The current status and importance of preserving fish germplasm resources were described. The basic principle of cryobiology and its application potentials in preservation of aquatic germplasm resources were examined. ...The current status and importance of preserving fish germplasm resources were described. The basic principle of cryobiology and its application potentials in preservation of aquatic germplasm resources were examined. The mechanism of cryodamage was discussed. The recent advances and major problems in finfish gamete and embryo cryopreservation were reviewed. The prospects for cryopreservation research in fish gametes and embryos were looked into. The important research directions in cryopreservation of aquatic organisms were proposed.展开更多
Several extrinsic signals such as LIF, BMP and Wnt can support the self-renewal and pluripotency of embryonic stem （ES） cells through regulating the ＂pluripotent genes.＂ A unique homeobox transcription factor, Nan...Several extrinsic signals such as LIF, BMP and Wnt can support the self-renewal and pluripotency of embryonic stem （ES） cells through regulating the ＂pluripotent genes.＂ A unique homeobox transcription factor, Nanog, is one of the key downstream effectors of these signals. Elevated level of Nanog can maintain the mouse ES cell self-renewal independent of LIF and enable human ES cell growth without feeder cells. In addition to the external signal pathways, intrinsic transcription factors such as FoxD3, P53 and Oct4 are also involved in regulating the expression of Nanog. Functionally, Nanog works together with other key pluripotent factors such as Oct4 and Sox2 to control a set of target genes that have important functions in ES cell pluripotency. These key factors form a regulatory network to support or limit each other＇s expression level, which maintains the properties of ES cells.展开更多
文摘The current status and importance of preserving fish germplasm resources were described. The basic principle of cryobiology and its application potentials in preservation of aquatic germplasm resources were examined. The mechanism of cryodamage was discussed. The recent advances and major problems in finfish gamete and embryo cryopreservation were reviewed. The prospects for cryopreservation research in fish gametes and embryos were looked into. The important research directions in cryopreservation of aquatic organisms were proposed.
文摘Several extrinsic signals such as LIF, BMP and Wnt can support the self-renewal and pluripotency of embryonic stem （ES） cells through regulating the ＂pluripotent genes.＂ A unique homeobox transcription factor, Nanog, is one of the key downstream effectors of these signals. Elevated level of Nanog can maintain the mouse ES cell self-renewal independent of LIF and enable human ES cell growth without feeder cells. In addition to the external signal pathways, intrinsic transcription factors such as FoxD3, P53 and Oct4 are also involved in regulating the expression of Nanog. Functionally, Nanog works together with other key pluripotent factors such as Oct4 and Sox2 to control a set of target genes that have important functions in ES cell pluripotency. These key factors form a regulatory network to support or limit each other＇s expression level, which maintains the properties of ES cells.
