{"title":"In Vitro Production of Blastocyst and Embryo Transfer in Mammals","authors":"K. Takagishi, Kenji Momozawa, Y. Fukuda","doi":"10.1274/JMOR.20.2","DOIUrl":"https://doi.org/10.1274/JMOR.20.2","url":null,"abstract":"","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"1 1","pages":"2-6"},"PeriodicalIF":0.0,"publicationDate":"2003-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87732948","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}
Y. Sasabe, T. Nishimura, Kanako Hanaoka, Hikoyoshi Jinnai, Y. Shibui, Y. Katagiri, K. Masaki, Y. Abe, H. Kubo
Cleavage-stage embryos have been transferred to the uterus since the first successful in vitro fertilization-embryo transfer (IVF-ET). Physiologically the embryos transferred to the uterus should be at the blastocyst stage, but cultivation to the blastocyst stage was difficult because of a poor culture environment. At the first attempt reported by Bolton et al. in 1989 [1] and 1991 [2] only 17% of embryos reached the expanded blastocyst stage and the implantation rate for blastocyst transfer (BT) was 7%. Subsequently, Menezo et al. [3] introduced a coculture system with Vero cells, with which 55(cid:150)60% of embryos reached the blastocyst stage. With the sequential medium, it is now possible to culture embryos to the blastocyst stage without feeder cells [4]. Gardner et al. [5] reported that the proportion of embryos reaching the blastocyst stage was 46.5% and the implantation rate for BT was 50.5%. Furthermore, their comparison study with conventional embryo transfer at the cleavage stage (ET) showed that the implantation rate for BT was much higher than that for ET [5].
{"title":"Blastocyst Transfer: Means of Overcoming Disadvantages Focused on Embryo Selection","authors":"Y. Sasabe, T. Nishimura, Kanako Hanaoka, Hikoyoshi Jinnai, Y. Shibui, Y. Katagiri, K. Masaki, Y. Abe, H. Kubo","doi":"10.1274/JMOR.20.25","DOIUrl":"https://doi.org/10.1274/JMOR.20.25","url":null,"abstract":"Cleavage-stage embryos have been transferred to the uterus since the first successful in vitro fertilization-embryo transfer (IVF-ET). Physiologically the embryos transferred to the uterus should be at the blastocyst stage, but cultivation to the blastocyst stage was difficult because of a poor culture environment. At the first attempt reported by Bolton et al. in 1989 [1] and 1991 [2] only 17% of embryos reached the expanded blastocyst stage and the implantation rate for blastocyst transfer (BT) was 7%. Subsequently, Menezo et al. [3] introduced a coculture system with Vero cells, with which 55(cid:150)60% of embryos reached the blastocyst stage. With the sequential medium, it is now possible to culture embryos to the blastocyst stage without feeder cells [4]. Gardner et al. [5] reported that the proportion of embryos reaching the blastocyst stage was 46.5% and the implantation rate for BT was 50.5%. Furthermore, their comparison study with conventional embryo transfer at the cleavage stage (ET) showed that the implantation rate for BT was much higher than that for ET [5].","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"29 1","pages":"25-28"},"PeriodicalIF":0.0,"publicationDate":"2003-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87425072","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. Shibahara, H. Obara, Kumiko Kikuchi, Seiji Yamanaka, Y. Hirano, Tatsuya Suzuki, S. Takamizawa, Mitsuaki Suzuki
Human sperm cannot fertilize oocytes immediately upon ejaculation, but must acquire the ability to bind and penetrate the zona pellucida. Hyperactivation, which is linked to the process of capacitation, is a vigorous pattern of sperm motility marked by wide-amplitude, high-velocity, whiplash movements of the flagellum. This study was performed to investigate the correlation between hyperactivated (HA) motility patterns assessed by computer-aided sperm analysis (CASA) and the fertilization rate (FR) in vitro. Swim-up sperm were collected in 135 IVF cycles with at least 3 oocytes collected. Because no cases satisfied the HA motility pattern of "Star-spin", patients were divided into 3 groups: Sperm with curvilinear velocity (VCL) ≥ 100 μM/sec, linearity (LIN) < 60% and amplitude of lateral head displacement (ALH) ≥ 5 μM were "All HA". Sperm with straight-line velocity (VSL) ≥ 40 μM/sec, LIN ≥ 60% and ALH < 5 μM were "Non-HA". Others were defined as "Transition phase". The FRs in 81 "All HA" cycles, 33 "Non-HA" cycles, and 21 "Transition phase" cycles were 79.5 ± 26.6%, 65.4 ± 32.5%, and 80.8 ± 27.3% respectively. There was a significant difference between "All HA" and "Non-HA" cycles in the FRs (P=0.018). In 27 (20.0%) of 135 IVF cycles, the FRs were ≤ 50% ("poor" group). Eleven (13.6%) of 81 "All HA" cycles, 12 (36.3%) of 33 "Non-HA" cycles, and 4 of 21 "Transition phase" cycles belonged to the "poor" group. There was a significant difference between "All HA" and "Non-HA" cycles (P=0.006) in these incidences. The better FRs were obtained in patients with "All HA" cycles, and lower FRs were obtained in those with "Non-HA" cycles. These findings suggest that the assessment of HA motility patterns by means of CASA could be one of the predictors of human sperm fertilizing ability.
{"title":"Prediction of Human Sperm Fertilizing Ability by the Hyperactivated Motility Patterns","authors":"H. Shibahara, H. Obara, Kumiko Kikuchi, Seiji Yamanaka, Y. Hirano, Tatsuya Suzuki, S. Takamizawa, Mitsuaki Suzuki","doi":"10.1274/JMOR.20.29","DOIUrl":"https://doi.org/10.1274/JMOR.20.29","url":null,"abstract":"Human sperm cannot fertilize oocytes immediately upon ejaculation, but must acquire the ability to bind and penetrate the zona pellucida. Hyperactivation, which is linked to the process of capacitation, is a vigorous pattern of sperm motility marked by wide-amplitude, high-velocity, whiplash movements of the flagellum. This study was performed to investigate the correlation between hyperactivated (HA) motility patterns assessed by computer-aided sperm analysis (CASA) and the fertilization rate (FR) in vitro. Swim-up sperm were collected in 135 IVF cycles with at least 3 oocytes collected. Because no cases satisfied the HA motility pattern of \"Star-spin\", patients were divided into 3 groups: Sperm with curvilinear velocity (VCL) ≥ 100 μM/sec, linearity (LIN) < 60% and amplitude of lateral head displacement (ALH) ≥ 5 μM were \"All HA\". Sperm with straight-line velocity (VSL) ≥ 40 μM/sec, LIN ≥ 60% and ALH < 5 μM were \"Non-HA\". Others were defined as \"Transition phase\". The FRs in 81 \"All HA\" cycles, 33 \"Non-HA\" cycles, and 21 \"Transition phase\" cycles were 79.5 ± 26.6%, 65.4 ± 32.5%, and 80.8 ± 27.3% respectively. There was a significant difference between \"All HA\" and \"Non-HA\" cycles in the FRs (P=0.018). In 27 (20.0%) of 135 IVF cycles, the FRs were ≤ 50% (\"poor\" group). Eleven (13.6%) of 81 \"All HA\" cycles, 12 (36.3%) of 33 \"Non-HA\" cycles, and 4 of 21 \"Transition phase\" cycles belonged to the \"poor\" group. There was a significant difference between \"All HA\" and \"Non-HA\" cycles (P=0.006) in these incidences. The better FRs were obtained in patients with \"All HA\" cycles, and lower FRs were obtained in those with \"Non-HA\" cycles. These findings suggest that the assessment of HA motility patterns by means of CASA could be one of the predictors of human sperm fertilizing ability.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"14 3 1","pages":"29-33"},"PeriodicalIF":0.0,"publicationDate":"2003-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78404303","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 recent advance of many technologies in assisted reproduction in experimental and domestic animals has been remarkable. Boerjan et al. [1] described that Assisted Reproductive Technologies (ART) have been introduced 1) to overcome reproductive failures in the humans, 2) to increase the number of offspring from selected females and 3) to reduce generation intervals in l ivestock. However, many technical problems remain, for example, the rates of implantation and p regnancy o f em bryos p roduced by ass i s ted reproductive technologies are not high in cattle [2] and humans [3]. Assurance of cytogenetic quality of the embryos is essential to get higher conception rates. Especially, cytogenetic normality is a very important issue in respect of generation effects in humans. Many reports concerning chromosomal abnormalities have been published [410], and some of them have made ment ion of the re la t ion between chromosomal abnormalities and the maturity of oocytes and sperm concentration, however the evaluation of cytogenetic safety in ART is insufficient. It has been shown that chromosome analysis of spare human embryos may have a predictive value for their transferred sibling embryos, and detection of chromosomally normal embryos for transfer is integral for improving the success rate in human In Vitro Fertilization (IVF) [11]. The present review looks at the incidences of chromosomal abnormalities in embryos of several
{"title":"Chromosomal Abnormalities and Embryonic Development into the Blastocyst Stage in Mammalian Embryos Derived In Vitro","authors":"M. Yoshizawa","doi":"10.1274/JMOR.20.7","DOIUrl":"https://doi.org/10.1274/JMOR.20.7","url":null,"abstract":"The recent advance of many technologies in assisted reproduction in experimental and domestic animals has been remarkable. Boerjan et al. [1] described that Assisted Reproductive Technologies (ART) have been introduced 1) to overcome reproductive failures in the humans, 2) to increase the number of offspring from selected females and 3) to reduce generation intervals in l ivestock. However, many technical problems remain, for example, the rates of implantation and p regnancy o f em bryos p roduced by ass i s ted reproductive technologies are not high in cattle [2] and humans [3]. Assurance of cytogenetic quality of the embryos is essential to get higher conception rates. Especially, cytogenetic normality is a very important issue in respect of generation effects in humans. Many reports concerning chromosomal abnormalities have been published [410], and some of them have made ment ion of the re la t ion between chromosomal abnormalities and the maturity of oocytes and sperm concentration, however the evaluation of cytogenetic safety in ART is insufficient. It has been shown that chromosome analysis of spare human embryos may have a predictive value for their transferred sibling embryos, and detection of chromosomally normal embryos for transfer is integral for improving the success rate in human In Vitro Fertilization (IVF) [11]. The present review looks at the incidences of chromosomal abnormalities in embryos of several","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"45 1","pages":"7-15"},"PeriodicalIF":0.0,"publicationDate":"2003-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87722260","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 vitro fertilization-embryo transfer (IVF-ET) is not yet one of the most effective treatment for infertile couples.
体外受精-胚胎移植(IVF-ET)还不是最有效的治疗不孕夫妇之一。
{"title":"Blastocyst Transfer - Its Efficacy and Problems","authors":"N. Takeshita, Y. Abe, H. Kubo","doi":"10.1274/JMOR.20.16","DOIUrl":"https://doi.org/10.1274/JMOR.20.16","url":null,"abstract":"In vitro fertilization-embryo transfer (IVF-ET) is not yet one of the most effective treatment for infertile couples.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"82 1","pages":"16-19"},"PeriodicalIF":0.0,"publicationDate":"2003-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88101924","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":"免疫染色法によるDNA 5-メチルシトシンの検出","authors":"弥咲 須永, 浩孝 木村, Che Li mei, 雅夫 伊藤, 友宏 河野","doi":"10.1274/JMOR.20.55","DOIUrl":"https://doi.org/10.1274/JMOR.20.55","url":null,"abstract":"","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"3 1","pages":"55-57"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84793738","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 activities of hydroxysteroid dehydrogenases (HSDs) were histochemically demonstrated in rabbit and hamster oocytes in the process of maturation, and the changes in steroid metabolism during meiotic maturation were examined. In rabbits, the percentages of oocytes showing the activities of Δ5-3β-HSD (with DHEA as the substrate), 17β-HSD (testosterone) and 20β-HSD (20β-hydroxyprogesterone) were always high and did not change during maturation, whereas those showing the activities of Δ5-3β-HSD (pregnenolone and 17α-hydroxy-pregnenolone), 17 β-HSD (estradiol-17β), 20α-HSD (20 α-hydroxyprogesterone) and 20β-HSD (17α-hydroxyprogesterone) decreased as the time after the hCG injection was prolonged. On the other hand, the activities of Δ5-3β-HSD, 17 β-HSD, 20α-HSD and 20β-HSD with eight substrates were almost always observed in hamster oocytes from 0 to 13 hrs after the hCG injection. The present findings suggested that the metabolic abilities of 20β-hydroxyprogesterone and androgen are constantly present in rabbit oocytes in the process of maturation, whereas those of progesterone, 17α-hydroxyprogesterone, 17α, 20β-dihydroxyprogesterone, 20α-hydroxyprogesterone and estrogen decrease during maturation. And it was also confirmed in hamster oocytes that the metabolic abilities of progesterone, 17α-hydroxyprogesterone, 17α, 20β-dihydroxyprogesterone, 20α-hydroxyprogesterone, 20β-hydroxyprogesterone, estrogen and androgen are always present and do not vary with maturation.
{"title":"Changes in the Activities of Hydroxysteroid Dehydrogenases in Rabbit and Hamster Oocytes during Meiotic Maturation","authors":"S. Niimura, S. Kawakami","doi":"10.1274/JMOR.20.118","DOIUrl":"https://doi.org/10.1274/JMOR.20.118","url":null,"abstract":"The activities of hydroxysteroid dehydrogenases (HSDs) were histochemically demonstrated in rabbit and hamster oocytes in the process of maturation, and the changes in steroid metabolism during meiotic maturation were examined. In rabbits, the percentages of oocytes showing the activities of Δ5-3β-HSD (with DHEA as the substrate), 17β-HSD (testosterone) and 20β-HSD (20β-hydroxyprogesterone) were always high and did not change during maturation, whereas those showing the activities of Δ5-3β-HSD (pregnenolone and 17α-hydroxy-pregnenolone), 17 β-HSD (estradiol-17β), 20α-HSD (20 α-hydroxyprogesterone) and 20β-HSD (17α-hydroxyprogesterone) decreased as the time after the hCG injection was prolonged. On the other hand, the activities of Δ5-3β-HSD, 17 β-HSD, 20α-HSD and 20β-HSD with eight substrates were almost always observed in hamster oocytes from 0 to 13 hrs after the hCG injection. The present findings suggested that the metabolic abilities of 20β-hydroxyprogesterone and androgen are constantly present in rabbit oocytes in the process of maturation, whereas those of progesterone, 17α-hydroxyprogesterone, 17α, 20β-dihydroxyprogesterone, 20α-hydroxyprogesterone and estrogen decrease during maturation. And it was also confirmed in hamster oocytes that the metabolic abilities of progesterone, 17α-hydroxyprogesterone, 17α, 20β-dihydroxyprogesterone, 20α-hydroxyprogesterone, 20β-hydroxyprogesterone, estrogen and androgen are always present and do not vary with maturation.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"12 1","pages":"118-123"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80702215","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}
N. Sugawara, K. Yanagida, M. Maeda, Nobuaki Suzuki, Y. Tokunaga, A. Sato
Conjoined twins result from an abnormal process in the development of monozygotic twins. Monozygotic twins are closely associated with assisted reproductive technology, especially assisted hatching. The prognosis for conjoined twins is very poor. This risk underscores the importance of fetal screening by ultrasonography in the early stages of pregnancy, since the conjoined twin can be detected by ultrasonography. Here we reported a case of conjoined twin in a triplet pregnancy after a transfer of cryopreserved embryos with assisted hatching that were obtained by ICSI.
{"title":"Conjoined Twin in Triplet Pregnancy Occurring after ICSI, Cryopreservation, and Assisted Hatching","authors":"N. Sugawara, K. Yanagida, M. Maeda, Nobuaki Suzuki, Y. Tokunaga, A. Sato","doi":"10.1274/JMOR.20.41","DOIUrl":"https://doi.org/10.1274/JMOR.20.41","url":null,"abstract":"Conjoined twins result from an abnormal process in the development of monozygotic twins. Monozygotic twins are closely associated with assisted reproductive technology, especially assisted hatching. The prognosis for conjoined twins is very poor. This risk underscores the importance of fetal screening by ultrasonography in the early stages of pregnancy, since the conjoined twin can be detected by ultrasonography. Here we reported a case of conjoined twin in a triplet pregnancy after a transfer of cryopreserved embryos with assisted hatching that were obtained by ICSI.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"54 1","pages":"41-44"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75645827","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}
Y. Hosoi, R. Torii, N. Fujinami, Kazuya Matsumoto, K. Saeki, A. Iritani
Intracytoplasmic Sperm Injection (ICSI) has been widely applied for curing human infertility. In this study the developmental potential of Japanese monkey embryos produced by ICSI is reported in a practically relevant system. Oocytes retrieved by laparoscopy from follicles in ovaries of gonadotrophin-stimulated fertile females were fertilized by ICSI using spermatozoa obtained from a fertile male. An additional chemical stimulus was not necessary to achieve oocyte activation with pronuclear formation after ICSI. Successful fertilization was confirmed by extrusion of the second polar body and the presence of both male and female pronuclei at 18-20 h post-ICSI. Some two-cell stage embryos obtained by ICSI were transferred to synchronous recipients and the others were cultured in CMRL medium for 168 h to assess their developmental competence. Oocytes collected laparoscopically from hyper-stimulated monkey ovaries were fertilized by ICSI and completed preimplantation development in vitro, however no pregnancy was confirmed after embryo transfer. This study demonstrates for the first time that the oocytes of the Japanese monkey are able to support advanced embryonic preimplantation development in vitro. It is suggested that the Japanese monkey is an excellent preclinical model for examining and understanding many aspects of ICSI for endangered primates.
{"title":"Fertilization by Intracytoplasmic Sperm Injection and Subsequent Embryo Development In Vitro to Blastocysts in Japanese Monkey (Macaca fuscata)","authors":"Y. Hosoi, R. Torii, N. Fujinami, Kazuya Matsumoto, K. Saeki, A. Iritani","doi":"10.1274/JMOR.20.34","DOIUrl":"https://doi.org/10.1274/JMOR.20.34","url":null,"abstract":"Intracytoplasmic Sperm Injection (ICSI) has been widely applied for curing human infertility. In this study the developmental potential of Japanese monkey embryos produced by ICSI is reported in a practically relevant system. Oocytes retrieved by laparoscopy from follicles in ovaries of gonadotrophin-stimulated fertile females were fertilized by ICSI using spermatozoa obtained from a fertile male. An additional chemical stimulus was not necessary to achieve oocyte activation with pronuclear formation after ICSI. Successful fertilization was confirmed by extrusion of the second polar body and the presence of both male and female pronuclei at 18-20 h post-ICSI. Some two-cell stage embryos obtained by ICSI were transferred to synchronous recipients and the others were cultured in CMRL medium for 168 h to assess their developmental competence. Oocytes collected laparoscopically from hyper-stimulated monkey ovaries were fertilized by ICSI and completed preimplantation development in vitro, however no pregnancy was confirmed after embryo transfer. This study demonstrates for the first time that the oocytes of the Japanese monkey are able to support advanced embryonic preimplantation development in vitro. It is suggested that the Japanese monkey is an excellent preclinical model for examining and understanding many aspects of ICSI for endangered primates.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"15 1","pages":"34-40"},"PeriodicalIF":0.0,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89373730","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 number of cells and the rate of cell division were observed in diploid parthenogenetic mouse embryos during the course of blastocyst formation, and were compared with those in embryos developed from fertilized ova (fertilized embryos), in order to identify the stage at which the number of cells begins to differ and the cause of difference in cell number between parthenogenetic and fertilized embryos. The number of cells and the rate of cell division did not differ between parthenogenetic and fertilized embryos at the 8-cell and compacted morula stages. The numbers of inner-cell-mass and trophoblast cells did not differ between parthenogenetic and fertilized embryos at the early blastocyst stage, but were significantly fewer in parthenogenetic embryos (11.1 and 32.7) than in fertilized embryos (14.9 and 52.0) at the expanded blastocyst stage. The numbers of dead inner-cell-mass and trophoblast cells were significantly more in parthenogenetic embryos than in fertilized ones at the early and expanded blastocyst stages. At the early blastocyst stage, although no difference was observed between parthenogenetic and fertilized embryos in the rate of division of trophoblast cells, the rate of division of inner-cell-mass cells was significantly lower in parthenogenetic embryos (4.4%) than in fertilized ones (9.7%). There was no difference in the rate of cell division between parthenogenetic and fertilized embryos at the expanded blastocyst stage. From these results, it was inferred that the number of cells in diploid parthenogenetic embryos does not differ from fertilized embryos until blastocyst formation, but becomes fewer than in fertilized embryos because more cells are dying in parthenogenetic embryos during the expansion of blastocysts. A low rate of cell division in the early blastocyst stage is thought to be one reason for the fewer number of inner-cell-mass cells in parthenogenetic embryos at the expanded stage, in addition to the presence of a large number of dead cells.
{"title":"The Number of Cells and the Rate of Cell Division in Parthenogenetic and Fertilized Mouse Embryos during the Course of Blastocyst Formation","authors":"S. Niimura, Yukino Nakamura, K. Yoshino","doi":"10.1274/JMOR.19.66","DOIUrl":"https://doi.org/10.1274/JMOR.19.66","url":null,"abstract":"The number of cells and the rate of cell division were observed in diploid parthenogenetic mouse embryos during the course of blastocyst formation, and were compared with those in embryos developed from fertilized ova (fertilized embryos), in order to identify the stage at which the number of cells begins to differ and the cause of difference in cell number between parthenogenetic and fertilized embryos. The number of cells and the rate of cell division did not differ between parthenogenetic and fertilized embryos at the 8-cell and compacted morula stages. The numbers of inner-cell-mass and trophoblast cells did not differ between parthenogenetic and fertilized embryos at the early blastocyst stage, but were significantly fewer in parthenogenetic embryos (11.1 and 32.7) than in fertilized embryos (14.9 and 52.0) at the expanded blastocyst stage. The numbers of dead inner-cell-mass and trophoblast cells were significantly more in parthenogenetic embryos than in fertilized ones at the early and expanded blastocyst stages. At the early blastocyst stage, although no difference was observed between parthenogenetic and fertilized embryos in the rate of division of trophoblast cells, the rate of division of inner-cell-mass cells was significantly lower in parthenogenetic embryos (4.4%) than in fertilized ones (9.7%). There was no difference in the rate of cell division between parthenogenetic and fertilized embryos at the expanded blastocyst stage. From these results, it was inferred that the number of cells in diploid parthenogenetic embryos does not differ from fertilized embryos until blastocyst formation, but becomes fewer than in fertilized embryos because more cells are dying in parthenogenetic embryos during the expansion of blastocysts. A low rate of cell division in the early blastocyst stage is thought to be one reason for the fewer number of inner-cell-mass cells in parthenogenetic embryos at the expanded stage, in addition to the presence of a large number of dead cells.","PeriodicalId":90599,"journal":{"name":"Journal of mammalian ova research","volume":"253 1","pages":"66-70"},"PeriodicalIF":0.0,"publicationDate":"2002-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78377326","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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