خيارات البحث
النتائج 1 - 8 من 8
Effects of various cryoprotectants on the survival of mouse embryos cryopreserved by the quick freezing method
1989
Mazni, O.A. (Yokohama Univ. (Japan). Faculty of Engineering) | Takahashi, Y. | Valdez, C.A. | Nishinuma, M. | Kanagawa, H.
Histochemical observations of lipid droplets in mouse embryos
1985
Hishinuma, M. (Hokkaido Univ., Sapporo (Japan). Faculty of Veterinary Medicine) | Takahashi, Y. | Kanagawa, H.
Inductions of superovulation using several FSH regimens in Holstein-Friesian heifers
1985
Takahashi, Y. (Hokkaido Univ., Sapporo (Japan). Faculty of Veterinary Medicine) | Kanagawa, H.
Feasibility of cryopreservation of zebrafish (Danio rerio) primordial germ cells by whole embryo freezing
2009
Higaki, S.(Hokkaido Univ., Sapporo (Japan)) | Mochizuki, K. | Baba, H. | Akashi, Y. | Yamaha, E. | Katagiri, S. | Takahashi, Y.
We investigated the feasibility of cryopreservation of zebrafish (Danio rerio) blastomeres and primordial germ cells (PGCs) by rapid freezing of dechorionated whole embryos at the blastula, gastrula and segmentation stages. Initially we examined the glass-forming properties and embryo toxicities of 5 cryoprotectants: methanol (MeOH), ethylene glycol (EG), dimethyl sulfoxide (DMSO), propylene glycol (PG), and 1,3-butylene glycol (1,3-BG). Embryos at the blastula and gastrula stages had high sensitivities to cryoprotectant toxicities and were fragile against mechanical damage. Thus the segmentation stage embryos, the PGCs of which were visualized by injecting green fluorescence protein-nos1 3'UTR mRNA, were frozen using solutions containing each cryoprotectant at 6 M (first trial) and 2 types of cryoprotectants at 3 M each (second trial). In the first trial, live PGCs were recovered from most of the embryos frozen with EG (about 2 cells/embryo); however, a few embryos had live PGCs when embryos were frozen with other cryoprotectants. In the second trial; a mixture of EG + PG better preserved the viability of PGCs in frozen embryos. Live PGCs were recovered from all embryos frozen with EG + PG (about 3 cells/embryo), and the survival rate of PGCs was estimated to be about 25% based on the number of live PGCs in fresh embryos (about 12 cells/embryo). The present study indicates that we can utilize rapid freezing of dechorionated whole embryos at the segmentation stage for the cryopreservation of PGCs.
اظهر المزيد [+] اقل [-]Examination of the Lunatic fringe and Uncx4.1 expression by whole-mount in situ hybridization in the embryo of the CKH-Jsr (jumbled spine and ribs) mouse
2005
Okano, S. (Hokkaido Univ., Sapporo (Japan)) | Asano, A. | Sasaki, N. | Kon, Y. | Watanabe, T. | Agui, T.
The CKH-Jsr (jumbled spine and ribs) mouse was found as a spontaneous mutant with malformation of vertebrae, that is, a short trunk and kinky tail. We examined Lunatic Fringe (Lfng and Uncx4. 1 expression in the presomitic mesoderm (PSM) and somites of Jsr-mutant (CKH-Jsr/+) embryos to elucidate pathogenesis of the Jsr mutation. Expression pattern of Lfng in the PSM of Jsr-mutant embryos was similar to that of the normal (C57BL/6) embryos. However, expression pattern of Uncx4. 1 in the somites of Jsr-mutant embryos was impaired to be irregular and mosaic, suggesting that the anterior-posterior (A-P) polarity is disordered in the Jsr mutant. These results indicate that the Jsr mutation disrupts the A-P polarity of somites during the somitogenesis without altering Lfng expression pattern in the PSM.
اظهر المزيد [+] اقل [-]Effects of oxygen tension in the gas atmosphere during in vitro maturation, in vitro fertilization and in vitro culture on the efficiency of in vitro production of mouse embryos
2004
Adam, A.A.G. (Hokkaido Univ., Sapporo (Japan)) | Takahashi, Y. | Katagiri, S. | Nagano, M.
Effects of oxygen (O2) tension in the gas atmosphere during in vitro maturation (IVM), in vitro fertilization (IVF) and in vitro culture (IVC) on the efficiency of in vitro production of mouse embryos were examined. Mouse oocytes recovered from large antral follicles were subjected to IVM in Waymouth medium for 15, 16 and 17 hr under 5 or 20% O2 and then subjected to IVF and IVC under 5 or 20% O2 tension. Lowering the O2 tension in the gas atmosphere for IVM from 20 to 5% improved the cleavage rate after IVF when the oocytes were subjected to IVM for 15 hr; however, no improvement in the cleavage rate was observed when the culture period for IVM was extended to 16 and 17 hr. Lowering the O2 tension to 5% for IVM and IVC improved the development of the cleaved oocytes to the blastocyst stage, regardless of the culture period for IVM. However, the O2 tension for IVF had no remarkable effect on the subsequent embryonic development. These results demonstrate that 5% O2 is superior to 20% O2 for IVM and IVC, and suggest that 20% O2 for IVM may delay oocyte maturation and/or the acquisition of fertilizability and impair the developmental competence of oocytes.
اظهر المزيد [+] اقل [-]Differentiative potential of a mouse parthenogenetic embryonic stem cell line revealed by embryoid body formation in vitro
1998
Park, J.I. (Hokkaido Univ., Sapporo (Japan)) | Yoshida, I. | Tada, T. | Takagi, N. | Takahashi, Y. | Kanagawa, H.
The in vitro differentiative potential of mouse parthenogenetic (PG) embryonic stem (PGES) cells were investigated in the formation of embryoid bodies (EBs). EBs derived from PGES cells retarded in growth and showed restricted differentiation compared to their fertilized counterpart. In chimeric EBs from the aggregation of PGES and fertilized ES cells, morphological examination revealed that PGES cells were reduced in their population and distributed in endodermal layer as culture periods proceeded. These findings were comparable to those in aggregation chimeras of fertilized and PG embryos, and suggest that the differentiation of PGES cells in vitro is restricted in the formation of EBs
اظهر المزيد [+] اقل [-]The effectiveness of trysin treatment to remove Sendai virus adhering to the zona pellucida of mouse preimplantation embryos
1991
Lavilla-Apelo, C. (Hokkaido Univ., Sapporo (Japan). Faculty of Veterinary Medicine) | Kida, H. | Kanagawa, H.