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
In crab, embryogenesis is a complicated developmental program marked by a series of critical events. RNA-Sequencing technology offers developmental biologists a way to identify many more developmental genes than ever ...In crab, embryogenesis is a complicated developmental program marked by a series of critical events. RNA-Sequencing technology offers developmental biologists a way to identify many more developmental genes than ever before. Here, we present a comprehensive analysis of the transcriptomes of Eriocheir sinensis oosperms （Os） and embryos at the 2-4, cell stage （Cs）, which are separated by a cleavage event. Atotal of 18 923 unigenes were identified, and 403 genes matched with gene ontology （GO） terms related to developmental processes. In total, 432 differentially expressed genes （DEGs） were detected between the two stages. Nine DEGs were specifically expressed at only one stage. These DEGs may be relevant to stage-specific molecular events during development. A number of DEGs related to ＇hedgehog signaling pathway＇, ＇Wnt signaling pathway＇ ＇germplasm＇, ＇nervous system＇, ＇sensory perception＇ and ＇segment polarity＇ were identified as being up-regulated at the Cs stage. The results suggest that these embryonic developmental events begin before the early cleavage event in crabs, and that many of the genes expressed in the two transeriptomes might be maternal genes. Our study provides ample information for further research on the molecular mechanisms underlying crab development.展开更多
We isolated and purified mitochondria from mouse livers and spinach leaves. When added into egg extracts of Xenopus laevis, they caused nuclei of mouse liver to undergo apoptotic changes. Chromatin condensation, margi...We isolated and purified mitochondria from mouse livers and spinach leaves. When added into egg extracts of Xenopus laevis, they caused nuclei of mouse liver to undergo apoptotic changes. Chromatin condensation, margination and DNA ladder were observed. After incubating isolated mitochondria in some hypotonic solutions, and centrifuging these mixtures at high speed, we got mitochondrial supernatants. It was found that in the absence of cytosolic factor, the supernatant alone was able to induce apoptotic changes in nuclei. The effective components were partly of protein. DNA fragmentation was partly inhibited by caspase inhibitors AC-DEVD-CHO and AC- YVADCHO. Meanwhile, caspase inhibitors fully blocked chromatin condensation. Primary characterization of the nuclear endonuclease(s) induced by mitochondrial supernatants was also conducted. It was found that this endonuclease is different from endonuclease G, cytochrome c-induced nuclease, or Ca2+-activated endonuclease.展开更多
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.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(No.2012AA10A409)the Scientific and Technological Innovation Project of Qingdao National Laboratory for Marine Science and Technology(No.2015ASKJ02)the National Natural Science Foundation of China(Nos.41276165 to Dr.CUI Zhaoxia,31302187 to Dr.HUI Min)
文摘In crab, embryogenesis is a complicated developmental program marked by a series of critical events. RNA-Sequencing technology offers developmental biologists a way to identify many more developmental genes than ever before. Here, we present a comprehensive analysis of the transcriptomes of Eriocheir sinensis oosperms （Os） and embryos at the 2-4, cell stage （Cs）, which are separated by a cleavage event. Atotal of 18 923 unigenes were identified, and 403 genes matched with gene ontology （GO） terms related to developmental processes. In total, 432 differentially expressed genes （DEGs） were detected between the two stages. Nine DEGs were specifically expressed at only one stage. These DEGs may be relevant to stage-specific molecular events during development. A number of DEGs related to ＇hedgehog signaling pathway＇, ＇Wnt signaling pathway＇ ＇germplasm＇, ＇nervous system＇, ＇sensory perception＇ and ＇segment polarity＇ were identified as being up-regulated at the Cs stage. The results suggest that these embryonic developmental events begin before the early cleavage event in crabs, and that many of the genes expressed in the two transeriptomes might be maternal genes. Our study provides ample information for further research on the molecular mechanisms underlying crab development.
基金the National Natural Science Fundation of China(Grant No. 39800075 and 19890380) and the special Funds for Major StateBasic
文摘We isolated and purified mitochondria from mouse livers and spinach leaves. When added into egg extracts of Xenopus laevis, they caused nuclei of mouse liver to undergo apoptotic changes. Chromatin condensation, margination and DNA ladder were observed. After incubating isolated mitochondria in some hypotonic solutions, and centrifuging these mixtures at high speed, we got mitochondrial supernatants. It was found that in the absence of cytosolic factor, the supernatant alone was able to induce apoptotic changes in nuclei. The effective components were partly of protein. DNA fragmentation was partly inhibited by caspase inhibitors AC-DEVD-CHO and AC- YVADCHO. Meanwhile, caspase inhibitors fully blocked chromatin condensation. Primary characterization of the nuclear endonuclease(s) induced by mitochondrial supernatants was also conducted. It was found that this endonuclease is different from endonuclease G, cytochrome c-induced nuclease, or Ca2+-activated endonuclease.
文摘为了研究白乌鳢胚胎发育各个阶段的形态变化以及发育时序,试验通过显微观察并拍摄白乌鳢(Opniocepnalus argus)胚胎发育及胚后发育过程的形态特征,并对白乌鳢胚胎发育各时期特征进行了详细描述。结果表明:成熟白乌鳢卵为球形、桔黄色,为浮性卵,有油球,卵径为(2.35±0.05)mm,吸水膨胀后直径达(2.59±0.08)mm。在水温26~28℃条件下,受精卵在受精50 min后开始第一次卵裂,受精22 h 58 min后开始形成器官,受精41 h 48 min后孵出仔鱼,积温1 082.92℃。初孵仔鱼全长为(5.62±0.26)mm,卵黄囊大。根据白乌鳢胚胎发育过程中的形态特点,可将白乌鳢的胚胎发育过程分为7个阶段、27个发育期。
