Dimethylations of histone H3 lysine 9 and lysine 27 are important epigenetic marks associated with transcription repression. Here, we identified KIAA1718 （KDM7A） as a novel histone demethylase specific for these two...Dimethylations of histone H3 lysine 9 and lysine 27 are important epigenetic marks associated with transcription repression. Here, we identified KIAA1718 （KDM7A） as a novel histone demethylase specific for these two repressing marks. Using mouse embryonic stem cells, we demonstrated that KIAA1718 expression increased at the early phase of neural differentiation. Knockdown of the gene blocked neural differentiation and the effect was rescued by the wild-type human gene, and not by a catalytically inactive mutant. In addition, overexpression of KIAA1718 accelerated neural differentiation. We provide the evidence that the pro-neural differentiation effect of KDM7A is mediated through direct transcriptional activation of FGF4, a signal molecule implicated in neural differentiation. Thus, our study identified a dual-specificity histone demethylase that regulates neural differentiation through FGF4.展开更多
The complex transformation of a tadpole to a frogduring amphibian development is under the control of thyroid hormone (T3). T3 is known to regulate gene transcription through its nuclear receptors. We have previouslyi...The complex transformation of a tadpole to a frogduring amphibian development is under the control of thyroid hormone (T3). T3 is known to regulate gene transcription through its nuclear receptors. We have previouslyisolated many genes which are up-regulated by T3 in theintestine of Xenopus laevis tadpoles. We have now cloneda full- length cDNA for one such gene (IU12). Sequenceanalysis shows that the IU12 cDNA encodes a plasmamembrane protein with 12 transmembrane domains andhomologous to a mammalian gene associated with cell activation and organ development. Similarly, we have foundthat IU12 is activated during intestinal remodeling whenboth cell death and proliferation take place. Furthermore,IU12 is an early T3-response gene and its expression in theintestine during T3-induced metamorphosis mimics thatduring normal development. These results argue for a roleof IU12 in the signal transduction pathways leading to intestinal metamorphosis.展开更多
The influences of different alkaline conditions on the kinds and morphologies of steel slag＇s hydration products, Ca（OH）2 con- tent of hydration products, pore stiucture of hardened paste, non-evaporable water cont...The influences of different alkaline conditions on the kinds and morphologies of steel slag＇s hydration products, Ca（OH）2 con- tent of hydration products, pore stiucture of hardened paste, non-evaporable water content of hydration products, and strength of steel slag mortar were investigated by changing the initial alkalinity of the hydration condition of steel slag. The results showed that increasing the initial alkalinity of hydration condition can promote the early hydration of steel slag＇s active com- ponents （e,g., C2S, C3S, and C12A7）, but it has little influence on their late-age hydration degree. The hydration degree of non-active components （e.g., RO phase and Fe304） of steel slag is very low even under strong alkaline condition with pH value of 13.8. The excitation effect of alkaline condition on the early hydration of steel slag is more obvious with the increase of pH value, but the kinds of steel slag＇s hydration products are not influenced by changing the alkaline condition. The amount of steel slag＇s hydration products is limited, so the strength of alkali-activated steel slag mortar is very low though the strong al- kaline condition significantly promotes the early hydration of steel slag. Steel slag is not an ideal raw material for alka- li-activated cementitious material.展开更多
The effect of total dissolved gas （TDG） supersaturation on fish living downstream of dams is one of the main ecological risks of high dam construction. A strategy for mitigating the negative effects is needed urgent...The effect of total dissolved gas （TDG） supersaturation on fish living downstream of dams is one of the main ecological risks of high dam construction. A strategy for mitigating the negative effects is needed urgently since many high dams are under construction in the upper reaches of the Yangtze River in China. Experiments on the hatching process of David＇s schizothoracin were carried out and the results show that the hatching rate decreased with increasing TDG levels, and that most eggs hatched within a very short time in the higher TDG saturation groups. By using a stereomicroscope, damages to the head, yolk sac, body, anus, etc. were found in larvae which hatched in TDG supersaturated water. Results show that the lesion rate increased with increasing TDG levels. Furthermore, 7-d-old David＇s schizothoracin were exposed to TDG supersaturated water levels of 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, and 140% for testing their tolerance to TDG supersaturation. We found that the median lethal concentrations （LC50） for 13, 14, 20, 35, 52, 73, and 96 h exposure were 138%, 138%, 134%, 130%, 129%, 128%, and 126%, respectively. The median lethal times （LTs0） were 7.49, 11.04, 19.25, and 35.38 h for exposure to water with TDG levels of 145%, 140%, 135%, and 130%, respectively.展开更多
The growth rate of solar activity in the early phase of a solar cycle has been known to be well correlated with the subsequent amplitude （solar maximum）. It provides very useful information for a new solar cycle as ...The growth rate of solar activity in the early phase of a solar cycle has been known to be well correlated with the subsequent amplitude （solar maximum）. It provides very useful information for a new solar cycle as its variation reflects the temporal evolution of the dynamic process of solar magnetic activities from the initial phase to the peak phase of the cycle. The correlation coefficient between the solar maximum （Rmax） and the rising rate （βa） at Am months after the solar minimum （Rmin） is studied and shown to increase as the cycle progresses with an inflection point （r = 0.83） at about Am = 20 months. The prediction error of Rmax based on βa is found within estimation at the 90% level of confidence and the relative prediction error will be less than 20% when Am ≥ 20. From the above relationship, the current cycle （24） is preliminarily predicted to peak around October, 2013 with a size of Rmax = 84 ＋ 33 at the 90% level of confidence.展开更多
Aurora kinases have become a hot topic for research as they have been found to play an important role in various stages of mitotic cell division and to participate in malignant conversions of tumors. The participation...Aurora kinases have become a hot topic for research as they have been found to play an important role in various stages of mitotic cell division and to participate in malignant conversions of tumors. The participation of Aurora kinases in the regulation of oocyte meiosis has been recently reported, but their participation in mammalian early embryonic development remained unclear. The object of our study was to establish the spatio-temporal expression pattern of Aurora kinase B (AURKB) in mouse zygotes during the first cleavage, to reveal its functions in the early development of mouse zygotes, and to define the involvement of AURKB in mitogen-activated protein kinase (MAPK) signaling. Our results showed that in mouse zygotes AURKB expression increased in G1 phase and peaked in M phase. AURKB protein distribution was found to be in association with nuclei and distributed throughout the cytoplasm in a cell cycle-dependent manner. Functional disruption of AURKB resulted in abnormal division phenotypes or mitotic impairments. U0126, a specific mitogen-activated protein kinase kinase (MEK) inhibitor, caused significantly altered morphologies of early embryos together with a decrease in protein expression and kinase activity of AURKB. Our results indicated that the activity of AURKB was required for regulating multiple stages of mitotic progression in the early development of mouse zygotes and was correlated with the activation of the MAPK pathway.展开更多
基金Supplementary information is linked to the online version of the paper on the Cell Research website.Acknowledgments We thank Anning Lin （The University of Chicago） for the critical reading of the paper, members in the Chen lab for technical help, the cell biology and molecular biology core facilities for confocal study and Q-PCR, and Shanghai Biochip Co Ltd. for microarray analysis. The H3K27me2 antibody was kindly provided by Li Tang （Fudan University） and Thomas Jenuwein （Research Institute of Molecular Pathology, The Vienna Biocenter）. This work was supported by the National Basic Research Program of China （2007CB957900, 2006CB943902, 2007CB947101, 2008KR0695, 2009CB941100, 2005CB522704）, the Chinese Academy of Sciences （KSCX2-YW-R-04）, the National Natural Science Foundation of China （90919026, 30870538,30623003, 30721065, 30830034, 90919046）, the Shanghai Pujiang Program （0757S11361）, the Shanghai Key Project of Basic Science Research （06DJ14001, 06DZ22032, 08DJ1400501）, and the Council of Shanghai Municipal Government for Science and Technology （088014199）.
文摘Dimethylations of histone H3 lysine 9 and lysine 27 are important epigenetic marks associated with transcription repression. Here, we identified KIAA1718 （KDM7A） as a novel histone demethylase specific for these two repressing marks. Using mouse embryonic stem cells, we demonstrated that KIAA1718 expression increased at the early phase of neural differentiation. Knockdown of the gene blocked neural differentiation and the effect was rescued by the wild-type human gene, and not by a catalytically inactive mutant. In addition, overexpression of KIAA1718 accelerated neural differentiation. We provide the evidence that the pro-neural differentiation effect of KDM7A is mediated through direct transcriptional activation of FGF4, a signal molecule implicated in neural differentiation. Thus, our study identified a dual-specificity histone demethylase that regulates neural differentiation through FGF4.
文摘The complex transformation of a tadpole to a frogduring amphibian development is under the control of thyroid hormone (T3). T3 is known to regulate gene transcription through its nuclear receptors. We have previouslyisolated many genes which are up-regulated by T3 in theintestine of Xenopus laevis tadpoles. We have now cloneda full- length cDNA for one such gene (IU12). Sequenceanalysis shows that the IU12 cDNA encodes a plasmamembrane protein with 12 transmembrane domains andhomologous to a mammalian gene associated with cell activation and organ development. Similarly, we have foundthat IU12 is activated during intestinal remodeling whenboth cell death and proliferation take place. Furthermore,IU12 is an early T3-response gene and its expression in theintestine during T3-induced metamorphosis mimics thatduring normal development. These results argue for a roleof IU12 in the signal transduction pathways leading to intestinal metamorphosis.
基金supported by the National Natural Science Foundation of China (Grant No. 51108245)the National Basic Research Program of China ("973" Project) (Grant No. 2009CB623106)
文摘The influences of different alkaline conditions on the kinds and morphologies of steel slag＇s hydration products, Ca（OH）2 con- tent of hydration products, pore stiucture of hardened paste, non-evaporable water content of hydration products, and strength of steel slag mortar were investigated by changing the initial alkalinity of the hydration condition of steel slag. The results showed that increasing the initial alkalinity of hydration condition can promote the early hydration of steel slag＇s active com- ponents （e,g., C2S, C3S, and C12A7）, but it has little influence on their late-age hydration degree. The hydration degree of non-active components （e.g., RO phase and Fe304） of steel slag is very low even under strong alkaline condition with pH value of 13.8. The excitation effect of alkaline condition on the early hydration of steel slag is more obvious with the increase of pH value, but the kinds of steel slag＇s hydration products are not influenced by changing the alkaline condition. The amount of steel slag＇s hydration products is limited, so the strength of alkali-activated steel slag mortar is very low though the strong al- kaline condition significantly promotes the early hydration of steel slag. Steel slag is not an ideal raw material for alka- li-activated cementitious material.
基金Project (No. 50979063) supported by the National Natural Science Foundation of China
文摘The effect of total dissolved gas （TDG） supersaturation on fish living downstream of dams is one of the main ecological risks of high dam construction. A strategy for mitigating the negative effects is needed urgently since many high dams are under construction in the upper reaches of the Yangtze River in China. Experiments on the hatching process of David＇s schizothoracin were carried out and the results show that the hatching rate decreased with increasing TDG levels, and that most eggs hatched within a very short time in the higher TDG saturation groups. By using a stereomicroscope, damages to the head, yolk sac, body, anus, etc. were found in larvae which hatched in TDG supersaturated water. Results show that the lesion rate increased with increasing TDG levels. Furthermore, 7-d-old David＇s schizothoracin were exposed to TDG supersaturated water levels of 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, and 140% for testing their tolerance to TDG supersaturation. We found that the median lethal concentrations （LC50） for 13, 14, 20, 35, 52, 73, and 96 h exposure were 138%, 138%, 134%, 130%, 129%, 128%, and 126%, respectively. The median lethal times （LTs0） were 7.49, 11.04, 19.25, and 35.38 h for exposure to water with TDG levels of 145%, 140%, 135%, and 130%, respectively.
基金supported by the National Natural Science Foundation of China (Grant Nos.10973020,40890161 and 10921303)the National Basic Research Program of China (Grant No.2011CB811406)the China Meteorological Administration (Grant No.GYHY201106011)
文摘The growth rate of solar activity in the early phase of a solar cycle has been known to be well correlated with the subsequent amplitude （solar maximum）. It provides very useful information for a new solar cycle as its variation reflects the temporal evolution of the dynamic process of solar magnetic activities from the initial phase to the peak phase of the cycle. The correlation coefficient between the solar maximum （Rmax） and the rising rate （βa） at Am months after the solar minimum （Rmin） is studied and shown to increase as the cycle progresses with an inflection point （r = 0.83） at about Am = 20 months. The prediction error of Rmax based on βa is found within estimation at the 90% level of confidence and the relative prediction error will be less than 20% when Am ≥ 20. From the above relationship, the current cycle （24） is preliminarily predicted to peak around October, 2013 with a size of Rmax = 84 ＋ 33 at the 90% level of confidence.
基金supported by the National Natural Science Foundation of China (Grant No. 81070527)
文摘Aurora kinases have become a hot topic for research as they have been found to play an important role in various stages of mitotic cell division and to participate in malignant conversions of tumors. The participation of Aurora kinases in the regulation of oocyte meiosis has been recently reported, but their participation in mammalian early embryonic development remained unclear. The object of our study was to establish the spatio-temporal expression pattern of Aurora kinase B (AURKB) in mouse zygotes during the first cleavage, to reveal its functions in the early development of mouse zygotes, and to define the involvement of AURKB in mitogen-activated protein kinase (MAPK) signaling. Our results showed that in mouse zygotes AURKB expression increased in G1 phase and peaked in M phase. AURKB protein distribution was found to be in association with nuclei and distributed throughout the cytoplasm in a cell cycle-dependent manner. Functional disruption of AURKB resulted in abnormal division phenotypes or mitotic impairments. U0126, a specific mitogen-activated protein kinase kinase (MEK) inhibitor, caused significantly altered morphologies of early embryos together with a decrease in protein expression and kinase activity of AURKB. Our results indicated that the activity of AURKB was required for regulating multiple stages of mitotic progression in the early development of mouse zygotes and was correlated with the activation of the MAPK pathway.
