A combined DPA1~DPB1 amino acid epitope is the primary unit of selection on the HLA-DP heterodimer

Here, we present results for DPA1 and DPB1 four-digit allele-level typing in a large (n = 5,944) sample of unrelated European American stem cell donors previously characterized for other class I and class II loci. Examination of genetic data for both chains of the DP heterodimer in the largest cohort to date, at the amino acid epitope, allele, genotype, and haplotype level, allows new insights into the functional units of selection and association for the DP heterodimer. The data in this study suggest that for the DPA1-DPB1 heterodimer, the unit of selection is the combined amino acid epitope contributed by both the DPA1 and DPB1 genes, rather than the allele, and that patterns of LD are driven primarily by dimer stability and conformation of the P1 pocket. This may help explain the differential pattern of allele frequency distribution observed for this locus relative to the other class II loci. These findings further support the notion that allele-level associations in disease and transplantation may not be the most important unit of analysis, and that they should be considered instead in the molecular context.     

Six New Acylphloroglucinols from Dryopteris championii

Six new acylphloroglucinols ( 1  –  6 ) were isolated from Dryopteris championii. Their structures were established on the basis of extensive analysis of spectroscopic data and comparison with reported data. The antibacterial activities of the isolates were evaluated against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, and Dickeya zeae.     

Proteogenomic analysis reveals alternative splicing and translation as part of the abscisic acid response in Arabidopsis seedlings

In eukaryotes, mechanisms such as alternative splicing (AS) and alternative translation initiation (ATI) contribute to organismal protein diversity. Specifically, splicing factors play crucial roles in responses to environment and development cues; however, the underlying mechanisms are not well investigated in plants. Here, we report the parallel employment of short‐read RNA sequencing, single molecule long‐read sequencing and proteomic identification to unravel AS isoforms and previously unannotated proteins in response to abscisic acid (ABA) treatment. Combining the data from the two sequencing methods, approximately 83.4% of intron‐containing genes were alternatively spliced. Two AS types, which are referred to as alternative first exon (AFE) and alternative last exon (ALE), were more abundant than intron retention (IR); however, by contrast to AS events detected under normal conditions, differentially expressed AS isoforms were more likely to be translated. ABA extensively affects the AS pattern, indicated by the increasing number of non‐conventional splicing sites. This work also identified thousands of unannotated peptides and proteins by ATI based on mass spectrometry and a virtual peptide library deduced from both strands of coding regions within the Arabidopsis genome. The results enhance our understanding of AS and alternative translation mechanisms under normal conditions, and in response to ABA treatment.     

牛樟芝非核糖体多肽合成酶基因(ＡcNRPS)的克隆与鉴定

胶霉毒素属于真菌天然次生代谢产物epipolythiodioxopiperazine (ETP)家族,具有免疫抑制剂、抗真菌等多种生物活性,是由非核糖体多肽合成酶(NRPSs)催化合成。从牛樟芝(Antrodia camphorata)基因组中挖掘出非核糖体多肽合成酶基因(AcNRPS,NCBI登录号为KX430967),克隆获取其全长cDNA,并对其进行生物信息学分析和表达谱分析。结果显示AcNRPS基因cDNA全长6 687 bp;与其DNA序列比对发现AcNRPS基因含有12 个内含子;其开放阅读框编码2 229 个氨基酸残基,BLAST比对发现其含有2 个A-C-T结构域,底物需2个氨基酸;系统发育树结果显示AcNRPS与其他合成产物为胶霉毒素的NRPS基因聚为一类,其可合成胶霉毒素类化合物;表达谱分析显示,以葡萄糖和土豆蛋白胨作为碳、氮源的培养基能够有效促进牛樟芝NRPS基因的表达。     

石山稀有濒危植物迁地保护适应性研究(简报)

报道了青檀、桂林紫薇、东京桐、掌叶木、任木、小花异裂菊和海南椴 7种石山稀有濒危植物迁移到酸性红壤上的表现     

改善植物大规模组织培养条件的研究进展

植物组织培养技术具有巨大的应用价值,传统组织培养存在许多缺点,许多学者从培养基、培养容器、环境条件(光照、气体等)进行了研究和改善,取得了一定的成效。综述了这些方面的研究进展。     

多荚草皂甙D和E的结构

从石竹科植物多荚草（Polycarpon prostratum(Forssk)Aschers.et Schwein.ex Aschers）的全草中分离得到了2个新的柴胡皂甙类化合物：prostratoside D和E。它们的结构过波谱方法分别鉴定为3－O－{β－D－xylpoyranosy-(1→2）－β－D－glucopyransoyl-(1→4）－[β－D－glucopyranosyl-（1→2）]-α－L－arabinopyranoside}－saikogeninD和3-O-{β－D－xylpoyranosy-(1→2）－β－D－glucopyransoyl-(1→4）－[β－D－glucopyranosyl-（1→2）]-α－L－arabinopyranoside}－saikogeninG。