Nuclear transfer (NT) involves transferring the nucleus from a diploid cell to an unfertilized egg from which the maternal nucleus has been removed. The NT technique involves several steps. The nucleus itself can be injected or the intact cell can be transferred into the oocyte. In the latter case, the oocyte and donor cell are normally fused and the reconstructed embryo activated by an electrical pulse. The reconstructed embryos are then cultured and those that appear to be developing normally are implanted into foster mothers. The NT technique was first used to clone sheep [1, 2] and cattle [3] by using cells taken directly from early embryos. In 1995, Campbell et al. [4] produced live lambs from embryo derived cells from a differentiated cell line that had been cultured for several weeks. In 1996, Wilmut et al. [5] created Dolly, the first animal cloned from a cell taken from an adult animal. Since then, although somatic cloned animals have been produced in several species [628], success rates remain low in all species, with published data showing that only 1% to 5% of reconstructed embryos result in l i ve b i r t hs ( see Ros l i n I ns t i t u te web s i t e [www.roslin.ac.uk/public/cloning.html]). Many cloned offspring die late in pregnancy or soon after birth [8, 29, 30], often from respiratory or cardiovascular dysfunction [3133]. Abnormal placental development [3441] is common and this is probably the major cause of fetal loss earlier in pregnancy [42]. Many of the cloned cattle and sheep that are born are much larger [29, 30, 43, 44] than normal and apparently normal clones may carry unrecognized abnormalities [45]. Differences Between Embryonic and Somatic Clones
{"title":"Animal Cloning : Reprogramming the Donor Genome","authors":"Seiya Takahashi","doi":"10.1274/JMOR.21.74","DOIUrl":"https://doi.org/10.1274/JMOR.21.74","url":null,"abstract":"Nuclear transfer (NT) involves transferring the nucleus from a diploid cell to an unfertilized egg from which the maternal nucleus has been removed. The NT technique involves several steps. The nucleus itself can be injected or the intact cell can be transferred into the oocyte. In the latter case, the oocyte and donor cell are normally fused and the reconstructed embryo activated by an electrical pulse. The reconstructed embryos are then cultured and those that appear to be developing normally are implanted into foster mothers. The NT technique was first used to clone sheep [1, 2] and cattle [3] by using cells taken directly from early embryos. In 1995, Campbell et al. [4] produced live lambs from embryo derived cells from a differentiated cell line that had been cultured for several weeks. In 1996, Wilmut et al. [5] created Dolly, the first animal cloned from a cell taken from an adult animal. Since then, although somatic cloned animals have been produced in several species [628], success rates remain low in all species, with published data showing that only 1% to 5% of reconstructed embryos result in l i ve b i r t hs ( see Ros l i n I ns t i t u te web s i t e [www.roslin.ac.uk/public/cloning.html]). Many cloned offspring die late in pregnancy or soon after birth [8, 29, 30], often from respiratory or cardiovascular dysfunction [3133]. Abnormal placental development [3441] is common and this is probably the major cause of fetal loss earlier in pregnancy [42]. Many of the cloned cattle and sheep that are born are much larger [29, 30, 43, 44] than normal and apparently normal clones may carry unrecognized abnormalities [45]. Differences Between Embryonic and Somatic Clones","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"42 1","pages":"74-81"},"PeriodicalIF":0.0,"publicationDate":"2004-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90254030","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}
Emiko Takaoka, Akiko Onitsukawaki, H. Tokunaga, Reiko Numata, Tetsuya Nomura
the indication of primary ICSI. In 639 cycles (356 cases) of conventional IVF, we examined the fertilization rate and pregnancy rate upon following items. Those were appearance and concentration of sperm, female age, and picked up oocyte. In the study of correlation between sperm concentration and rate of fertilization or pregnancy, the cases of sperm concentration less than 10 × 10 6 /ml were fertilized only 13.3% (18/135) or no cases were got pregnant (0/21). in the study of correlation between sperm motility rate and rate of fertilization or pregnancy, even in cases of motility rate less than 20%, fertilization rate was 33% (43/130) and pregnant rate was 19% (4/21). We also considered the sperm concentration after the swim up cases. In the cases sperm concentration less than 1 × 10 6 /ml, fertilization rate was only 2.3% (2/86) or no cases got pregnant (0/13). We could definite correlation between female ages or quantity of picked up oocyte and rate of fertilization and pregnancy respectively. that these are not applied to the indication of primary ICSI. We that the indication of primary ICSI should be on the sperm concentration and the numerical numbers were less than 10 × 10 6 /ml for ordinary cases and less than 1 × 10 6 /ml for after the swim up
{"title":"The Indication of Primary ICSI","authors":"Emiko Takaoka, Akiko Onitsukawaki, H. Tokunaga, Reiko Numata, Tetsuya Nomura","doi":"10.1274/JMOR.21.200","DOIUrl":"https://doi.org/10.1274/JMOR.21.200","url":null,"abstract":"the indication of primary ICSI. In 639 cycles (356 cases) of conventional IVF, we examined the fertilization rate and pregnancy rate upon following items. Those were appearance and concentration of sperm, female age, and picked up oocyte. In the study of correlation between sperm concentration and rate of fertilization or pregnancy, the cases of sperm concentration less than 10 × 10 6 /ml were fertilized only 13.3% (18/135) or no cases were got pregnant (0/21). in the study of correlation between sperm motility rate and rate of fertilization or pregnancy, even in cases of motility rate less than 20%, fertilization rate was 33% (43/130) and pregnant rate was 19% (4/21). We also considered the sperm concentration after the swim up cases. In the cases sperm concentration less than 1 × 10 6 /ml, fertilization rate was only 2.3% (2/86) or no cases got pregnant (0/13). We could definite correlation between female ages or quantity of picked up oocyte and rate of fertilization and pregnancy respectively. that these are not applied to the indication of primary ICSI. We that the indication of primary ICSI should be on the sperm concentration and the numerical numbers were less than 10 × 10 6 /ml for ordinary cases and less than 1 × 10 6 /ml for after the swim up","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"73 1","pages":"200-203"},"PeriodicalIF":0.0,"publicationDate":"2004-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82961979","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}
Vitrification has been focused on as a promising approach for human blastocyst cryopreservation, but few reports are available on the effect of assisted hatching (AH) in conjunction with human vitrified blastocyst transfers. Therefore, in this study, AH with acidic Tyrode was performed at the time of warming of vitrified blastocysts before transfer in order to improve the implantation and pregnancy rates. In the AH group, 13 clinical pregnancies (54.2%) and 15 implantations (36.6%) out of 41 blastocysts transferred were obtained. In the non-AH group, 1 clinical pregnancy (12.5%) and 1 implantation (6.7%) out of 15 blastocysts transferred were obtained. AH on the vitrified blastocysts after warming improved the implantation rate significantly (P<0.03). The pregnancy rate was also increased statistically in the AH group (P<0.05). The results suggest that the vitrification procedure may cause hardening of the zona pellucida and AH of vitrified blastocysts would be useful for clinical application.
{"title":"Assisted Hatching at the Time of Warming Improves Pregnancy and Implantation Outcomes for Vitrified Human Expanded Blastocyst Transfer","authors":"K. Hiraoka, K. Hiraoka, M. Kinutani, K. Kinutani","doi":"10.1274/JMOR.21.118","DOIUrl":"https://doi.org/10.1274/JMOR.21.118","url":null,"abstract":"Vitrification has been focused on as a promising approach for human blastocyst cryopreservation, but few reports are available on the effect of assisted hatching (AH) in conjunction with human vitrified blastocyst transfers. Therefore, in this study, AH with acidic Tyrode was performed at the time of warming of vitrified blastocysts before transfer in order to improve the implantation and pregnancy rates. In the AH group, 13 clinical pregnancies (54.2%) and 15 implantations (36.6%) out of 41 blastocysts transferred were obtained. In the non-AH group, 1 clinical pregnancy (12.5%) and 1 implantation (6.7%) out of 15 blastocysts transferred were obtained. AH on the vitrified blastocysts after warming improved the implantation rate significantly (P<0.03). The pregnancy rate was also increased statistically in the AH group (P<0.05). The results suggest that the vitrification procedure may cause hardening of the zona pellucida and AH of vitrified blastocysts would be useful for clinical application.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"52 1","pages":"118-122"},"PeriodicalIF":0.0,"publicationDate":"2004-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90843533","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}
Changes in the number of lipid droplets during meiotic maturation, fertilization and early development were histochemically examined in cultured porcine oocytes and embryos. The oocytes and embryos possessed Sudanophilic lipids composed of small (<2.5 μm), medium (2.5-4.9 μm) and large (≥5.0 μm) droplets. In oocytes soon after collection, the numbers of Sudanophilic lipid droplets with small and medium sizes were few and the number of those with large size was 148 ± 11.36. After being cultured for 22 and 44 hrs, the number of lipid droplets with large size remarkably decreased, while the number of those with small and medium sizes increased. The numbers of lipid droplets of each size in the oocytes 4 and 8 hrs after insemination were similar to those in oocytes 44 hrs after maturation culture. On the other hand, the number of lipid droplets in embryos did not vary greatly between the pronuclear and the 16-cell stages, but gradually decreased after the morula stage. Expanded blastocysts had few small and medium lipid droplets and 11 ± 1.68 large ones. The present findings confirmed that lipid droplets contained in oocytes become smaller in size and larger in number. Since the smaller lipid droplets appear not to be used in the process of fertilization, we presume that they are mainly used as an energy source for the formation and expansion of blastocysts.
{"title":"Histochemical Demonstration of Lipids in Cultured Porcine Oocytes and Preimplantation Embryos","authors":"H. Takano, S. Niimura","doi":"10.1274/JMOR.21.36","DOIUrl":"https://doi.org/10.1274/JMOR.21.36","url":null,"abstract":"Changes in the number of lipid droplets during meiotic maturation, fertilization and early development were histochemically examined in cultured porcine oocytes and embryos. The oocytes and embryos possessed Sudanophilic lipids composed of small (<2.5 μm), medium (2.5-4.9 μm) and large (≥5.0 μm) droplets. In oocytes soon after collection, the numbers of Sudanophilic lipid droplets with small and medium sizes were few and the number of those with large size was 148 ± 11.36. After being cultured for 22 and 44 hrs, the number of lipid droplets with large size remarkably decreased, while the number of those with small and medium sizes increased. The numbers of lipid droplets of each size in the oocytes 4 and 8 hrs after insemination were similar to those in oocytes 44 hrs after maturation culture. On the other hand, the number of lipid droplets in embryos did not vary greatly between the pronuclear and the 16-cell stages, but gradually decreased after the morula stage. Expanded blastocysts had few small and medium lipid droplets and 11 ± 1.68 large ones. The present findings confirmed that lipid droplets contained in oocytes become smaller in size and larger in number. Since the smaller lipid droplets appear not to be used in the process of fertilization, we presume that they are mainly used as an energy source for the formation and expansion of blastocysts.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"211 1","pages":"36-40"},"PeriodicalIF":0.0,"publicationDate":"2004-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85326501","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}
Chorionic villus sampling (CVS) is a technique for prenatal diagnosis of the fetal karyotype through cytogenetic analysis, and of Mendelian inherited diseases through molecular or biochemical analysis. Because the sampling technique can be performed in the first-trimester of pregnancy and diagnostic results can be obtained earlier than with amniocentesis, it has been utilized by clinicians in Europe and the US since 1982. CVS includes two methods: a transcervical approach and a transabdominal approach. Both are performed in the 10th week of pregnancy under careful ultrasound guidance to prevent adverse effects, but in comparison with amniocentesis, a slightly higher risk of pregnancy loss has been reported. Moreover, diagnostic accuracy is often disturbed by maternal cell contamination and chromosomal mosaicism of the placenta. Therefore, clinicians must give patients sufficient information on such technical and diagnostic trouble through counseling in order to obtain fully informed consent.
{"title":"Prenatal Genetic Diagnosis through Chorionic Villus Sampling","authors":"S. Uehara","doi":"10.1274/JMOR.21.13","DOIUrl":"https://doi.org/10.1274/JMOR.21.13","url":null,"abstract":"Chorionic villus sampling (CVS) is a technique for prenatal diagnosis of the fetal karyotype through cytogenetic analysis, and of Mendelian inherited diseases through molecular or biochemical analysis. Because the sampling technique can be performed in the first-trimester of pregnancy and diagnostic results can be obtained earlier than with amniocentesis, it has been utilized by clinicians in Europe and the US since 1982. CVS includes two methods: a transcervical approach and a transabdominal approach. Both are performed in the 10th week of pregnancy under careful ultrasound guidance to prevent adverse effects, but in comparison with amniocentesis, a slightly higher risk of pregnancy loss has been reported. Moreover, diagnostic accuracy is often disturbed by maternal cell contamination and chromosomal mosaicism of the placenta. Therefore, clinicians must give patients sufficient information on such technical and diagnostic trouble through counseling in order to obtain fully informed consent.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"188 1","pages":"13-17"},"PeriodicalIF":0.0,"publicationDate":"2004-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79446252","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}
-production(IVP) techniques in various formulations of media anddifferent culture conditions [1Œ5], but many technicalproblems still remain. For example, the cryotoleranceand rates of pregnancy of embryos produced by IVPtechniques were not high [6, 7]. Comparative studiesdemonstrated that the quality of bovine embryosproduced by IVP systems was lower than that of
{"title":"In Vitro Culture and Evaluation of Embryos for Production of High Quality Bovine Embryos","authors":"H. Abe, H. Shiku, S. Aoyagi, H. Hoshi","doi":"10.1274/JMOR.21.22","DOIUrl":"https://doi.org/10.1274/JMOR.21.22","url":null,"abstract":"-production(IVP) techniques in various formulations of media anddifferent culture conditions [1Œ5], but many technicalproblems still remain. For example, the cryotoleranceand rates of pregnancy of embryos produced by IVPtechniques were not high [6, 7]. Comparative studiesdemonstrated that the quality of bovine embryosproduced by IVP systems was lower than that of","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"22 1","pages":"22-30"},"PeriodicalIF":0.0,"publicationDate":"2004-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86318994","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}
Preimplantation genetic diagnosis (PGD) is a technology that allows for the selection and transfer of embryos unaffected by genetic disease. The limited number of cells available for genetic testing is a weakness of PGD and has been solved by means of the development of various strategies such as polymerase chain reaction (PCR), fluorescence in situ hybridization (FISH) and cell recycling. A confounding factor in PGD is the existence of preimplantation embryos with severe chromosomal abnormalities. Therefore, genetic analysis should be performed with the assumption that embryos have severe chromosomal abnormalities. The visualization of metaphase plates allows screening for numerical chromosomal abnormality and several kinds of structural chromosomal abnormality. In addition, in vitro culture of single isolated blastomeres makes it possible to reexamine samples to ensure accuracy of the results and to obtain additional genetic information.
{"title":"Preimplantation Genetic Diagnosis","authors":"Y. Sasabe, T. Nishimura, H. Kubo","doi":"10.1274/JMOR.21.2","DOIUrl":"https://doi.org/10.1274/JMOR.21.2","url":null,"abstract":"Preimplantation genetic diagnosis (PGD) is a technology that allows for the selection and transfer of embryos unaffected by genetic disease. The limited number of cells available for genetic testing is a weakness of PGD and has been solved by means of the development of various strategies such as polymerase chain reaction (PCR), fluorescence in situ hybridization (FISH) and cell recycling. A confounding factor in PGD is the existence of preimplantation embryos with severe chromosomal abnormalities. Therefore, genetic analysis should be performed with the assumption that embryos have severe chromosomal abnormalities. The visualization of metaphase plates allows screening for numerical chromosomal abnormality and several kinds of structural chromosomal abnormality. In addition, in vitro culture of single isolated blastomeres makes it possible to reexamine samples to ensure accuracy of the results and to obtain additional genetic information.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"58 1","pages":"2-6"},"PeriodicalIF":0.0,"publicationDate":"2004-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87152998","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}
The cryopreservation of supernumerary human blastocysts produced in vitro has been essential in assisted reproductive technology. In this case report, we report the clinical results of the transfer of expanded blastocysts that were cryopreserved by a slow-freezing method or a vitrification technique after artificial shrinkage. The post-thaw survival and re-expansion rates in the slow-freezing group (100 and 60%) were comparable with those in the vitrification group (95 and 95%). However, although no pregnancy was achieved in the slow-freezing group, high implantation and clinical pregnancy rates (44 and 60%) were achieved in the vitrification group.
{"title":"Cryopreservation of Human Blastocyst","authors":"K. Hiraoka, K. Hiraoka, M. Kinutani, K. Kinutani","doi":"10.1274/JMOR.21.65","DOIUrl":"https://doi.org/10.1274/JMOR.21.65","url":null,"abstract":"The cryopreservation of supernumerary human blastocysts produced in vitro has been essential in assisted reproductive technology. In this case report, we report the clinical results of the transfer of expanded blastocysts that were cryopreserved by a slow-freezing method or a vitrification technique after artificial shrinkage. The post-thaw survival and re-expansion rates in the slow-freezing group (100 and 60%) were comparable with those in the vitrification group (95 and 95%). However, although no pregnancy was achieved in the slow-freezing group, high implantation and clinical pregnancy rates (44 and 60%) were achieved in the vitrification group.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"8 1","pages":"65-68"},"PeriodicalIF":0.0,"publicationDate":"2004-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72971397","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":"IVM-IVF（未熟卵体外成熟体外受精胚移植法）の現況","authors":"愛作 福田","doi":"10.1274/JMOR.21.45","DOIUrl":"https://doi.org/10.1274/JMOR.21.45","url":null,"abstract":"","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"591 1","pages":"45-51"},"PeriodicalIF":0.0,"publicationDate":"2004-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74717249","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}
The effect of polyvinyl alcohol (PVA) on the development of mouse preimplantation embryos was examined. In Hoppe and Pitts medium supplemented with 0.1 or 1.0 mg/ml PVA, a high percentage (comparable to BSA-supplemented medium) of mouse 1-cell embryos developed to the expanded blastocyst stage. However, in medium supplemented with 10.0 mg/ml PVA, no embryos developed to the blastocyst stage. These results indicate that, at optimum concentration, PVA supports embryo development from the 1-cell to the expanded blastocyst stage, and that the PVA-supplemented medium is a valuable chemically defined medium for mouse embryonic culture. Also, in this study, in the PVA-supplemented medium, percentages and speeds of embryo development from each stage (1-cell, 2-cell, 8-cell and early blastocyst) to the expanded blastocyst stage were almost the same as those in the BSA-supplemented medium. These results suggest that these embryos developed to expanded blastocysts via normal processes, and that PVA supports embryo development in each stage up to the expanded blastocyst stage. Incidence of partial hatching and complete hatching of blastocysts was clearly decreased in cultures of each embryo from 1-cell to the early blastocyst stage in the PVA-supplemented medium. It has been considered that protease may participate in the hatching process of blastocysts in vitro, thus, it is probable that the low hatching rate of blastocysts in the PVA-supplemented medium is due to a decline in protease synthesis and/or secretion.
{"title":"Efficacy of Polyvinyl Alcohol Supporting the Development of Mouse Preimplantation Embryo In Vitro","authors":"F. Koyanagi, S. Masuda","doi":"10.1274/JMOR.21.31","DOIUrl":"https://doi.org/10.1274/JMOR.21.31","url":null,"abstract":"The effect of polyvinyl alcohol (PVA) on the development of mouse preimplantation embryos was examined. In Hoppe and Pitts medium supplemented with 0.1 or 1.0 mg/ml PVA, a high percentage (comparable to BSA-supplemented medium) of mouse 1-cell embryos developed to the expanded blastocyst stage. However, in medium supplemented with 10.0 mg/ml PVA, no embryos developed to the blastocyst stage. These results indicate that, at optimum concentration, PVA supports embryo development from the 1-cell to the expanded blastocyst stage, and that the PVA-supplemented medium is a valuable chemically defined medium for mouse embryonic culture. Also, in this study, in the PVA-supplemented medium, percentages and speeds of embryo development from each stage (1-cell, 2-cell, 8-cell and early blastocyst) to the expanded blastocyst stage were almost the same as those in the BSA-supplemented medium. These results suggest that these embryos developed to expanded blastocysts via normal processes, and that PVA supports embryo development in each stage up to the expanded blastocyst stage. Incidence of partial hatching and complete hatching of blastocysts was clearly decreased in cultures of each embryo from 1-cell to the early blastocyst stage in the PVA-supplemented medium. It has been considered that protease may participate in the hatching process of blastocysts in vitro, thus, it is probable that the low hatching rate of blastocysts in the PVA-supplemented medium is due to a decline in protease synthesis and/or secretion.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"56 1","pages":"31-35"},"PeriodicalIF":0.0,"publicationDate":"2004-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90433707","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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