This study was conducted to investi- gate the pattern of DNA methylation in pronuclearstage mouse embryos derived from vitrified-warmed oocytes. Mouse oocytes at metaphase II （MII） stage of meiosis were allocated ra...This study was conducted to investi- gate the pattern of DNA methylation in pronuclearstage mouse embryos derived from vitrified-warmed oocytes. Mouse oocytes at metaphase II （MII） stage of meiosis were allocated randomly into three groups： 1） untreated （control）; 2 ） exposed to vitrification solution without being plunged into liquid nitrogen （toxicity）; and 3 ） vitrified by open-pulled straw （OPS） method （vitrification）. Oocytes were fertilized in vitro （IVF）. The level of DNA methylation was examined at 8 hpf （hours post-fertilization） by immunofluorescence using an anti-5-methylcytosine （5-MeC） monoclonal antibody and fluorescein isothiocyanate （FITC）-conjugated goat anti-mouse IgG. After IVF, rates of 2-cell embryos （ 51.39% ） and blastocysts （35.82%） for vitrified-warmed oocytes were lower （P〈0.01） than that for control （70.83%, 47.82% ） or vitrification solution treated （64.80%, 46.29% ） oocytes. At 8 hpf, there were more （P 〈 0.05） pronuclear-stage oocytes in which syngamy of pronuclei had not occurred in the vitrifica- tion group. In addition, 5-MeC fluorescent intensities for the female pronucleus and zygote were lower in the vitrification group （P 〈0.01 ） compared to pronuclear-stage embryos in the control and toxicity groups. In conclusion, oocyte vitrification causes a reduction in global genomic methylation in the female pronucleus and zygote, resulting in delayed fusion of pronuclei and compromising the developmental potential of mouse zygotes and embryos.展开更多
Background： In order to improve ICSI, appropiate sperm selection and oocyte activation is necessary. The objective of the present study was to determine the efficiency of fertilization using ICSI with chemically acti...Background： In order to improve ICSI, appropiate sperm selection and oocyte activation is necessary. The objective of the present study was to determine the efficiency of fertilization using ICSI with chemically activated ovine oocytes and sperm selected by swim up（SU） or swim up ＋ zona pellucida（SU ＋ ZP） binding.Results： Experiment 1, 4–20 replicates with total 821 in vitro matured oocytes were chemically activated with ethanol, calcium ionophore or ionomycin, to determine oocyte activation（precense of one PN）. Treatments showed similar results（54, 47, 42 %, respectively） but statistically differents（P 0.05）.Conclusions： Chemical activation induces higher ovine oocyte activation than mechanical activation. Ethanol slightly displays higher oocyte activation than calcium ionophore and ionomicine. Sperm selection with SU ＋ ZP increased AR/A and AR/D rates in comparison with SU in fresh and frozen-thawed sperm. According to this, in terms of fertilization rates, chemical activation after ICSI increased oocyte PN formation compared to mechanical activation. Also, fresh sperm treated with SU and SU ＋ ZP were significantly different than frozen-thawed sperm,but between sperm treatments no significant differences were obtained.展开更多
Objective To determine the function of, in vivo, renin and its role in the pathogenesis of hypertension. Methods A renin 2 gene restriction map was constructed by endonuclease digest ion and Southern blotting hy...Objective To determine the function of, in vivo, renin and its role in the pathogenesis of hypertension. Methods A renin 2 gene restriction map was constructed by endonuclease digest ion and Southern blotting hybridization. Transgenic rats were produced via micro injection method.Results The 24 kb fragments containing mouse full length ren 2 and it s flanking sequence were cleaved by single enzymes (EcoRⅠ, KpnⅠ and BamHⅠ) an d combined enzymes (EcoRⅠ/KpnⅠ, KpnⅠ/BamHⅠ and BamHⅠ/EcoRⅠ), respectively. The digests were electrophoresed in 0.8% agarose plates and transferred onto NC membranes. Radioactive 735 bp and 1400 bp probes obtained from half and full l ength renin 1 cDNA were used in southern blotting hybridization. According to t he electrophoresis and hybridization patterns, a ren 2 restriction map was cons tructed. 1603 fertilized rat ova after injection with purified 24 kb renin 2 ge ne were implanted into the oviducts of 81 pseudopregnant recipients in about 2 0 ova per female rat. 306 progenies were obtained from 50 foster mothers (averag e of pregnancies was 56.6%). 248 survived pups were identified by PCR analys is and Southern hybridization, and eight positive rats were found to be the transgenic rats (founder, F). All of them carried long fragments (24 kb) of renin 2 gene with normal blood pressure. Preliminary breeding and screening were carried out in the founder. Total survival pups (17.8%) and overall efficiencies (1%) were h arvested as the same as those reported in the literatures. A systemic observatio n and the problems occurred during production of transgenic rats were also descr ibed besides the technique procedure used in this study.Conclusions Mapping of full length murine ren 2 can be used in invest igation of the structure and function of the gene. The results denoted that the ren 2 tran sgenic rats were successfully established in this study and the technique used i n the production of transgenic rats was proved to be valid in leading to wide s pread application of transgenic technique to many other related researches.展开更多
文摘This study was conducted to investi- gate the pattern of DNA methylation in pronuclearstage mouse embryos derived from vitrified-warmed oocytes. Mouse oocytes at metaphase II （MII） stage of meiosis were allocated randomly into three groups： 1） untreated （control）; 2 ） exposed to vitrification solution without being plunged into liquid nitrogen （toxicity）; and 3 ） vitrified by open-pulled straw （OPS） method （vitrification）. Oocytes were fertilized in vitro （IVF）. The level of DNA methylation was examined at 8 hpf （hours post-fertilization） by immunofluorescence using an anti-5-methylcytosine （5-MeC） monoclonal antibody and fluorescein isothiocyanate （FITC）-conjugated goat anti-mouse IgG. After IVF, rates of 2-cell embryos （ 51.39% ） and blastocysts （35.82%） for vitrified-warmed oocytes were lower （P〈0.01） than that for control （70.83%, 47.82% ） or vitrification solution treated （64.80%, 46.29% ） oocytes. At 8 hpf, there were more （P 〈 0.05） pronuclear-stage oocytes in which syngamy of pronuclei had not occurred in the vitrifica- tion group. In addition, 5-MeC fluorescent intensities for the female pronucleus and zygote were lower in the vitrification group （P 〈0.01 ） compared to pronuclear-stage embryos in the control and toxicity groups. In conclusion, oocyte vitrification causes a reduction in global genomic methylation in the female pronucleus and zygote, resulting in delayed fusion of pronuclei and compromising the developmental potential of mouse zygotes and embryos.
文摘Background： In order to improve ICSI, appropiate sperm selection and oocyte activation is necessary. The objective of the present study was to determine the efficiency of fertilization using ICSI with chemically activated ovine oocytes and sperm selected by swim up（SU） or swim up ＋ zona pellucida（SU ＋ ZP） binding.Results： Experiment 1, 4–20 replicates with total 821 in vitro matured oocytes were chemically activated with ethanol, calcium ionophore or ionomycin, to determine oocyte activation（precense of one PN）. Treatments showed similar results（54, 47, 42 %, respectively） but statistically differents（P 0.05）.Conclusions： Chemical activation induces higher ovine oocyte activation than mechanical activation. Ethanol slightly displays higher oocyte activation than calcium ionophore and ionomicine. Sperm selection with SU ＋ ZP increased AR/A and AR/D rates in comparison with SU in fresh and frozen-thawed sperm. According to this, in terms of fertilization rates, chemical activation after ICSI increased oocyte PN formation compared to mechanical activation. Also, fresh sperm treated with SU and SU ＋ ZP were significantly different than frozen-thawed sperm,but between sperm treatments no significant differences were obtained.
文摘Objective To determine the function of, in vivo, renin and its role in the pathogenesis of hypertension. Methods A renin 2 gene restriction map was constructed by endonuclease digest ion and Southern blotting hybridization. Transgenic rats were produced via micro injection method.Results The 24 kb fragments containing mouse full length ren 2 and it s flanking sequence were cleaved by single enzymes (EcoRⅠ, KpnⅠ and BamHⅠ) an d combined enzymes (EcoRⅠ/KpnⅠ, KpnⅠ/BamHⅠ and BamHⅠ/EcoRⅠ), respectively. The digests were electrophoresed in 0.8% agarose plates and transferred onto NC membranes. Radioactive 735 bp and 1400 bp probes obtained from half and full l ength renin 1 cDNA were used in southern blotting hybridization. According to t he electrophoresis and hybridization patterns, a ren 2 restriction map was cons tructed. 1603 fertilized rat ova after injection with purified 24 kb renin 2 ge ne were implanted into the oviducts of 81 pseudopregnant recipients in about 2 0 ova per female rat. 306 progenies were obtained from 50 foster mothers (averag e of pregnancies was 56.6%). 248 survived pups were identified by PCR analys is and Southern hybridization, and eight positive rats were found to be the transgenic rats (founder, F). All of them carried long fragments (24 kb) of renin 2 gene with normal blood pressure. Preliminary breeding and screening were carried out in the founder. Total survival pups (17.8%) and overall efficiencies (1%) were h arvested as the same as those reported in the literatures. A systemic observatio n and the problems occurred during production of transgenic rats were also descr ibed besides the technique procedure used in this study.Conclusions Mapping of full length murine ren 2 can be used in invest igation of the structure and function of the gene. The results denoted that the ren 2 tran sgenic rats were successfully established in this study and the technique used i n the production of transgenic rats was proved to be valid in leading to wide s pread application of transgenic technique to many other related researches.
