{"title":"Quality Control of Mineral Oil Used for Embryo Culture","authors":"J. Otsuki","doi":"10.1274/JMOR.24.175","DOIUrl":"https://doi.org/10.1274/JMOR.24.175","url":null,"abstract":"","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"117 1","pages":"175-176"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77619414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cryopreservation of Human Embryos by Vitrification Method","authors":"M. Motoishi, Shin'ichi Kobayashi","doi":"10.1274/JMOR.24.65","DOIUrl":"https://doi.org/10.1274/JMOR.24.65","url":null,"abstract":"","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"13 1","pages":"65-66"},"PeriodicalIF":0.0,"publicationDate":"2007-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88882925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to develop an in-vitro assay system for detection of cytogenetic toxicity of chemicals, we cultured mouse oocytes in vitro with two kinds of spindle poisons, carbendazim (MBC) and griseofulvin (GF). When cultured for 15 h with MBC (6 μg/ml), the majority of the oocytes arrested maturation at the metaphase in the first meiosis. This effect of MBC could be achieved with the latter half of the exposure during 15 h for the entire culture. In contrast, a significant proportion of the oocytes cultured with GF (10 μg/ml) could not continue meiosis from the germinal vesicle stage. Therefore, we characterized the difference in the effects of MBC and GF on meiotic progression of mouse oocytes by using this in-vitro assay system, demonstrating that the system would be useful for detection of cytogenetic toxicity of chemicals.
{"title":"A Novel Assay System of Chemicals Using In-vitro Maturation of Mouse Oocytes: Effects of Carbendazim and Griseofulvin","authors":"Ryota Tanaka, T. Sasanami, M. Toriyama, M. Mori","doi":"10.1274/JMOR.21.123","DOIUrl":"https://doi.org/10.1274/JMOR.21.123","url":null,"abstract":"In order to develop an in-vitro assay system for detection of cytogenetic toxicity of chemicals, we cultured mouse oocytes in vitro with two kinds of spindle poisons, carbendazim (MBC) and griseofulvin (GF). When cultured for 15 h with MBC (6 μg/ml), the majority of the oocytes arrested maturation at the metaphase in the first meiosis. This effect of MBC could be achieved with the latter half of the exposure during 15 h for the entire culture. In contrast, a significant proportion of the oocytes cultured with GF (10 μg/ml) could not continue meiosis from the germinal vesicle stage. Therefore, we characterized the difference in the effects of MBC and GF on meiotic progression of mouse oocytes by using this in-vitro assay system, demonstrating that the system would be useful for detection of cytogenetic toxicity of chemicals.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"13 1","pages":"123-127"},"PeriodicalIF":0.0,"publicationDate":"2004-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81393896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nuclear reprogramming is a phenomenon regulated by complex mechanisms that lead to the restoration of pluripotential competence in specialized somatic nuclei. Nuclear reprogramming is induced by changes in epigenet ic modif icat ions, known col lect ively as ep igene t i c rep rog ramming . I n somat i c ce l l development, on-off switching of certain key genes, which function in determining cell fate in a particular d i r ec t i on , i s r egu la ted t h rough ep igene t i c reprogramming in restricted regions of the genome. In nuclear reprogramming, genome-wide epigenetic reprogramming, which triggers a global restoration of ep igene t i c memory i n the genome lead ing to transformation from a specified to a default nuclear s t a te , i s c ruc ia l . Genome-w ide ep igene t i c reprogramming occurs in nuclear reprogramming with the nuclear transfer of somatic cells to enucleated oocytes and via cell hybridization between embryonic stem cells and adult somatic cells, and also in germ cell and early embryonic development but not in somatic cell development. Global chromatin de-condensation marked by h is tone H3 lys ine 4 methy la t ion is mechanistically linked with the genome-wide epigenetic reprogramming. At least two steps; 1) erasure of the somatic epigenotype induced by the genome-wide epigenetic reprogramming and 2) establishment of a plur ipotent ial cel l -specif ic epigenotype by local epigenetic reprogramming through the activity of key players including Oct4, Sox2, Ehz2 and Nanog, may be required for conferring and maintaining pluripotential competence in the reprogrammed somatic nuclei. Nuclear Reprogramming in Early Embryonic Development
{"title":"\"Nuclear Reprogramming\" and \"Epigenetic Reprogramming\"","authors":"T. Tada, H. Kimura, M. Tada","doi":"10.1274/JMOR.21.97","DOIUrl":"https://doi.org/10.1274/JMOR.21.97","url":null,"abstract":"Nuclear reprogramming is a phenomenon regulated by complex mechanisms that lead to the restoration of pluripotential competence in specialized somatic nuclei. Nuclear reprogramming is induced by changes in epigenet ic modif icat ions, known col lect ively as ep igene t i c rep rog ramming . I n somat i c ce l l development, on-off switching of certain key genes, which function in determining cell fate in a particular d i r ec t i on , i s r egu la ted t h rough ep igene t i c reprogramming in restricted regions of the genome. In nuclear reprogramming, genome-wide epigenetic reprogramming, which triggers a global restoration of ep igene t i c memory i n the genome lead ing to transformation from a specified to a default nuclear s t a te , i s c ruc ia l . Genome-w ide ep igene t i c reprogramming occurs in nuclear reprogramming with the nuclear transfer of somatic cells to enucleated oocytes and via cell hybridization between embryonic stem cells and adult somatic cells, and also in germ cell and early embryonic development but not in somatic cell development. Global chromatin de-condensation marked by h is tone H3 lys ine 4 methy la t ion is mechanistically linked with the genome-wide epigenetic reprogramming. At least two steps; 1) erasure of the somatic epigenotype induced by the genome-wide epigenetic reprogramming and 2) establishment of a plur ipotent ial cel l -specif ic epigenotype by local epigenetic reprogramming through the activity of key players including Oct4, Sox2, Ehz2 and Nanog, may be required for conferring and maintaining pluripotential competence in the reprogrammed somatic nuclei. Nuclear Reprogramming in Early Embryonic Development","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"13 1","pages":"97-104"},"PeriodicalIF":0.0,"publicationDate":"2004-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73878578","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Hashimoto, Sakae Goto, Mikihiko Tsubouchi, Y. Izumi, Y. Yoshimura, Y. Kasahara, M. Shiotani
The purpose of this study is to determine criteria of split ICSI in which half of oocytes were inseminated by ICSI and half by conventional IVF. Six hundreds eighty-two couples who experienced the first assisted reproductive technology in our clinic were enrolled in the study. Pregnancy rate in couples with fertilization rate (FR) less than 30% was significantly lower than that in couples with FR exceeding 50%. FR in couples with oligozoospermia (sperm count < 20 × 106/ml) (50.0~53.8%) was significantly lower than that in couples with normozoospermia (65.0~79.5%). FR in couples with sperm motility rate less than 20% (0~29.6%) were significantly lower than that in couples with motility rate exceeding 20% (66.8~76.8%). Infertile couples with oligozoospermic semen or low sperm motility rate (<20%) should be treated by split ICSI rather than by IVF.
{"title":"Indication for Split ICSI in Our Clinic","authors":"H. Hashimoto, Sakae Goto, Mikihiko Tsubouchi, Y. Izumi, Y. Yoshimura, Y. Kasahara, M. Shiotani","doi":"10.1274/JMOR.21.209","DOIUrl":"https://doi.org/10.1274/JMOR.21.209","url":null,"abstract":"The purpose of this study is to determine criteria of split ICSI in which half of oocytes were inseminated by ICSI and half by conventional IVF. Six hundreds eighty-two couples who experienced the first assisted reproductive technology in our clinic were enrolled in the study. Pregnancy rate in couples with fertilization rate (FR) less than 30% was significantly lower than that in couples with FR exceeding 50%. FR in couples with oligozoospermia (sperm count < 20 × 106/ml) (50.0~53.8%) was significantly lower than that in couples with normozoospermia (65.0~79.5%). FR in couples with sperm motility rate less than 20% (0~29.6%) were significantly lower than that in couples with motility rate exceeding 20% (66.8~76.8%). Infertile couples with oligozoospermic semen or low sperm motility rate (<20%) should be treated by split ICSI rather than by IVF.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"34 1","pages":"209-213"},"PeriodicalIF":0.0,"publicationDate":"2004-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85736126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
During meiosis and fertilization, gene expression in differentiated gametes is reprogrammed to allow the initiation of a new program from the totipotent zygotic genome. This remarkable transformation entails the deletion of the maternal and paternal gene expression profiles before or just after fertilization. Although reprogramming of gene expression plays an important role in relaying the genome to the next generation, the molecular mechanism of reprogramming remains unknown. Recently, cloned animals were generated in several species by transferring the nuclei of somatic cells into enucleated metaphase II (MII) oocytes [18]. The success of these experiments demonstrates that the MII oocyte cytoplasm has the ability to reprogram gene expression, but there is little information on the molecular events in the genome of the transferred nucleus during the reprogramming process. During reprogramming, the gene expression patterns in the differentiated oocytes should be erased, thereby establishing a totipotent gene expression pattern for fu r ther deve lopment . On the o ther hand , the discrimination of the paternal and maternal genomes should be maintained during genome reprogramming, s ince the paterna l and materna l genomes are functionally asymmetric in mammals. In this review, we describe our recent findings on the changes in the epigenetic modifications of differentiated genomes of oocytes during meiosis, and of somatic nuclei after transfer into oocytes, with special emphasis on the mechanism underlying the reprogramming of gene expression. We highlight two aspects of gene expression in the differentiated oocytes. The first involves erasure of information, and the second involves retention of information during meiosis and fertilization, while gene expression is reprogrammed. Some potential applications of these new findings are discussed.
{"title":"Mechanism of Gene Expression Reprogramming during Meiotic Maturation and Pre-Implantation Development","authors":"Jin-moon Kim, F. Aoki","doi":"10.1274/JMOR.21.89","DOIUrl":"https://doi.org/10.1274/JMOR.21.89","url":null,"abstract":"During meiosis and fertilization, gene expression in differentiated gametes is reprogrammed to allow the initiation of a new program from the totipotent zygotic genome. This remarkable transformation entails the deletion of the maternal and paternal gene expression profiles before or just after fertilization. Although reprogramming of gene expression plays an important role in relaying the genome to the next generation, the molecular mechanism of reprogramming remains unknown. Recently, cloned animals were generated in several species by transferring the nuclei of somatic cells into enucleated metaphase II (MII) oocytes [18]. The success of these experiments demonstrates that the MII oocyte cytoplasm has the ability to reprogram gene expression, but there is little information on the molecular events in the genome of the transferred nucleus during the reprogramming process. During reprogramming, the gene expression patterns in the differentiated oocytes should be erased, thereby establishing a totipotent gene expression pattern for fu r ther deve lopment . On the o ther hand , the discrimination of the paternal and maternal genomes should be maintained during genome reprogramming, s ince the paterna l and materna l genomes are functionally asymmetric in mammals. In this review, we describe our recent findings on the changes in the epigenetic modifications of differentiated genomes of oocytes during meiosis, and of somatic nuclei after transfer into oocytes, with special emphasis on the mechanism underlying the reprogramming of gene expression. We highlight two aspects of gene expression in the differentiated oocytes. The first involves erasure of information, and the second involves retention of information during meiosis and fertilization, while gene expression is reprogrammed. Some potential applications of these new findings are discussed.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"36 1","pages":"89-96"},"PeriodicalIF":0.0,"publicationDate":"2004-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74508518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mamoru Tanaka, Takahide Teranishi, Masataka Furuya, Yudai Tanaka, K. Minegishi, K. Miyakoshi, H. Ishimoto, Y. Yoshimura
The term epigenetics defines all meiotically and mitotically heritable changes in gene expression that are not coded in the DNA sequence itself. Epigenetic modification of the genome ensures proper gene activation during development and involves genomic methylation changes, the assembly of histones and histone variants into nucleosomes, and remodeling of other chromatin associated proteins such as linker histones and transcription factors [1]. Additionally, the economic and medical implications of widespread cloning of domestic animals by nuclear transfer have greatly stimulated interest in the basic molecular mechan i sms i nvo l ved i n r ep rog ramming t he developmental fate of nuclei introduced into eggs and oocytes [2]. An understanding of these mechanisms not only wi l l provide insight into the signi f icance of epigenetic events in establishing a developmental program, but also suggests new approaches towards improving the efficiency of nuclear transfer procedures. The fundamental structural unit of chromatin is an assemblage, called the nucleosome, composed of five types of histones (designated H1, H2A, H2B, H3, and H4) and DNA. A nucleosome consists of approximately 1.8 turns of DNA wound around a core particle of histone proteins. The core particle is an octamer of 4 types of histones: two each of the H2A, H2B, H3, and H4 proteins. Approximately 166 base pairs are bound to the nucleosome: 146 base pairs are tightly bound to the core particle and the remaining 20 base pairs are associated with the H1 histone [3]. This nucleosome structure is closely similar in all eukaryotes. Although the f ie ld of chromatin research has focused on modifications to core histones that signal different gene expression states, it is becoming clear that different subtypes of histones are also important. Recently, Lee et al. demonstrate how a linker histone, H1b, can specifically repress the expression of a regulator of skeletal muscle differentiation, the MyoD gene, and thereby restrain the developmental decision to make muscle [4]. They speculate that the complexity of H1 function is attributed, in part, to differential activities of its isoforms.
{"title":"Chromatin Remodeling with Oocyte-specific Linker Histones","authors":"Mamoru Tanaka, Takahide Teranishi, Masataka Furuya, Yudai Tanaka, K. Minegishi, K. Miyakoshi, H. Ishimoto, Y. Yoshimura","doi":"10.1274/JMOR.21.82","DOIUrl":"https://doi.org/10.1274/JMOR.21.82","url":null,"abstract":"The term epigenetics defines all meiotically and mitotically heritable changes in gene expression that are not coded in the DNA sequence itself. Epigenetic modification of the genome ensures proper gene activation during development and involves genomic methylation changes, the assembly of histones and histone variants into nucleosomes, and remodeling of other chromatin associated proteins such as linker histones and transcription factors [1]. Additionally, the economic and medical implications of widespread cloning of domestic animals by nuclear transfer have greatly stimulated interest in the basic molecular mechan i sms i nvo l ved i n r ep rog ramming t he developmental fate of nuclei introduced into eggs and oocytes [2]. An understanding of these mechanisms not only wi l l provide insight into the signi f icance of epigenetic events in establishing a developmental program, but also suggests new approaches towards improving the efficiency of nuclear transfer procedures. The fundamental structural unit of chromatin is an assemblage, called the nucleosome, composed of five types of histones (designated H1, H2A, H2B, H3, and H4) and DNA. A nucleosome consists of approximately 1.8 turns of DNA wound around a core particle of histone proteins. The core particle is an octamer of 4 types of histones: two each of the H2A, H2B, H3, and H4 proteins. Approximately 166 base pairs are bound to the nucleosome: 146 base pairs are tightly bound to the core particle and the remaining 20 base pairs are associated with the H1 histone [3]. This nucleosome structure is closely similar in all eukaryotes. Although the f ie ld of chromatin research has focused on modifications to core histones that signal different gene expression states, it is becoming clear that different subtypes of histones are also important. Recently, Lee et al. demonstrate how a linker histone, H1b, can specifically repress the expression of a regulator of skeletal muscle differentiation, the MyoD gene, and thereby restrain the developmental decision to make muscle [4]. They speculate that the complexity of H1 function is attributed, in part, to differential activities of its isoforms.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"11 1","pages":"82-88"},"PeriodicalIF":0.0,"publicationDate":"2004-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73753948","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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