formation and maturation rate were 89.5%, 51.8% and 56.6% respectively in follicles cultured in vitro. After RT-PCR and agarose gel electrophoresis, relative mRNA abundance of GDF-9 was measured in each group of oocytes. At day 8 - 12, the GDF-9 gene expression level of oocytes in vitro was significantly lower than that in vivo (P 〈 0.05). We conclude that M Ⅱ oocytes can be obtained from in vitro culture of preantral follicles. The GDF- 9 gene expression of oocytes varies at different growth stages in vivo. The low expression of GDF-9 in oocytes cuhured in vitro may be the cause of their low developmental capacity.
文摘We investigated the long-lasting effects of early postnatal tactile stimulation (TS) and maternal separation (MS) on the emotional behaviors of adult female rats. A split-litter design was introduced to remove confusing factors such as maternal disturbance. Pups of the non-tactile stimulation (NTS) group did not receive any handling. Pups subjected to the TS treatment were handled and marked for approximately 30 s daily from postnatal days (PND) 2 - 9 or from PND 10 - 17. Pups subjected to the MS treatment were handled and marked in the same way as the TS pups and then individually placed in a cup with familiar nest bedding for 1 h daily. At the age of 3 months, female rats with different neonatal experiences were employed in the light/dark box test and the one-trial passive avoidance response. Both PND 2 - 9 TS and PND 10 - 17 TS groups exhibited more time spent in the illuminated chamber of the light/dark box, and longer step-through latencies in the passive avoidance response when compared to the NTS group, indicating that early life TS treatment reduced novelty-induced anxious emotion and facilitated the retention of emotional memory in adult female rats. No significant effects were found on any behavioral measures between the MS groups and the TS groups, suggesting that neonatal short-time MS treatment was not intensive enough to alter the emotional behaviors, at least in female rats. Infantile age was not an effective factor for these measures. This result supports the hypothesis that neonatal tactile stimulation and maternal separation lead to different effects on the neural development of postnatal pups.
文摘Comparisons of activation rates and fertilization rates were made among oocytes at different ages. Results showed that oocytes at different ages had different activation and fertilization rates when stimulated by sperm or ethanol. Oocytes at 15~24 h after the injection of hCG were readily activated by 8% ethanol. The activation rate of oocytes increased with the age of oocytes, up to the highest average of 81.6%, but decreased after 20 h posthCG. Oocytes at 20 h posthCG exhibited the highest immediate cleavage rate(48.0%) after being stimulated by ethanol. On the other hand, 13~15 h oocytes exhibited higher fertilization rates, and the older oocytes were more difficult to be fertilized by sperm in vitro. These suggest that oocytes can be activated in different ways; the mechanism of fertilization might be different from that of activation; and in vitro fertilization is more dependent on oocyte age.
文摘The chronological and morphological changes of the nucleus during mouse oocyte maturation and fertilization were systematically studied. Although most oocytes went through GVBD 2-4 hrs after culture, 13.6% remained at GV stage 8 hrs after culture.TEM observation revealed that nucleoli of oocytes which failed to go through GVBD were composed of fibrillar-granular component,small vacuoles and fibrillar centers or showed small vacuoles on nuclear surface. During GVBD, the nucleoli became smaller and smaller and finally disappeared with the nuclear-associated chromatin dislocated to the periphery. Nuclear membrane with attached chromatin became folded and electronic dense cores appeared in the center of chromatin clumps at the same time.The last event of GVBD was the disruption of nuclear membrane.At the end of the 5th hr after culture, meiosis progressed to prometaphase I.Chromosomes,distributed in the original GV area free of organelles,were surrounded by large quantity of mitochondria and small SER vesicles. At the end of the 12th hr after culture,48. 1% of the oocytes emitted PB1.Decondensing sperm head and early male pronuclcus(mPN)with condensed nucleoli were found 1-2 hrs after insemination.The formation and enlargement of female PN(fPN) occurred a little earlier than that of mPN. 33.3% finished syngamy at 8-9 hrs after insemination.The process of nucleolus formation was reverse to that in GVBD. The oolemma modification caused by cortical reaction could effectively inhibit polyspermy.in contrast,there were sperm binding to the oolemma where CGs failed to be released. In addition, PB2 was emitted 2-5 hrs after insemination. The difference between PB1 and PB2 as well as the abstriction of polar body were also discussed.
文摘Expression of the adhesion molecules, ICAM-1, VCAM-1, NCAM, CD44, CD49d (VLA-4, a chain), and CDlla (LFA-1, a chain) on mouse oocytes, and pre- and peri-implantation stage embryos was examined by quantitative indirect immunofluorescence microscopy. ICAM-1 was most strongly expressed at the oocyte stage, gradually declining almost to undetectable levels by the expanded blastocyst stage. NCAM, also expressed maximally on the oocyte, declined to undetectable levels beyond the morula stage. On the other hand, CD44 declined from highest expression at the oocyte stage to show a second maximum at the compacted 8-cell/morula. This molecule exhibited high expression around contact areas between trophecto-derm and zona pellucida during blastocyst hatching. CD49d was highly expressed in the oocyte, remained significantly expressed throughout and after blastocyst hatching was expressed on the polar trophecto-derm. Like CD44, CD49d declined to undetectable levels at the blastocyst outgrowth stage. Expression of both VCAM-1 and CDlla was undetectable throughout. The diametrical temporal expression pattern of ICAM-1 and NCAM compared to CD44 and CD49d suggest that dynamic changes in expression of adhesion molecules may be important for interaction of the embryo with the maternal cellular environment as well as for continuing development and survival of the early embryo.
文摘Mature eggs (at metaphase Ⅱ stage) produce a series of Ca2+ oscillation at fertilization. To define whether the fertilization-induced Ca2+ oscillation is restrict to the metaphase Ⅱ eggs and cell cycle dependent, mouse oocytes at prophase Ⅰ (arrested at germinal vesicle stage),metaphase Ⅰ, metaphase Ⅱ, as well as the pronuclear embryos at interphase of the first mitotic division derived from fertilization or parthenogenetic activation were inseminated after removal of zona pellucida. The results show that the fertilization-induced Ca2+ oscillation is not specific to metaphase Ⅱ eggs. This is supported by the fact that immature oocytes generated the Ca2+ oscillations at fertilization regardless of their nuclear progression from prophase Ⅰ to metaphase Ⅰ (in vitro matured) stage. More interestingly, it was first found that pronuclear embryos at interphase derived from parthenogenetic activation showed Ca2+ oscillations in response to fertilization while the zygotes at interphase did not after reinsemination or intracytoplasmic injection of sperm extracts which induce Ca2+ oscillations in MII eggs. This suggests that the ability of oocytes to generate Ca2+ oscillation in response to sperm penetration is not regulated in a cell cycle dependent manner but dependent on the cytoplasmic maturation.
文摘Mouse oocytes undergo polarization during meiotic maturation, and this polarization is essential for asymmetric cell divisions that maximize retention of maternal components required for early development. Without conventional centrosomes, the meiotic spindle has less focused poles and is barrel-shaped. The migration of meiotic spindles to the cortex is accompanied by a local reorganization and polarization of the cortex. LGN is a conserved protein involved in cell polarity and regulation of spindle organization. In the present study, we characterized the localization dynamics of LGN during mouse oocyte maturation and analyzed the effects of LGN upregulation and downregulation on meiotic spindle organization. At the germinal vesicle stage, LGN is distributed both cytoplasmically and at the cortex. During maturation, LGN localizes to the meiotic spindle apparatus and cortical LGN becomes less concentrated at the actin cap region. Excessive LGN induces meiotic spindle organization defects by elongating the spindle and enhancing pole focusing, whereas depletion of LGN by RNA interference results in meiotic spindle deformation and chromosome misalignment. Furthermore, the N-terminus of LGN has the ability of full-length LGN to regulate spindle organization, whereas the C-terminus of LGN controls cortical localization and polarization. Our results reveal that LGN is cortically polarized in mouse oocytes and is critical for meiotic spindle organization.
基金Supported by the National Natural Science Foundation of China,No. 39970374
文摘AIM: Hepatitis B is a worldwide public health problem. To explore the feasibility of hepatitis B virus (HBV) vertical transmission via oocytes, the presence and integration of HBV DNA in mouse oocytes were studied. METHODS: Genomic DNA was isolated and metaphases were prepared, respectively from mouse oocytes cocultured with pBR322-HBV DNA plasmids. PCR, Southern blot, dot hybridization and fluorescence in situ hybridization (FISH) were performed to explore the existence and integration of HBV DNA in oocytes.RESULTS: PCR detected positive bands in the tested samples, and then Southern blot revealed clear hybridization signals in PCR products. Final washing solutions were collected for dot hybridization and no signal for HBV DNA was observed, which excluded the possibility that contamination of washing solutions gave rise to positive results of PCR and Southern blot. FISH demonstrated that 36 of 1 000 metaphases presented positive signals. CONCLUSION: HBV DNA sequences are able to pass through the zona and oolemma to enter into oocytes and tointegrate into their chromosomes. HBV DNA sequences might be brought into embryo via oocytes as vectors when they are fertilized with normal spermatozoa.
文摘Although the role of oxidative stress in maternal aging and infertility has been suggested, the underlying mechanisms are not fully understood. The present study is designed to determine the relationship between mitochondrial function and spindle stability in metaphase II (MII) oocytes under oxidative stress. MII mouse oocytes were treated with H2O2 in the presence or absence of permeability transition pores (PTPs) blockers cyclosporin A (CsA). In addition, antioxidant N-acetylcysteine (NAC), F0/F1 synthase inhibitor oligomycin A, the mitochondria uncoupler carbonyl cyanide 4-trifluoro- methoxyphenylhydrazone (FCCP) or thapsigargin plus 2.5 mM Ca^2+ (Th+2.5 mM Ca^2+) were used in mechanistic studies. Morphologic analyses of oocyte spindles and chromosomes were performed and mitochondrial membrane potential (AWm), cytoplasmic free calcium concentration ([Ca^2+]c) and cytoplasmic ATP content within oocytes were also assayed. In a time- and H202 dose-dependent manner, disruption of meiotic spindles was found after oocytes were treated with H202, which was prevented by pre-treatment with NAC. Administration of H2O2 led to a dissipation of AWm, an increase in [Ca^2+]c and a decrease in cytoplasmic ATP levels. These detrimental responses of oocytes to H2O2 treatment could be blocked by pre-incubation with CsA. Similar to H2O2, both oligomycin A and FCCP dissipated AWm, decreased cytoplasmic ATP contents and disassembled MII oocyte spindles, while high [Ca^2+]c alone had no effects on spindle morphology. In conclusion, the decrease in mitochondria-derived ATP during oxidative stress may cause a disassembly of mouse MII oocyte spindles, presumably due to the opening of the mitochondrial PTPs.
文摘This research focused using novel substrate, longan Lactobacillus casei subsp, rhamnosus TISTR 108. The optimum juice as carbon source for continuous lactic acid production by medium for lactic acid production was pure longan juice with 120 g/L sugar concentration and among the different nitrogen sources were added to the longan juice (yeast extract, tryptic soy, urea, (NH4)2SO4 and NaNO3), yeast extract had the most efficiency. Yeast extract (10 g/L) without adding minerals to longan juice could produced the maximum lactic acid concentration of 38.91 ± 0.190 g/L in 60 h and the yield of 0.460± 0.122 g/g with the productivity of 0.649± 0.002 g/Lh in 2 liters flask. Batch fermentation was conducted in 2 liters fermentor and 41.38± 0.030 g/L lactic acid was produced in 48 h with the yield of 0.398 ± 0.215 g/g and the productivity was 0.862 ± 0.001 g/L h. The continuous fermentation using 2 liters fermentor as a high productivity for lactic acid (1.091 ± 0.001 g/L h) was achieved at dilution rate (D) of 0.0685 h-1.
文摘AIM:To investigate the effects of Saccharomyces boulardii(S.boulardii) in an experimental rat model of trinitrobenzene sulfonic acid(TNBS)-induced colitis.METHODS:Thirty-two Wistar albino female rats were categorized into five groups.On the first day of the study,50 mg TNBS was administered via a rectal catheter in order to induce colitis in all rats,except those in the control group.For 14 d,the rats were fed a standard diet,without the administration of any additional supplements to either the control or TNBS groups,in addition to 1 mg/kg per day S.boulardii to the S.boulardii group,1 mg/kg per day methyl prednisolone(MP) to the MP group.The animals in the S.boulardii + MP group were coadministered these doses of S.boulardii and MP.During the study,weight loss,stool consistency,and the presence of obvious blood in the stool were evaluated,and the disease activity index(DAI) for colitis was recorded.The intestines were examined and colitis was macro-and microscopically scored.The serum and tissue levels of tumor necrosis factor-α(TNF-α) and nitric oxide(NO) were determined,and fungemia was evaluated in the blood samples.RESULTS:The mean DAI scores for the MP and S.boulardii + MP groups was significantly lower than the TNBS group(3.69 ± 0.61 vs 4.46 ± 0.34,P = 0.018 and 3.77 ± 0.73 vs 4.46 ± 0.34,P = 0.025,respectively).While no significant differences between the TNBS and the S.boulardii or MP groups could be determined in terms of serum NO levels,the level of serum NO in the S.boulardii + MP group was significantly higher than in the TNBS and S.boulardii groups(8.12 ± 4.25 μmol/L vs 3.18 ± 1.19 μmol/L,P = 0.013;8.12 ± 4.25 μmol/L vs 3.47 ± 1.66 μmol/L,P = 0.012,respectively).The tissue NO levels in the S.boulardii,MP and S.boulardii + MP groups were significantly lower than the TNBS group(16.62 ± 2.27 μmol/L vs 29.72 ± 6.10 μmol/L,P = 0.002;14.66 ± 5.18 μmol/Lvs 29.72 ± 6.10 μmol/L,P = 0.003;11.95 ± 2.34 μmol/Lvs 29.72 ± 6.10 μmol/L,P = 0.002,respectively).The tissue NO levels in the S.boulardii,MP and S.boulardii + MP groups were similar.The mean serum and tissue TNF-α levels were determined to be 12.97 ± 18.90 pg/mL and 21.75 ± 15.04 pg/mL in the control group,18.25 ± 15.44 pg/mL and 25.27 ± 11.95 pg/mL in the TNBS group,20.59 ± 16.15 pg/mL and 24.39 ± 13.06 pg/mL in the S.boulardii group,9.05 ± 5.13 pg/mL and 24.46 ± 10.85 pg/mL in the MP group,and 13.95 ± 10.17 pg/mL and 24.26 ± 10.37 pg/mL in the S.boulardii + MP group.Significant differences in terms of the levels of serum and tissue TNF-α and the macroscopic and microscopic scores were not found between the groups.S.boulardii fungemia was not observed in any of the rats.However,Candida fungemia was detected in one rat(14%) in the TNBS group,two rats(28%) in the S.boulardii group,three rats(50%) in the MP group,and three rats(42%) in S.boulardii + MP group.CONCLUSION:S.boulardii does not demonstrate considerable effects on the DAI,pathological scores,or cytokine levels but does decrease the tissue NO levels.
文摘On Nov 17th,a team of researchers from the Shanghai Institute of Biochemistry and Cell Biology(SIBCB),Shanghai Institutes for Biological Sciences,CAS led by Prof.LI Jinsong reports online in Cell Research a novel technique to induce from mice oocytes haploid embryonic stems cells(haESCs)that can fully replace the reproductive functions of sperms,greatly simplifying the otherwise complicated techniques to produce such stem cells and semi-cloned(SC)mice.It is anticipated that this will further facilitate research in the field of stem cells and embryonic development;
文摘[Objective ] The study aimed to provide a theoretical basis for the clinical application of collagen peptide from Cyanea nozakii. [ Method] After acute toxicity test on mice, collagen peptide from C. nozakii were given to mice by continuous intragastric administration for 30 d at the doses of 25, 50, 100 mg/kg, and then the phagocytosis of macrophage, delayed type hypersensitivity (DTH) and serum hemolysin level were determined. [ Result] Collagen peptide from C. nozakii was atoxic or low toxic, and the three immune indices of experimental groups were signifi- canUy higher than those of the control group (treated with same volume of normal saline) at 0.05 or 0.01 level. E Conclusion] Collagen peptide from C. nozakii has a certain immunopotentiation.
文摘Recombinant human-salmon calcxtonin (hsCT) was synthesized and expressea on the cell surtaces ot recombinant Saccharomyces cerevisiae (yAGA2-hsCT) using the pAGA2-hsCT expression vector. Expression of recombinant hsCT was verified by flow cytometer.The resorption activity of osteoclasts was inhibited by recombinant hsCT protein which released from the cell surface of yAGA2-hsCT. Blood calcium determination in rats showed the activity of yAGA2-hsCT following oral administration of 5 mg/kg lyophilized transformant yeast to hypercalcemia rats decreases the serum calcium from 2.82 ±0.023 mM to 2.662 ± 0.012 mM.
文摘The ingestion of probiotic lactic acid bacteria has been evaluated and noted that it has an effect on the balance of desirable microbiota in the gastrointestinal tract. Lactobacillus gasseri demonstrates good survival in the gastrointestinal tract, and it has been associated with a variety of probiotic activities and roles, including the reduction of fecal mutagenic enzymes, the production of bacteriocins and the stimulation of macrophages immunomodulation. The aim of the study was to evaluate the effects of a pool of L. gasseri strains isolated from the feces of breastfed infants added in the human milk of healthy women. The milk was both pasteurized and unpasteurized, to verify the cell cytotoxicity of macrophages and to quantify the production of immunologic mediators such as IL-4, IL-6, IFN-γ, TNF-α, NO and oxygen intermediary compounds (H2O2). The administration of raw human milk and pasteurized human milk to infants is a regular, encouraged practice in units of intensive therapy (UITs) and our present investigation verified the beneficial effect of addition of a pool of L. gasseri to pasteurized human milk (PHML). Our results show that probiotic supplementation helped to maintain cell viability, reduced IL-6 and IFN-γ production and stimulated TNF-α, NO, H2O2, IL-4 production. Nevertheless, the results indicate that the addition of lactobacillus to human milk was not a determinant in the production of TNF-α. L. gasseri added to breast milk did not present a cytotoxic risk, and the addition ofL. gasseri to pasteurized milk of human milk bank would benefit newborns that depend on milk banks for the colonization of more desirable microbiota.
文摘The presence of Geotrichum candidum in fresh cheese is considered to be a contaminant and may lead to the product spoilage. The oxidative yeast Candida maltosa firstly isolated from the spoiled fruit yoghurt surface in Slovakia belongs to the yeast contaminants of fermented dairy products. The effect of the cultivation temperature and the presence of Lactobacillus rhamnosus GG on the growth of dairy spoilage yeasts in ultrapasteurized milk was studied. Addition of Lb. rhamnosus GG in milk caused partial inhibition of the yeast growth dynamics in milk. The water activity transformation of Gibson model after the temperature modification (Tw) was applied to model growth dynamics of G. candidum in pure and mixed culture, respectively: In μ_Gc=-5.0376+2.7281 Tw-0.4217Tw^2, lnμ_CC_LGG=-6.0033+3.2996Tw-0.5553Tw^2. The effect of different Lb. rhamnosus GG addition and the incubation temperature on the C. maltosa growth dynamics was analyzed by linear regression methodology and described by using following equations: lnGr1=-5.3674+0.2341T+0.2599N0-0.0032T^2-0.0492N0^2-0.0068TN0 and lnGr11=-9.5457-0.249T+2.3823N0 +0.0099T^2-0.2324N0^2+0.0098TN0 Based on the principles of predictive microbiology, the mutual microbial interactions and potential application of the lactobacillus strains in food protection are discussed.