Mazur spaces, which are locally convex spaces and every sequentially continuous linear functional over them is continuous,are characterized. The following results are obtained, if (X, T) is a locally convex space, the...Mazur spaces, which are locally convex spaces and every sequentially continuous linear functional over them is continuous,are characterized. The following results are obtained, if (X, T) is a locally convex space, then the followings are equivalent: 1) (X, T) is a Mazur space; 2) T + (the largest locally convex topology with the same convergent sequence as T) is a compatible topology with T; 3) every sequentially open half-space in (X, T) is open. The relation between Mazur spaces and C-sequential spaces is discussed.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
Platichthys stellatus is an economically important marine bony fish species that is cultured in China on a large scale.However,very little is known about its immune-related genes.In this study,the transcriptome of the...Platichthys stellatus is an economically important marine bony fish species that is cultured in China on a large scale.However,very little is known about its immune-related genes.In this study,the transcriptome of the immune organs ofP.stellatus that were intraperitoneally challenged with the pathogen Edwardsiella ictaluri JCM1680 is analyzed.Total RNA from four tissues(spleen,kidney,liver,and intestine) was mixed equally and then sequenced on an Illumina HiSeq 2000 platform.Overall,28 465 813 quality reads were generated and assembled into 43 061 unigenes.Similarity searches against public protein sequence databases were used to annotate 28 291 unigenes(65.7%of the total),368 of which were associated with immunoregulation,including 188 related to immunity response.Additionally,the transcript levels of immunity response unigenes annotated as related to tumor necrosis factor(TNF),TNF receptor,chemokine,major histocompatibility complex,and interleukin-6 were investigated in the different tissues of normal and infected P.stellatus by real-time quantitative PCR.The results confirmed that the unigenes identified in the transcriptome database were indeed expressed and up-regulated in infected P.stellatus.To our knowledge,this is the first report of the sequencing and analysis of the transcriptome of P.stellatus.These findings provide insights into the transcriptomics and immunogenetics of bony fish.展开更多
自然杀伤细胞2族成员D(natural killer group 2 member D,NKG2D)是由NK细胞表达的一种免疫受体,可识别靶细胞表面上的人类主要组织相容性复合体Ⅰ类多肽相关序列(major histocompatibility complex Class I polypetide-related chain,MI...自然杀伤细胞2族成员D(natural killer group 2 member D,NKG2D)是由NK细胞表达的一种免疫受体,可识别靶细胞表面上的人类主要组织相容性复合体Ⅰ类多肽相关序列(major histocompatibility complex Class I polypetide-related chain,MIC)A/B。NKG2D与MICA/B的相互作用,在病毒感染和癌症的免疫监视中发挥重要作用。该文通过膜结合型MICB下调、分泌型MICB增多及MICB基因多态性三部分对MICB/NKG2D信号通路在免疫逃逸中的研究进展进行综述。展开更多
Major histocompatibility complex （MHC） is a family of highly polymorphic genes activating adaptive immunity in vertebrates. However, the underlying mecha- nism of MHC evolution is still not fully understood. In this...Major histocompatibility complex （MHC） is a family of highly polymorphic genes activating adaptive immunity in vertebrates. However, the underlying mecha- nism of MHC evolution is still not fully understood. In this study, we investigated genetic variation of three classical MHC class I genes in the giant panda （Ailuropoda mela- noleuca） and tested for selection effect and recombination event across exonic and intronic sequences to understand maintenance mechanism of polymorphism at Aime-MHC class I genes. In total, we isolated 21 MHC class I haplotypes （exon 2-intron 2-exon 3） from 46 captive giant pandas, of which eight were for Aime-C, seven for Aime-I and six for Aime-L; however, we only identified six unique sequences from these haplotypes. The subsequent maximum-likeli- hood and Chi-square analyses both detected evidence of recombination acting on the 21 haplotypes. These results indicate that the giant panda still retains a relatively high adaptive variation at Aime-MHC-I genes, and that the intronic segments have been homogenized along evolu- tionary time by recombination and subsequent genetic drift.We calculated nucleotide substitution rates of the antigen- binding regions （exons 2 and 3） and the noncoding intron 2, and found two pieces of evidence supporting the presence of balancing selection in the giant panda： an excess of nonsynonymous over synonymous substitutions at the antigen-binding sites, and an obviously higher synonymous substitutions in the exons than nucleotide substitutions in the intron. Thus, this study reveals that balancing selection and recombination together shape the diversity pattern at Aime- MHC-I loci of the giant panda.展开更多
文摘Mazur spaces, which are locally convex spaces and every sequentially continuous linear functional over them is continuous,are characterized. The following results are obtained, if (X, T) is a locally convex space, then the followings are equivalent: 1) (X, T) is a Mazur space; 2) T + (the largest locally convex topology with the same convergent sequence as T) is a compatible topology with T; 3) every sequentially open half-space in (X, T) is open. The relation between Mazur spaces and C-sequential spaces is discussed.
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.
基金Supported by the National High Technology Research and Development Program of China(863 Program)(Nos.2012AA10A413,2012AA10A408)the National Marine Public Welfare Research Project(No.201205025)
文摘Platichthys stellatus is an economically important marine bony fish species that is cultured in China on a large scale.However,very little is known about its immune-related genes.In this study,the transcriptome of the immune organs ofP.stellatus that were intraperitoneally challenged with the pathogen Edwardsiella ictaluri JCM1680 is analyzed.Total RNA from four tissues(spleen,kidney,liver,and intestine) was mixed equally and then sequenced on an Illumina HiSeq 2000 platform.Overall,28 465 813 quality reads were generated and assembled into 43 061 unigenes.Similarity searches against public protein sequence databases were used to annotate 28 291 unigenes(65.7%of the total),368 of which were associated with immunoregulation,including 188 related to immunity response.Additionally,the transcript levels of immunity response unigenes annotated as related to tumor necrosis factor(TNF),TNF receptor,chemokine,major histocompatibility complex,and interleukin-6 were investigated in the different tissues of normal and infected P.stellatus by real-time quantitative PCR.The results confirmed that the unigenes identified in the transcriptome database were indeed expressed and up-regulated in infected P.stellatus.To our knowledge,this is the first report of the sequencing and analysis of the transcriptome of P.stellatus.These findings provide insights into the transcriptomics and immunogenetics of bony fish.
文摘自然杀伤细胞2族成员D(natural killer group 2 member D,NKG2D)是由NK细胞表达的一种免疫受体,可识别靶细胞表面上的人类主要组织相容性复合体Ⅰ类多肽相关序列(major histocompatibility complex Class I polypetide-related chain,MIC)A/B。NKG2D与MICA/B的相互作用,在病毒感染和癌症的免疫监视中发挥重要作用。该文通过膜结合型MICB下调、分泌型MICB增多及MICB基因多态性三部分对MICB/NKG2D信号通路在免疫逃逸中的研究进展进行综述。
基金supported by a special grant(SG1411)for the giant panda from the State Forestry Administration of China
文摘Major histocompatibility complex （MHC） is a family of highly polymorphic genes activating adaptive immunity in vertebrates. However, the underlying mecha- nism of MHC evolution is still not fully understood. In this study, we investigated genetic variation of three classical MHC class I genes in the giant panda （Ailuropoda mela- noleuca） and tested for selection effect and recombination event across exonic and intronic sequences to understand maintenance mechanism of polymorphism at Aime-MHC class I genes. In total, we isolated 21 MHC class I haplotypes （exon 2-intron 2-exon 3） from 46 captive giant pandas, of which eight were for Aime-C, seven for Aime-I and six for Aime-L; however, we only identified six unique sequences from these haplotypes. The subsequent maximum-likeli- hood and Chi-square analyses both detected evidence of recombination acting on the 21 haplotypes. These results indicate that the giant panda still retains a relatively high adaptive variation at Aime-MHC-I genes, and that the intronic segments have been homogenized along evolu- tionary time by recombination and subsequent genetic drift.We calculated nucleotide substitution rates of the antigen- binding regions （exons 2 and 3） and the noncoding intron 2, and found two pieces of evidence supporting the presence of balancing selection in the giant panda： an excess of nonsynonymous over synonymous substitutions at the antigen-binding sites, and an obviously higher synonymous substitutions in the exons than nucleotide substitutions in the intron. Thus, this study reveals that balancing selection and recombination together shape the diversity pattern at Aime- MHC-I loci of the giant panda.
