Objective To genetically correct a disease-causing point mutation in human induced pluripotent stem cells （iPSCs） derived from a hemophilia B patient. Methods First, the disease-causing mutation was detected by ...Objective To genetically correct a disease-causing point mutation in human induced pluripotent stem cells （iPSCs） derived from a hemophilia B patient. Methods First, the disease-causing mutation was detected by sequencing the encoding area of human coagulation factor IX （F IX） gene. Genomic DNA was extracted from the iPSCs, and the primers were designed to amplify the eight exons of F IX. Next, the point mutation in those iPSCs was genetically corrected using CRISPR/Cas9 technology in the presence of a 129-nucleotide homologous repair template that contained two synonymous mutations. Then, top 8 potential off-target sites were subsequently analyzed using Sanger sequencing. Finally, the corrected clones were differentiated into hepatocyte-like cells, and the secretion of F IX was validated by immunocytochemistry and ELISA assay.Results The cell line bore a missense mutation in the 6th coding exon （c.676 C〉T） of F IX gene. Correction of the point mutation was achieved via CRISPR/Cas9 technology in situ with a high efficacy at about 22% （10/45） and no off-target effects detected in the corrected iPSC clones. F IX secretion, which was further visualized by immunocytochemistry and quantified by ELISA in vitro, reached about 6 ng/ml on day 21 of differentiation procedure. Conclusions Mutations in human disease-specific iPSCs could be precisely corrected by CRISPR/Cas9 technology, and corrected cells still maintained hepatic differentiation capability. Our findings might throw a light on iPSC-based personalized therapies in the clinical application, especially for hemophilia B.展开更多
This study investigates the spatial and temporal variation of fractal dimension and b-value for the eastern part of the Himalaya and adjoining area(26°N–31°N and 87°E–98°E).The analysis is carrie...This study investigates the spatial and temporal variation of fractal dimension and b-value for the eastern part of the Himalaya and adjoining area(26°N–31°N and 87°E–98°E).The analysis is carried out on the earthquake dataset of 1373 events(Mc=4.0)by sliding window technique for the period 1964 to 2020.The region is divided into three sub regions A(87°E–92°E),B(92°E–94°E)and C(94°E–98°E).The b-value computed for the region A comprising eastern Nepal is smaller compared to other two regions which infers the possible high stress and asperities in the region.High spatial fractal dimension(Dc>1.5)and low temporal fractal dimension(Dt<0.31)are computed for the regions.High spatial fractal dimension may indicate that fractures generating earthquakes are approaching a 2D structure and low temporal fractal dimension implies high clustering of earthquake’s epicenters.The b value shows a weak negative correlation with Dc for regions A and C while a weak positive correlation is observed for the region B.Based on b-value and fractal dimension,this study explains the frequency of earthquakes and heterogeneity of the seismogenic structure in this part of the Himalaya.展开更多
[Objective] The study aimed at investigating the influence of enhanced UV-B radiation on photosynthesis of grapevine.[Method] The seedlings of Cabernet sauvignon were treated with different intensities of UV-B radiati...[Objective] The study aimed at investigating the influence of enhanced UV-B radiation on photosynthesis of grapevine.[Method] The seedlings of Cabernet sauvignon were treated with different intensities of UV-B radiation under outdoor conditions,and then the contents of photosynthetic pigments and flavonoids in leaves were determined by measuring the absorbance of leaves extracts at 663,645,470 and 300 nm,respectively.[Result] The content of photosynthetic pigments in the leaves of grapevine obviously increased with time under the treatments of different enhanced UV-B radiation.Compared with the control,the chlorophyll a,chlorophyll b,total chlorophyll and carotenoid were obviously increased by 5%,2%,4% and 3% in the enhanced UV-B radiation treatment of 10.8 μW/cm2（T1）,and in the treatment of 25.6 μW/cm2（T2） the corresponding levels were subsequently increased by 11%,9%,10% and 7% with a significant increase in the content of chlorophyll a.On the other hand,the flavonoids content in the leaves of grapevine were obviously increased by 13%,9% in T1 and T2.[Conclusion] The grapevine has strong adaptability to UV-B radiation,and appropriate enhanced UV-B radiation couldn＇t decrease the photosynthesis of grapevine leaves.展开更多
The phylogeny of the monal pheasants (Lophophorus) and their relationships to some species of the genera Tragopan,Pucrasia and Ithaginis were studied by comparing mitochondrial cytochrome b (cyt b) nucleotide sequence...The phylogeny of the monal pheasants (Lophophorus) and their relationships to some species of the genera Tragopan,Pucrasia and Ithaginis were studied by comparing mitochondrial cytochrome b (cyt b) nucleotide sequences.The molecular phylogenetic trees show that:①the genus Tragopan and the genus Pucrasia share a common ancestor which is the sister taxon of the ancestor of the genus Lophophorus;②the genus Lophophorus had evolved into two branches:One was the Sclaters Monal;the other included the Chinese Monal and the Himalayan Monal.Considering its molecular phylogeny,distribution patterns and morphological evidences,the genus Lophophorus might originate in the Hengduan mountains region of southwestern China.展开更多
The role of bivalent cations and choline in ATP induced apoptosis via P2Z purinoceptor was investigated in human leukemic lymphocytes. In vitro exposure of leukemic lymphocytes with P2Z rec...The role of bivalent cations and choline in ATP induced apoptosis via P2Z purinoceptor was investigated in human leukemic lymphocytes. In vitro exposure of leukemic lymphocytes with P2Z receptors to 1 mmol/L ATP or 0 1 mmol/L benzoylbenzoic ATP(BzATP) for 8 h in the presence of choline, 1 mmol/L Mg 2+ or other bivalent cations, and ATP induced DNA breaks, associated with apoptosis were quantified by TdT assay. We observed that (1) Extracellular Mg 2+ or Ca 2+ stimulated ATP induced DNA fragmentation in a dose dependent manner, and the compatible evidence was provided by the inhibition of ATP induced DNA fragmentation in the present of EGTA or EDTA; (2) ATP induced DNA fragmentation was completely inhibited by 1 mmol/L Zn 2+ ;(3)ATP induced DNA breaks were not affected by Ba 2+ , Sr 2+ , Co 2+ when they were substituted for extracellular Mg 2+ or Ca 2+ ;(4)Choline, an inhibitor of phospholipase D(PLD) stimulated by ATP through P2Z receptor in human lymphocytes, was also a partial inhibitor of ATP induced DNA fragmentation, and the results were confirmed by flow cytometric analysis (FCA); (5)ATP induced DNA fragmentation was completely obliterated when the temperature was lower than 10℃. These results suggest that the endonuclease and PLD may be involved in ATP induced apoptosis in human lymphocytes via P2Z receptor.展开更多
Major histocompatibility complex （MHC） class II B molecules play an important role in the adaptive immune response in fish. Previous study has reported that two highly polymorphic class II B genes, Cyse-DAB and Cyse...Major histocompatibility complex （MHC） class II B molecules play an important role in the adaptive immune response in fish. Previous study has reported that two highly polymorphic class II B genes, Cyse-DAB and Cyse-DBB exist in half-smooth tongue sole （Cynoglossus semilaevis）. In this study, the polymorphism within exon 2 of the class II B genes following bacterial challenge was evaluated. Two hundred C. semilaevis individuals were injected intraperitoneally with Vibrio anguillarum. Muscle tissue from the first 20 dead and 20 of the survivors was collected for genotyping. Sixty alleles from the 40 individuals were isolated, of which 32 belonged to Cyse-DAB and 28 belonged to Cyse-DBB. The rate of dN （non-synonymous substitution） was higher than that of ds （synonymous substitution） in the PBRs （peptide binding residues） of both class I1 B genes. Conversely, the rate of ds was higher than dy in the non-PBRs and the complete exon 2 sequence. Thus, the results suggest that positive selection has occurred in the PBRs and purifying selection in the non-PBRs and exon 2. Thirteen class II B alleles were used to study the association between alleles and resistance to infection. Though not significant, alleles Cyse-DAB＊ 0601, Cyse-DAB ＊ 0706, and Cyse-DBB＊O 101, Cyse-DBB＊ 1301 were only found in surviving individuals and may represent alleles that have resistance against V. anguillarum infection. Alleles Cyse-DAB＊0701 and Cyse-DAB＊1301 were significantly more prevalent in dead individuals than in surviving ones and may represent alleles that are associated with increased susceptibility to V. anguillarum infection.展开更多
Objective To investigate the quantities of bone marrow CD5+ B lymphocytes in the patients with autoimmune hemocytopenia and the relationship between quantities of CD5+ B lymphocytes and clinical or laboratorial parame...Objective To investigate the quantities of bone marrow CD5+ B lymphocytes in the patients with autoimmune hemocytopenia and the relationship between quantities of CD5+ B lymphocytes and clinical or laboratorial parameters. Methods Quantities of CD5+ B lymphocytes in the bone marrow of 14 patients with autoimmune hemolytic anemia (AIHA) or Evans syndrome, 22 immunorelated pancytopenia (IRP) patients, and 10 normal controls were assayed by flow cytometry. The correlation between their clinical or laboratorial parameters and CD5+ B lymphocytes was analyzed. Results The quantity of CD5+ B lymphocytes of AIHA/Evans syndrome (34.64%±19.81%) or IRP patients (35.81%±16.83%) was significantly higher than that of normal controls (12.00%±1.97%, P<0.05). However, there was no significant difference between AIHA/Evans syndrome and IRP patients (P>0.05). In all hemocytopenic patients, the quantity of bone marrow CD5+ B lymphocytes showed significantly negative correlation with serum complement C3 level (r=-0.416, P<0.05). In the patients with AIHA/Evans syndrome, the quantity of bone marrow CD5+ B lymphocytes showed significantly positive correlation with serum indirect bilirubin level (r=1.00, P<0.05). In Evans syndrome patients, the quantity of CD5+ B lymphocytes in bone marrow showed significantly positive correlation with platelet-associated immunoglobulin G (r=0.761, P<0.05) and platelet-associated immunoglobulin M (r=0.925, P<0.05). The quantity of CD5+ B lymphocytes in bone marrow of all hemocytopenic patients showed significantly negative correlation with treatment response (tau-b=-0.289, P<0.05), but had no correlation with colony forming unit-erythroid (r=-0.205, P>0.05) or colony forming unit-granulocyte-macrophage colonies (r=-0.214, P>0.05). Conclusions The quantity of bone marrow CD5+ B lymphocytes in the patients with autoimmune hemocytopenia significantly increases and is correlated with disease severity and clinical response, which suggest that CD5+ B lymphocytes might play an important role in the pathogenesis of autoimmune hemocytopenia.展开更多
Differentially expressed genes(DEGs)between individuals with high(HC)and low(LC)total carotenoid content(TCC)were sampled from a selected line of Pinctada fucata martensii with black shell in the prismatic layer.The e...Differentially expressed genes(DEGs)between individuals with high(HC)and low(LC)total carotenoid content(TCC)were sampled from a selected line of Pinctada fucata martensii with black shell in the prismatic layer.The expression levels of candidate genes were verified by qRT-PCR.Targeted resequencing was used to detect SNPs in a candidate gene,PmSR-BI.The association of TCC with SNPs in PmSR-BI was determined.Results showed that a total of 1025 DEGs were identified between HC and LC.The expression levels of the candidate gene PmSR-BI in HC were higher than those in LC.Seven SNPs in the exon and eight SNPs in the 5′regulatory regions of PmSR-BI were found.Association analysis showed that one SNP in the exon and two SNPs in the 5′regulatory regions of PmSR-BI were significantly associated with the TCC(P<0.05).All SNPs of PmSR-BI were divided into four blocks.CC haplotype in Block 1 and AG haplotype in Block 3 were significantly higher than other haplotypes.These results help elucidate the mechanism underlying carotenoid metabolism and develop marker-assisted breeding design in the species.展开更多
Japanese butterfly ray Gymnura japonica from twinspot butterfly ray G. bimaculata based on a pair of white spots behind eyes or not, which was not reliable. To clarify the taxonomic status of G. japonica and G. bimacu...Japanese butterfly ray Gymnura japonica from twinspot butterfly ray G. bimaculata based on a pair of white spots behind eyes or not, which was not reliable. To clarify the taxonomic status of G. japonica and G. bimaculata, the nucleotide variation between the two butterfly rays was examined using mitochondrial DNA sequence comparisons. Approximately 585 bp of 16S ribosomal RNA （rRNA） and 1,128 bp cytochrome b （cyt b） genes were sequenced from representatives of two butterfly rays species in East China Sea. The results showed that there were the same sequences of 16S rRNA gene between two butterfly rays; six sites were variable among two butterfly rays of cyt b genes, the proportion of polymorphie loci was 0.53%, and two haplotypes were defined which genetic distance was 0.5%. Combined with the morphological character and the analysis of mtDNA sequence indicated that twinspot butterfly ray G. bimaculata was a synonym of Japanese butterfly ray G. japonica.展开更多
Classifying single-trial electroencephalogram(EEG)based motor imagery(MI)tasks is extensively used to control brain-computer interface(BCI)applications,as a communication bridge between humans and computers.However,th...Classifying single-trial electroencephalogram(EEG)based motor imagery(MI)tasks is extensively used to control brain-computer interface(BCI)applications,as a communication bridge between humans and computers.However,the low signal-to-noise ratio and individual differences of EEG can affect the classification results negatively.In this paper,we propose an improved common spatial pattern(B-CSP)method to extract features for alleviating these adverse effects.First,for different subjects,the method of Bhattacharyya distance is used to select the optimal frequency band of each electrode including strong event-related desynchronization(ERD)and event-related synchronization(ERS)patterns;then the signals of the optimal frequency band are decomposed into spatial patterns,and the features that can describe the maximum differences of two classes of MI are extracted from the EEG data.The proposed method is applied to the public data set and experimental data set to extract features which are input into a back propagation neural network(BPNN)classifier to classify single-trial MI EEG.Another two conventional feature extraction methods,original common spatial pattern(CSP)and autoregressive(AR),are used for comparison.An improved classification performance for both data sets(public data set:91.25%±1.77%for left hand vs.foot and84.50%±5.42%for left hand vs.right hand;experimental data set:90.43%±4.26%for left hand vs.foot)verifies the advantages of the B-CSP method over conventional methods.The results demonstrate that our proposed B-CSP method can classify EEG-based MI tasks effectively,and this study provides practical and theoretical approaches to BCI applications.展开更多
基金Supported by the National Science and Technology Major Project(2011ZX09102-010-04)
文摘Objective To genetically correct a disease-causing point mutation in human induced pluripotent stem cells （iPSCs） derived from a hemophilia B patient. Methods First, the disease-causing mutation was detected by sequencing the encoding area of human coagulation factor IX （F IX） gene. Genomic DNA was extracted from the iPSCs, and the primers were designed to amplify the eight exons of F IX. Next, the point mutation in those iPSCs was genetically corrected using CRISPR/Cas9 technology in the presence of a 129-nucleotide homologous repair template that contained two synonymous mutations. Then, top 8 potential off-target sites were subsequently analyzed using Sanger sequencing. Finally, the corrected clones were differentiated into hepatocyte-like cells, and the secretion of F IX was validated by immunocytochemistry and ELISA assay.Results The cell line bore a missense mutation in the 6th coding exon （c.676 C〉T） of F IX gene. Correction of the point mutation was achieved via CRISPR/Cas9 technology in situ with a high efficacy at about 22% （10/45） and no off-target effects detected in the corrected iPSC clones. F IX secretion, which was further visualized by immunocytochemistry and quantified by ELISA in vitro, reached about 6 ng/ml on day 21 of differentiation procedure. Conclusions Mutations in human disease-specific iPSCs could be precisely corrected by CRISPR/Cas9 technology, and corrected cells still maintained hepatic differentiation capability. Our findings might throw a light on iPSC-based personalized therapies in the clinical application, especially for hemophilia B.
基金University Grants Commission(UGC),Nepal for providing financial support。
文摘This study investigates the spatial and temporal variation of fractal dimension and b-value for the eastern part of the Himalaya and adjoining area(26°N–31°N and 87°E–98°E).The analysis is carried out on the earthquake dataset of 1373 events(Mc=4.0)by sliding window technique for the period 1964 to 2020.The region is divided into three sub regions A(87°E–92°E),B(92°E–94°E)and C(94°E–98°E).The b-value computed for the region A comprising eastern Nepal is smaller compared to other two regions which infers the possible high stress and asperities in the region.High spatial fractal dimension(Dc>1.5)and low temporal fractal dimension(Dt<0.31)are computed for the regions.High spatial fractal dimension may indicate that fractures generating earthquakes are approaching a 2D structure and low temporal fractal dimension implies high clustering of earthquake’s epicenters.The b value shows a weak negative correlation with Dc for regions A and C while a weak positive correlation is observed for the region B.Based on b-value and fractal dimension,this study explains the frequency of earthquakes and heterogeneity of the seismogenic structure in this part of the Himalaya.
文摘[Objective] The study aimed at investigating the influence of enhanced UV-B radiation on photosynthesis of grapevine.[Method] The seedlings of Cabernet sauvignon were treated with different intensities of UV-B radiation under outdoor conditions,and then the contents of photosynthetic pigments and flavonoids in leaves were determined by measuring the absorbance of leaves extracts at 663,645,470 and 300 nm,respectively.[Result] The content of photosynthetic pigments in the leaves of grapevine obviously increased with time under the treatments of different enhanced UV-B radiation.Compared with the control,the chlorophyll a,chlorophyll b,total chlorophyll and carotenoid were obviously increased by 5%,2%,4% and 3% in the enhanced UV-B radiation treatment of 10.8 μW/cm2（T1）,and in the treatment of 25.6 μW/cm2（T2） the corresponding levels were subsequently increased by 11%,9%,10% and 7% with a significant increase in the content of chlorophyll a.On the other hand,the flavonoids content in the leaves of grapevine were obviously increased by 13%,9% in T1 and T2.[Conclusion] The grapevine has strong adaptability to UV-B radiation,and appropriate enhanced UV-B radiation couldn＇t decrease the photosynthesis of grapevine leaves.
文摘The phylogeny of the monal pheasants (Lophophorus) and their relationships to some species of the genera Tragopan,Pucrasia and Ithaginis were studied by comparing mitochondrial cytochrome b (cyt b) nucleotide sequences.The molecular phylogenetic trees show that:①the genus Tragopan and the genus Pucrasia share a common ancestor which is the sister taxon of the ancestor of the genus Lophophorus;②the genus Lophophorus had evolved into two branches:One was the Sclaters Monal;the other included the Chinese Monal and the Himalayan Monal.Considering its molecular phylogeny,distribution patterns and morphological evidences,the genus Lophophorus might originate in the Hengduan mountains region of southwestern China.
文摘The role of bivalent cations and choline in ATP induced apoptosis via P2Z purinoceptor was investigated in human leukemic lymphocytes. In vitro exposure of leukemic lymphocytes with P2Z receptors to 1 mmol/L ATP or 0 1 mmol/L benzoylbenzoic ATP(BzATP) for 8 h in the presence of choline, 1 mmol/L Mg 2+ or other bivalent cations, and ATP induced DNA breaks, associated with apoptosis were quantified by TdT assay. We observed that (1) Extracellular Mg 2+ or Ca 2+ stimulated ATP induced DNA fragmentation in a dose dependent manner, and the compatible evidence was provided by the inhibition of ATP induced DNA fragmentation in the present of EGTA or EDTA; (2) ATP induced DNA fragmentation was completely inhibited by 1 mmol/L Zn 2+ ;(3)ATP induced DNA breaks were not affected by Ba 2+ , Sr 2+ , Co 2+ when they were substituted for extracellular Mg 2+ or Ca 2+ ;(4)Choline, an inhibitor of phospholipase D(PLD) stimulated by ATP through P2Z receptor in human lymphocytes, was also a partial inhibitor of ATP induced DNA fragmentation, and the results were confirmed by flow cytometric analysis (FCA); (5)ATP induced DNA fragmentation was completely obliterated when the temperature was lower than 10℃. These results suggest that the endonuclease and PLD may be involved in ATP induced apoptosis in human lymphocytes via P2Z receptor.
基金Supported by the National Natural Science Foundation of China(No.30901098)
文摘Major histocompatibility complex （MHC） class II B molecules play an important role in the adaptive immune response in fish. Previous study has reported that two highly polymorphic class II B genes, Cyse-DAB and Cyse-DBB exist in half-smooth tongue sole （Cynoglossus semilaevis）. In this study, the polymorphism within exon 2 of the class II B genes following bacterial challenge was evaluated. Two hundred C. semilaevis individuals were injected intraperitoneally with Vibrio anguillarum. Muscle tissue from the first 20 dead and 20 of the survivors was collected for genotyping. Sixty alleles from the 40 individuals were isolated, of which 32 belonged to Cyse-DAB and 28 belonged to Cyse-DBB. The rate of dN （non-synonymous substitution） was higher than that of ds （synonymous substitution） in the PBRs （peptide binding residues） of both class I1 B genes. Conversely, the rate of ds was higher than dy in the non-PBRs and the complete exon 2 sequence. Thus, the results suggest that positive selection has occurred in the PBRs and purifying selection in the non-PBRs and exon 2. Thirteen class II B alleles were used to study the association between alleles and resistance to infection. Though not significant, alleles Cyse-DAB＊ 0601, Cyse-DAB ＊ 0706, and Cyse-DBB＊O 101, Cyse-DBB＊ 1301 were only found in surviving individuals and may represent alleles that have resistance against V. anguillarum infection. Alleles Cyse-DAB＊0701 and Cyse-DAB＊1301 were significantly more prevalent in dead individuals than in surviving ones and may represent alleles that are associated with increased susceptibility to V. anguillarum infection.
文摘Objective To investigate the quantities of bone marrow CD5+ B lymphocytes in the patients with autoimmune hemocytopenia and the relationship between quantities of CD5+ B lymphocytes and clinical or laboratorial parameters. Methods Quantities of CD5+ B lymphocytes in the bone marrow of 14 patients with autoimmune hemolytic anemia (AIHA) or Evans syndrome, 22 immunorelated pancytopenia (IRP) patients, and 10 normal controls were assayed by flow cytometry. The correlation between their clinical or laboratorial parameters and CD5+ B lymphocytes was analyzed. Results The quantity of CD5+ B lymphocytes of AIHA/Evans syndrome (34.64%±19.81%) or IRP patients (35.81%±16.83%) was significantly higher than that of normal controls (12.00%±1.97%, P<0.05). However, there was no significant difference between AIHA/Evans syndrome and IRP patients (P>0.05). In all hemocytopenic patients, the quantity of bone marrow CD5+ B lymphocytes showed significantly negative correlation with serum complement C3 level (r=-0.416, P<0.05). In the patients with AIHA/Evans syndrome, the quantity of bone marrow CD5+ B lymphocytes showed significantly positive correlation with serum indirect bilirubin level (r=1.00, P<0.05). In Evans syndrome patients, the quantity of CD5+ B lymphocytes in bone marrow showed significantly positive correlation with platelet-associated immunoglobulin G (r=0.761, P<0.05) and platelet-associated immunoglobulin M (r=0.925, P<0.05). The quantity of CD5+ B lymphocytes in bone marrow of all hemocytopenic patients showed significantly negative correlation with treatment response (tau-b=-0.289, P<0.05), but had no correlation with colony forming unit-erythroid (r=-0.205, P>0.05) or colony forming unit-granulocyte-macrophage colonies (r=-0.214, P>0.05). Conclusions The quantity of bone marrow CD5+ B lymphocytes in the patients with autoimmune hemocytopenia significantly increases and is correlated with disease severity and clinical response, which suggest that CD5+ B lymphocytes might play an important role in the pathogenesis of autoimmune hemocytopenia.
基金The research was financially supported by Science and Technology Program of Guangdong Province(Grant No.2021B0202020003,and 2022A1515010030)National Natural Science Foundation of China(Grant No.32102817)+2 种基金Department of Education of Guangdong Province(Grant No.2019KQNCX043,2020ZDZX1045 and 2021KCXTD026)Special promotion of fishery science and technology of Ocean and Fisheries Bureau of Guangdong Province(Grant No.B201601-Z09)the earmarked fund for CARS-49.
文摘Differentially expressed genes(DEGs)between individuals with high(HC)and low(LC)total carotenoid content(TCC)were sampled from a selected line of Pinctada fucata martensii with black shell in the prismatic layer.The expression levels of candidate genes were verified by qRT-PCR.Targeted resequencing was used to detect SNPs in a candidate gene,PmSR-BI.The association of TCC with SNPs in PmSR-BI was determined.Results showed that a total of 1025 DEGs were identified between HC and LC.The expression levels of the candidate gene PmSR-BI in HC were higher than those in LC.Seven SNPs in the exon and eight SNPs in the 5′regulatory regions of PmSR-BI were found.Association analysis showed that one SNP in the exon and two SNPs in the 5′regulatory regions of PmSR-BI were significantly associated with the TCC(P<0.05).All SNPs of PmSR-BI were divided into four blocks.CC haplotype in Block 1 and AG haplotype in Block 3 were significantly higher than other haplotypes.These results help elucidate the mechanism underlying carotenoid metabolism and develop marker-assisted breeding design in the species.
文摘Japanese butterfly ray Gymnura japonica from twinspot butterfly ray G. bimaculata based on a pair of white spots behind eyes or not, which was not reliable. To clarify the taxonomic status of G. japonica and G. bimaculata, the nucleotide variation between the two butterfly rays was examined using mitochondrial DNA sequence comparisons. Approximately 585 bp of 16S ribosomal RNA （rRNA） and 1,128 bp cytochrome b （cyt b） genes were sequenced from representatives of two butterfly rays species in East China Sea. The results showed that there were the same sequences of 16S rRNA gene between two butterfly rays; six sites were variable among two butterfly rays of cyt b genes, the proportion of polymorphie loci was 0.53%, and two haplotypes were defined which genetic distance was 0.5%. Combined with the morphological character and the analysis of mtDNA sequence indicated that twinspot butterfly ray G. bimaculata was a synonym of Japanese butterfly ray G. japonica.
基金Project supported by the National Natural Science Foundation of China(Nos.61702454 and 61772468)the MOE Project of Humanities and Social Sciences,China(No.17YJC870018)+1 种基金the Fundamental Research Funds for the Provincial Universities of Zhejiang Province,China(No.GB201901006)the Philosophy and Social Science Planning Fund Project of Zhejiang Province,China(No.20NDQN260YB)
文摘Classifying single-trial electroencephalogram(EEG)based motor imagery(MI)tasks is extensively used to control brain-computer interface(BCI)applications,as a communication bridge between humans and computers.However,the low signal-to-noise ratio and individual differences of EEG can affect the classification results negatively.In this paper,we propose an improved common spatial pattern(B-CSP)method to extract features for alleviating these adverse effects.First,for different subjects,the method of Bhattacharyya distance is used to select the optimal frequency band of each electrode including strong event-related desynchronization(ERD)and event-related synchronization(ERS)patterns;then the signals of the optimal frequency band are decomposed into spatial patterns,and the features that can describe the maximum differences of two classes of MI are extracted from the EEG data.The proposed method is applied to the public data set and experimental data set to extract features which are input into a back propagation neural network(BPNN)classifier to classify single-trial MI EEG.Another two conventional feature extraction methods,original common spatial pattern(CSP)and autoregressive(AR),are used for comparison.An improved classification performance for both data sets(public data set:91.25%±1.77%for left hand vs.foot and84.50%±5.42%for left hand vs.right hand;experimental data set:90.43%±4.26%for left hand vs.foot)verifies the advantages of the B-CSP method over conventional methods.The results demonstrate that our proposed B-CSP method can classify EEG-based MI tasks effectively,and this study provides practical and theoretical approaches to BCI applications.
