The region between the preexisting and nascent membranes of a cleaving Rana egg is a dense protrusion region of nearly 40μm wide at 180° stage.Later,this region differentiate,into an upper part,a strip with lon...The region between the preexisting and nascent membranes of a cleaving Rana egg is a dense protrusion region of nearly 40μm wide at 180° stage.Later,this region differentiate,into an upper part,a strip with long,branched and randomly distributed protrusions which are derived largely from the preexisting membrane and a lower part,a band with microvilli.During 4-and 8-cell stages,the strip is almost vanished and microvilli in the band is shortened.The nascent membrane is smooth at the 180° stage,then a rough area appears below the smooth region and quickly expands,wheat germ agglutini which can bind to preexisting membrane interrupts the development of the region between the preexisting and nascent membranes Detergent,Brij,having the property to increase the area of nascent membrane,does not interupt the development of the region between the preexisting and nascent membranes.展开更多
By laser scanning fluorescence microscopy for quan-titative measurement of fluorescence intensity changes on egg surface stained with fluorescein isothiocyanate duxing cleavage furrow extending forward, it was found t...By laser scanning fluorescence microscopy for quan-titative measurement of fluorescence intensity changes on egg surface stained with fluorescein isothiocyanate duxing cleavage furrow extending forward, it was found that in area of presumptive cleavage furrow the scanning curve became ∨ shape, indicating dark stripe appeared in that place. Then the fluorescence intensity increased at the place where the botton of ∨ shape had located, and the scanning curve tuxned to ∧ shape, indicating single stripe was formed. While enhanced fluorescence appeared on the borders of ∧ shape, an M shape curve was found, show-ing double stripe occurred. During the distance between two borders of M shape incresing from 50 μm to 100μm,a fluorescence peak came to sight in the middle of the M shape, which being the cleavge furrow bottom. The two lateral sides of furrow bottom with decreasing fluorescence were nascent membrane. At that time the curve became W shape. By the sides of cleavage furrow the the stress folds became conspicous after double stripe stage, showing the stretching of the egg surface being increased. With our[31, 33] and others[32] reports that polylysine could induce the appearance of nascent membrane and phyto-hemagglutinins could decrease or prevent the appearance of nascent membrane, we believed the idea of Schroeder[25] that increasing mechanical stress could initiate nascent membrane formation and thought that the stress lay to the outsides of cleavage furrow.展开更多
Cell couplings before and after neural induction in embryos of Cynops orientalis were studied by means of single cell injection of Lucifer Yellow.Differences both in incidence and the extent of cell couplings were dem...Cell couplings before and after neural induction in embryos of Cynops orientalis were studied by means of single cell injection of Lucifer Yellow.Differences both in incidence and the extent of cell couplings were demonstrated.Results of cell couplings were correlated with electron microscopic observations of freeze-etching replicas.展开更多
文摘旨在研究IGF s及其受体(IGFR)在绵羊卵母细胞和早期胚胎中的表达.对绵羊进行超数排卵处理,手术法采卵得到卵母细胞和着床前早期胚胎,结合荧光免疫染色方法和激光共聚焦成像系统,研究了绵羊未成熟卵母细胞、成熟卵母细胞和着床前各期胚胎中IGF-I、IGF-II、IGF-IR、IGF-IIR的表达情况.结果表明,IGF-I、IGF-II在未成熟卵母细胞和成熟卵母细胞中均有表达;受精后,直到囊胚的整个早期发育阶段也检测到了这两个因子的表达,且胚胎免疫染色在各卵裂球之间呈现不均匀的分布.IGF-IR和IGF-IIR在未成熟卵母细胞、成熟卵母细胞和早期胚胎均有表达,在胚胎期主要分布于卵裂球细胞的顶端(ap ica l surface),而在囊胚阶段主要在滋胚层细胞中表达,内细胞团没有表达.
文摘The region between the preexisting and nascent membranes of a cleaving Rana egg is a dense protrusion region of nearly 40μm wide at 180° stage.Later,this region differentiate,into an upper part,a strip with long,branched and randomly distributed protrusions which are derived largely from the preexisting membrane and a lower part,a band with microvilli.During 4-and 8-cell stages,the strip is almost vanished and microvilli in the band is shortened.The nascent membrane is smooth at the 180° stage,then a rough area appears below the smooth region and quickly expands,wheat germ agglutini which can bind to preexisting membrane interrupts the development of the region between the preexisting and nascent membranes Detergent,Brij,having the property to increase the area of nascent membrane,does not interupt the development of the region between the preexisting and nascent membranes.
文摘By laser scanning fluorescence microscopy for quan-titative measurement of fluorescence intensity changes on egg surface stained with fluorescein isothiocyanate duxing cleavage furrow extending forward, it was found that in area of presumptive cleavage furrow the scanning curve became ∨ shape, indicating dark stripe appeared in that place. Then the fluorescence intensity increased at the place where the botton of ∨ shape had located, and the scanning curve tuxned to ∧ shape, indicating single stripe was formed. While enhanced fluorescence appeared on the borders of ∧ shape, an M shape curve was found, show-ing double stripe occurred. During the distance between two borders of M shape incresing from 50 μm to 100μm,a fluorescence peak came to sight in the middle of the M shape, which being the cleavge furrow bottom. The two lateral sides of furrow bottom with decreasing fluorescence were nascent membrane. At that time the curve became W shape. By the sides of cleavage furrow the the stress folds became conspicous after double stripe stage, showing the stretching of the egg surface being increased. With our[31, 33] and others[32] reports that polylysine could induce the appearance of nascent membrane and phyto-hemagglutinins could decrease or prevent the appearance of nascent membrane, we believed the idea of Schroeder[25] that increasing mechanical stress could initiate nascent membrane formation and thought that the stress lay to the outsides of cleavage furrow.
文摘Cell couplings before and after neural induction in embryos of Cynops orientalis were studied by means of single cell injection of Lucifer Yellow.Differences both in incidence and the extent of cell couplings were demonstrated.Results of cell couplings were correlated with electron microscopic observations of freeze-etching replicas.
