In eukaryotic cells,the smallest subunit of chromatin is the nucleosome,which consists of a segment of DNA wound on histone protein cores. Despite many years of effort,the process of nucleosome assembly and disassembl...In eukaryotic cells,the smallest subunit of chromatin is the nucleosome,which consists of a segment of DNA wound on histone protein cores. Despite many years of effort,the process of nucleosome assembly and disassembly is still not very clear. Here,we present a convenient method to investigate the process of nucleosome assembly at the single molecule level. We invented a novel system derived from the yeast nucleoplasmic extracts(YNPE),and demonstrated that the YNPE supports the nucleosome assembly under physiological condition. By combining the total internal reflection fluorescence microscopy with microfluidic flow-cell technique,the dynamic process of nucleosome assembly in YNPE was visualized at single-molecule level. Our system provides a novel in vitro single-molecule tool to investigate the dynamics of nucleosome assembly under physiological conditions.展开更多
AIM:To evaluate the occurrence of micronucleus(MN),nucleoplasmic bridges(NPBs)and nuclear buds(NBUDs)in the mitogen-stimulated lymphocytes of patients with non-alcoholic steatohepatitis(NASH).METHODS:The study was per...AIM:To evaluate the occurrence of micronucleus(MN),nucleoplasmic bridges(NPBs)and nuclear buds(NBUDs)in the mitogen-stimulated lymphocytes of patients with non-alcoholic steatohepatitis(NASH).METHODS:The study was performed in 25(9 females,16 males)patients newly diagnosed with NASH,and 25healthy subjects of similar ages and genders were used as a control group.None of the controls was known to be receiving any drugs for medical or other reasons or using alcohol.Hepatosteatosis was further excluded by abdominal ultrasound imaging in the control group.The numbers of MN,NPBs and NBUDs scored in binucleated(BN)cells were obtained from the mitogen-stimulated lymphocytes of patients and control subjects.Statistical comparisons of the numbers of BN cells with MN,NPBs and NBUDs and ages between the patients with NASH and control subjects were performed.RESULTS:The mean ages of the patients and the control group were 41.92±13.33 and 41.80±13.09 years(P>0.05),respectively.The values of the mean body mass index(BMI),HOMA-IR,hemoglobin,creatinin,aspartate aminotransferase,alanine aminotransferase,triglyceride,high density lipoprotein,and low density lipoprotein were 31.19±4.62 kg/m2vs 25.07±4.14 kg/m2,6.71±4.68 vs 1.40±0.53,14.73±1.49 g/dL vs 14.64±1.30 g/dL,0.74±0.15 mg/dL vs 0.80±0.13 mg/dL,56.08±29.11 U/L vs 16.88±3.33 U/L,92.2±41.43U/L vs 15.88±5.88 U/L,219.21±141.68 mg/dL vs102.56±57.98 mg/dL,16.37±9.65 mg/dL vs 48.72±15.31 mg/dL,and 136.75±30.14 mg/dL vs 114.63±34.13 mg/dL in the patients and control groups,respectively.The total numbers and frequencies of BN cells with MN,NPBs and NBUDs,which were scored using the CBMN cytome assay on PHA-stimulated lymphocytes,were evaluated in the patients with NASH and control group.We found significantly higher numbers of MN,NPBs and NBUDs in the BN cells of patients with NASH than in those of the control subjects(21.60±9.32vs 6.88±3.91;29.28±13.31 vs 7.84±3.96;15.60±5.55 vs 4.20±1.63,respectively,P<0.0001).CONCLUSION:The increased numbers of MN,NPBs and NBUDs observed in the lymphocytes obtained from patients with NASH may reflect genomic instability.展开更多
Cytogenetic indicators,especially dicentric chromosomes,have been globally considered the gold standard of biological dose estimation for more than 60 years.The application of these indicators to biological dose estim...Cytogenetic indicators,especially dicentric chromosomes,have been globally considered the gold standard of biological dose estimation for more than 60 years.The application of these indicators to biological dose estimation in victims of radiation accidents in China has undergone approximately 40 years of development and thus provides more accurate information for the clinical diagnosis and patients’treatment.This paper reviews the application and future development of cytogenetic indicators,including chromosomal aberrations(dicentric chromosomes and chromosomal translocations),cytokinesis-block micronuclei,nucleoplasmic bridges,and premature condensation chromosome ring,as biodosimeters in China.展开更多
Novel wheat bearing alloplasm was bred via nucleo substitution backcross. Through comparative study between the homonucleo heterocytoplasmic lines and homocytoplasm heteronuclear lines, it was shown that a portion of ...Novel wheat bearing alloplasm was bred via nucleo substitution backcross. Through comparative study between the homonucleo heterocytoplasmic lines and homocytoplasm heteronuclear lines, it was shown that a portion of the alloplasm types were able to produce useful genetic effects on wheat yield, grain quality, tolerance of salt and resistance to diseases. Among the species studied, the cytoplasm of Aegilops crassa, Ae. squarrosa and Ae. ventricosa contributed the best effect. Specific combination of nuclear genes and cytoplasmic genes conferred specific characteristics and degree of nucleoplasmic heterosis. The alloplasmic wheat lines with cytoplasm substituted were successfully bred with good quality and resistance to disease and harsh conditions. In particular, the new variety of nucleoplasmic hybrid having Ae. crassa cytoplasm proved the best in production test, demonstration and regional test and was consequently pre approved for large scale plantation. The probing of the genetic variations and the utilization of alloplasmic wheat was proven to be valuable for both genetic study and breeding of new varieties.展开更多
基金supported by the National Natural Science Foundation of China (31371264)CAS Interdisciplinary Innovation Team and the Newton Advanced Fellowship (NA140085) from the Royal Society
文摘In eukaryotic cells,the smallest subunit of chromatin is the nucleosome,which consists of a segment of DNA wound on histone protein cores. Despite many years of effort,the process of nucleosome assembly and disassembly is still not very clear. Here,we present a convenient method to investigate the process of nucleosome assembly at the single molecule level. We invented a novel system derived from the yeast nucleoplasmic extracts(YNPE),and demonstrated that the YNPE supports the nucleosome assembly under physiological condition. By combining the total internal reflection fluorescence microscopy with microfluidic flow-cell technique,the dynamic process of nucleosome assembly in YNPE was visualized at single-molecule level. Our system provides a novel in vitro single-molecule tool to investigate the dynamics of nucleosome assembly under physiological conditions.
文摘AIM:To evaluate the occurrence of micronucleus(MN),nucleoplasmic bridges(NPBs)and nuclear buds(NBUDs)in the mitogen-stimulated lymphocytes of patients with non-alcoholic steatohepatitis(NASH).METHODS:The study was performed in 25(9 females,16 males)patients newly diagnosed with NASH,and 25healthy subjects of similar ages and genders were used as a control group.None of the controls was known to be receiving any drugs for medical or other reasons or using alcohol.Hepatosteatosis was further excluded by abdominal ultrasound imaging in the control group.The numbers of MN,NPBs and NBUDs scored in binucleated(BN)cells were obtained from the mitogen-stimulated lymphocytes of patients and control subjects.Statistical comparisons of the numbers of BN cells with MN,NPBs and NBUDs and ages between the patients with NASH and control subjects were performed.RESULTS:The mean ages of the patients and the control group were 41.92±13.33 and 41.80±13.09 years(P>0.05),respectively.The values of the mean body mass index(BMI),HOMA-IR,hemoglobin,creatinin,aspartate aminotransferase,alanine aminotransferase,triglyceride,high density lipoprotein,and low density lipoprotein were 31.19±4.62 kg/m2vs 25.07±4.14 kg/m2,6.71±4.68 vs 1.40±0.53,14.73±1.49 g/dL vs 14.64±1.30 g/dL,0.74±0.15 mg/dL vs 0.80±0.13 mg/dL,56.08±29.11 U/L vs 16.88±3.33 U/L,92.2±41.43U/L vs 15.88±5.88 U/L,219.21±141.68 mg/dL vs102.56±57.98 mg/dL,16.37±9.65 mg/dL vs 48.72±15.31 mg/dL,and 136.75±30.14 mg/dL vs 114.63±34.13 mg/dL in the patients and control groups,respectively.The total numbers and frequencies of BN cells with MN,NPBs and NBUDs,which were scored using the CBMN cytome assay on PHA-stimulated lymphocytes,were evaluated in the patients with NASH and control group.We found significantly higher numbers of MN,NPBs and NBUDs in the BN cells of patients with NASH than in those of the control subjects(21.60±9.32vs 6.88±3.91;29.28±13.31 vs 7.84±3.96;15.60±5.55 vs 4.20±1.63,respectively,P<0.0001).CONCLUSION:The increased numbers of MN,NPBs and NBUDs observed in the lymphocytes obtained from patients with NASH may reflect genomic instability.
基金This work was supported by Key Science and Technology Project of Henan Province,China,IDs:142102310086Medical Science and Technology Reseach of Henan Province,China,IDs:LHGJ20190815。
文摘Cytogenetic indicators,especially dicentric chromosomes,have been globally considered the gold standard of biological dose estimation for more than 60 years.The application of these indicators to biological dose estimation in victims of radiation accidents in China has undergone approximately 40 years of development and thus provides more accurate information for the clinical diagnosis and patients’treatment.This paper reviews the application and future development of cytogenetic indicators,including chromosomal aberrations(dicentric chromosomes and chromosomal translocations),cytokinesis-block micronuclei,nucleoplasmic bridges,and premature condensation chromosome ring,as biodosimeters in China.
文摘Novel wheat bearing alloplasm was bred via nucleo substitution backcross. Through comparative study between the homonucleo heterocytoplasmic lines and homocytoplasm heteronuclear lines, it was shown that a portion of the alloplasm types were able to produce useful genetic effects on wheat yield, grain quality, tolerance of salt and resistance to diseases. Among the species studied, the cytoplasm of Aegilops crassa, Ae. squarrosa and Ae. ventricosa contributed the best effect. Specific combination of nuclear genes and cytoplasmic genes conferred specific characteristics and degree of nucleoplasmic heterosis. The alloplasmic wheat lines with cytoplasm substituted were successfully bred with good quality and resistance to disease and harsh conditions. In particular, the new variety of nucleoplasmic hybrid having Ae. crassa cytoplasm proved the best in production test, demonstration and regional test and was consequently pre approved for large scale plantation. The probing of the genetic variations and the utilization of alloplasmic wheat was proven to be valuable for both genetic study and breeding of new varieties.
