First comprehensive investigations of the Cuonadong leucogranite exposed in North Himalayan gneiss dome of southern Tibet are presented in this study.The SIMS U–Pb ages of oscillatory zircon rims scatter in a wide ra...First comprehensive investigations of the Cuonadong leucogranite exposed in North Himalayan gneiss dome of southern Tibet are presented in this study.The SIMS U–Pb ages of oscillatory zircon rims scatter in a wide range from 34.1 to 16.0 Ma, and the Cuonadong leucogranite probably emplaced at 16.0 Ma. High-precision ^(40)Ar/^(39)Ar dating on a muscovite sample yields an essentially flat age spectrum with consistent plateau and isochron ages, indicating that the Cuonadong leucogranite cooled below 450 °C at 14 Ma. Based on the youngest zircon U–Pb age and muscovite^(40)Ar/^(39)Ar age, the Cuonadong leucogranite experienced rapid cooling with a rate of 119 °C/Myr from 16 to 14 Ma. The geochronological data of this undeformed leucogranite also suggest that the ductile extension of the South Tibetan Detachment System in the eastern Himalaya ceased by ca. 14 Ma. Furthermore,the initial Sr–Nd isotopic compositions and Nd model ages demonstrate that the leucogranite was derived from metapelitic source within the Greater Himalayan Crystalline Complex. The distinct Ba depletion with high Rb/Sr ratios and negative Eu anomalies make it clear that the leucogranite melts were generated by breakdown of muscovite under fluid-absent conditions.展开更多
The bone marrow mesenchymal stem cells （MSCs） are multipotent stem cells which can differentiate into mesenchymal cells in vitro. In this study, MSCs in duck were isolated from bone marrow by density gradient centri...The bone marrow mesenchymal stem cells （MSCs） are multipotent stem cells which can differentiate into mesenchymal cells in vitro. In this study, MSCs in duck were isolated from bone marrow by density gradient centrifuge separation, purified and expanded in the me- dium. The primary MSCs were expanded for 11 passages. The different-passage MSCs were induced to differentiate into osteoblasts and neuron-like cells. Karyotype analysis indicated that MSCs kept diploid condition and the hereditary feature was stable. The different- passage MSCs expressed CD44, ICAM-1 and SSEA-4, but not CD34, CD45 and SSEA-1 when detected by immunofluorescence staining There was no significant difference among the positive rates of passages 2, 6 and 8 （P 〉 0.05）, but a significant difference existed among those of passages 2, 6, 8 and 11 （P 〈 0.05）. After the osteogenic inducement was added, the induced different-passage MSCs expressed high-level alkaline phosphatase （ALP）, and are positive for tetracycline staining, Alizarin Red staining and Von Kossa staining. After the neural inducement was added, about 70% cells exhibited typical neuron-like phenotype, the induced different-passage MSCs expressed Nestin, neuron-specific enolase （NSE） and glial fibrillary acidic protein （GFAP） when detected by immunofluorescence staining. There was no significant difference among the positive rates of passages 3, 4 and 6 （P〉0.05）, but a significant difference existed among those of passages 3, 4, 6 and 8 （P〈0.05）. These results suggest that MSCs in duck were capable of differentiating into osteoblasts and neuron-like cells in vitro.展开更多
MicroRNAs are -22 nt long small non-coding RNAs that play important regulatory roles in eukaryotes. The biogenesis and functional processes of microRNAs require the participation of many proteins, of which, the well s...MicroRNAs are -22 nt long small non-coding RNAs that play important regulatory roles in eukaryotes. The biogenesis and functional processes of microRNAs require the participation of many proteins, of which, the well studied ones are Dicer, Drosha, Argonaute and Exportin 5. To systematically study these four protein families, we screened 11 animal genomes to search for genes encoding above mentioned proteins, and identified some new members for each family. Domain analysis results revealed that most proteins within the same family share identical or similar domains. Alternative spliced transcript variants were found for some proteins. We also examined the expression patterns of these proteins in different human tissues and identified other proteins that could potentially interact with these proteins. These findings provided systematic information on the four key proteins involved in microRNA biogenesis and functional pathways in animals, and will shed light on further functional studies of these proteins.展开更多
Cerium is one of multivalent rear earth elements, which can transfer from trivalence to tretavalence at oxidizing environment. This process may cause variable degrees of fractionation of Ce from other trivalent rear e...Cerium is one of multivalent rear earth elements, which can transfer from trivalence to tretavalence at oxidizing environment. This process may cause variable degrees of fractionation of Ce from other trivalent rear earth elements, and thus may provide specific insight into the geological processes associated with marked redoxomorphism. Multiple geochemical tracing of Sr-Nd-Ce isotopes are performed on the felsic and mafic intrusives of the Neoproterozoic（~800 Ma） Huangling complex located at the eastern Three Gorges, South China. The intrusive rocks exclusively show various extents of negative Ce anomalies. On the εCe-εNd plot, most samples from the mafic intrusions scatter within the second quadrant, whereas those from the felsic intrusions within the fourth Quadrant. Both of the two groups exhibit relatively large range of ？Ce（t） variation but limited ？Nd（t） range, which cause a deviation from the ＂crustal array＂ and reveal a decoupled Nd-Ce isotope correlation. The intermediate-felsic suite have varied Ce/Ce＊ ratios but broadly proximate εCe（t） values, indicating that their negative Ce anomalies were generated during the magmatism; on the contrary, a positive correlation between εCe（t） and Ce/Ce＊ is observed for the intermediate-mafic suite, an indication of an origin of post-magmatic alteration or metamorphism for their Ce anomalies. Calculation of model age, the occurrence age of negative Ce anomalies（TCe） for the intermediate-mafic samples infers that the alteration events took place 〉350 Ma. Data showed that negative Ce anomalies of the felsic intrusions may reflect an increase of oxygen fugacity during magma ascending, rather than an inheritance from their source rocks. This explanation implies that the Neoproterozoic magmatism occurred at the continental nucleus of the Yangtze block were developing at a geodynamic context of rapidly regional uplifting.展开更多
Identifying the mechanism for sex determination in amphibians is challenging.Very little is known about sex determination mechanisms of Rana dybowskii,a species of importance to evolutionary and conservation biology.W...Identifying the mechanism for sex determination in amphibians is challenging.Very little is known about sex determination mechanisms of Rana dybowskii,a species of importance to evolutionary and conservation biology.We screened for sex-linked molecular markers in R.dybowskii in China using target region amplification polymorphism with 2 fixed primers against the sequences of Dmrt1.We found 2 male-linked molecular markers in R.dybowskii,which were 222 bp and 261 bp long.The detection rates of 222 bp marker in males form Xinglong,Huadian,and Dandong were 93.79%,69.64%,and 13.64%,respectively,while the rate in females from Huadian was 27.50%.Besides,the detection rates of 261 bp marker in the above 3 regions were only observed in males at the rate of 93.79%,87.50%,and 32.73%,respectively.The inheritance patterns of sex-linked molecular markers showed that the 2 sex-linked molecular markers were heterozygous.Compared to the XY-male parent,progeny from XX-pseudo-male parent possessed lower sex reversal ratio at the same rearing temperature,and the proportion of female froglets from an XX-pseudo-male parent was more than 95%at low rearing temperature(15°C).Our findings suggest that R.dybowskii displays male heterogamety,and the 2 sex-linked molecular markers may have a guiding significance for the protection and utilization of R.dybowskii.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41630315,41503053 and 41688103)
文摘First comprehensive investigations of the Cuonadong leucogranite exposed in North Himalayan gneiss dome of southern Tibet are presented in this study.The SIMS U–Pb ages of oscillatory zircon rims scatter in a wide range from 34.1 to 16.0 Ma, and the Cuonadong leucogranite probably emplaced at 16.0 Ma. High-precision ^(40)Ar/^(39)Ar dating on a muscovite sample yields an essentially flat age spectrum with consistent plateau and isochron ages, indicating that the Cuonadong leucogranite cooled below 450 °C at 14 Ma. Based on the youngest zircon U–Pb age and muscovite^(40)Ar/^(39)Ar age, the Cuonadong leucogranite experienced rapid cooling with a rate of 119 °C/Myr from 16 to 14 Ma. The geochronological data of this undeformed leucogranite also suggest that the ductile extension of the South Tibetan Detachment System in the eastern Himalaya ceased by ca. 14 Ma. Furthermore,the initial Sr–Nd isotopic compositions and Nd model ages demonstrate that the leucogranite was derived from metapelitic source within the Greater Himalayan Crystalline Complex. The distinct Ba depletion with high Rb/Sr ratios and negative Eu anomalies make it clear that the leucogranite melts were generated by breakdown of muscovite under fluid-absent conditions.
基金supported by the National High-Tech Research and Development Program of China (863 Pro-gram) (No. 2006AA10Z198 and 2007AA10Z170)the National Infrastructure of Natural Science and Technology Program (No. 2005DKA21101)the National Scientific Foundation of China (No. 30671539).
文摘The bone marrow mesenchymal stem cells （MSCs） are multipotent stem cells which can differentiate into mesenchymal cells in vitro. In this study, MSCs in duck were isolated from bone marrow by density gradient centrifuge separation, purified and expanded in the me- dium. The primary MSCs were expanded for 11 passages. The different-passage MSCs were induced to differentiate into osteoblasts and neuron-like cells. Karyotype analysis indicated that MSCs kept diploid condition and the hereditary feature was stable. The different- passage MSCs expressed CD44, ICAM-1 and SSEA-4, but not CD34, CD45 and SSEA-1 when detected by immunofluorescence staining There was no significant difference among the positive rates of passages 2, 6 and 8 （P 〉 0.05）, but a significant difference existed among those of passages 2, 6, 8 and 11 （P 〈 0.05）. After the osteogenic inducement was added, the induced different-passage MSCs expressed high-level alkaline phosphatase （ALP）, and are positive for tetracycline staining, Alizarin Red staining and Von Kossa staining. After the neural inducement was added, about 70% cells exhibited typical neuron-like phenotype, the induced different-passage MSCs expressed Nestin, neuron-specific enolase （NSE） and glial fibrillary acidic protein （GFAP） when detected by immunofluorescence staining. There was no significant difference among the positive rates of passages 3, 4 and 6 （P〉0.05）, but a significant difference existed among those of passages 3, 4, 6 and 8 （P〈0.05）. These results suggest that MSCs in duck were capable of differentiating into osteoblasts and neuron-like cells in vitro.
基金supported by grants from the Ministry of Science and Technology of China (No. 2007CB946901)the Natural Science Foundation of China (No. 30725014 and 90612019)the Chinese Academy of Sciences (No. KSCX2-YW-R-134)
文摘MicroRNAs are -22 nt long small non-coding RNAs that play important regulatory roles in eukaryotes. The biogenesis and functional processes of microRNAs require the participation of many proteins, of which, the well studied ones are Dicer, Drosha, Argonaute and Exportin 5. To systematically study these four protein families, we screened 11 animal genomes to search for genes encoding above mentioned proteins, and identified some new members for each family. Domain analysis results revealed that most proteins within the same family share identical or similar domains. Alternative spliced transcript variants were found for some proteins. We also examined the expression patterns of these proteins in different human tissues and identified other proteins that could potentially interact with these proteins. These findings provided systematic information on the four key proteins involved in microRNA biogenesis and functional pathways in animals, and will shed light on further functional studies of these proteins.
基金supported by the National Natural Science Foundation of China (Nos. 41373037, 41173048, 41503025)
文摘Cerium is one of multivalent rear earth elements, which can transfer from trivalence to tretavalence at oxidizing environment. This process may cause variable degrees of fractionation of Ce from other trivalent rear earth elements, and thus may provide specific insight into the geological processes associated with marked redoxomorphism. Multiple geochemical tracing of Sr-Nd-Ce isotopes are performed on the felsic and mafic intrusives of the Neoproterozoic（~800 Ma） Huangling complex located at the eastern Three Gorges, South China. The intrusive rocks exclusively show various extents of negative Ce anomalies. On the εCe-εNd plot, most samples from the mafic intrusions scatter within the second quadrant, whereas those from the felsic intrusions within the fourth Quadrant. Both of the two groups exhibit relatively large range of ？Ce（t） variation but limited ？Nd（t） range, which cause a deviation from the ＂crustal array＂ and reveal a decoupled Nd-Ce isotope correlation. The intermediate-felsic suite have varied Ce/Ce＊ ratios but broadly proximate εCe（t） values, indicating that their negative Ce anomalies were generated during the magmatism; on the contrary, a positive correlation between εCe（t） and Ce/Ce＊ is observed for the intermediate-mafic suite, an indication of an origin of post-magmatic alteration or metamorphism for their Ce anomalies. Calculation of model age, the occurrence age of negative Ce anomalies（TCe） for the intermediate-mafic samples infers that the alteration events took place 〉350 Ma. Data showed that negative Ce anomalies of the felsic intrusions may reflect an increase of oxygen fugacity during magma ascending, rather than an inheritance from their source rocks. This explanation implies that the Neoproterozoic magmatism occurred at the continental nucleus of the Yangtze block were developing at a geodynamic context of rapidly regional uplifting.
基金funded by China Postdoctoral Science Foundation(No.2021M690577)the Post-Doctoral Fund of Heilongjiang Province(No.LBH-Z20113).
文摘Identifying the mechanism for sex determination in amphibians is challenging.Very little is known about sex determination mechanisms of Rana dybowskii,a species of importance to evolutionary and conservation biology.We screened for sex-linked molecular markers in R.dybowskii in China using target region amplification polymorphism with 2 fixed primers against the sequences of Dmrt1.We found 2 male-linked molecular markers in R.dybowskii,which were 222 bp and 261 bp long.The detection rates of 222 bp marker in males form Xinglong,Huadian,and Dandong were 93.79%,69.64%,and 13.64%,respectively,while the rate in females from Huadian was 27.50%.Besides,the detection rates of 261 bp marker in the above 3 regions were only observed in males at the rate of 93.79%,87.50%,and 32.73%,respectively.The inheritance patterns of sex-linked molecular markers showed that the 2 sex-linked molecular markers were heterozygous.Compared to the XY-male parent,progeny from XX-pseudo-male parent possessed lower sex reversal ratio at the same rearing temperature,and the proportion of female froglets from an XX-pseudo-male parent was more than 95%at low rearing temperature(15°C).Our findings suggest that R.dybowskii displays male heterogamety,and the 2 sex-linked molecular markers may have a guiding significance for the protection and utilization of R.dybowskii.
