Genetic characterisation and fine mapping of a chlorophyll-deficient mutant (BnaC.ygl) in Brassica napus

A chlorophyll-deficient mutant with yellow-green leaves of Brassica napus was obtained by treatment with the chemical mutagen ethyl methanesulfonate. Compared with the wild type at seedling stage, the mutant displayed decreased total chlorophyll content, less granal stacks and granal membranes. Genetic analysis confirmed that the mutant phenotype was controlled by a recessive gene, which was designated as BnaC.ygl. Mapping of the gene was subsequently conducted in two populations with yellow-green leaves (population IBC₈ and IIBC₄, which comprised 3,472 and 5,288 individuals, respectively). Analysis on the public simple sequence repeat markers (SSR) showed that four SSR markers linked to BnaC.YGL gene displayed polymorphism. Based on the information of these SSR markers, the BnaC.YGL gene was mapped to the linkage group N17. From a survey of amplified fragment length polymorphism (AFLP), 15 of 47 AFLP markers were successfully converted into sequence characterised amplified region (SCAR) markers. BnY5 and CB10534, the closest flanking markers, were 0.32 and 0.03 cM away from the BnaC.YGL gene, respectively. And in the two populations, 18 makers cosegregated with BnaC.YGL. BLAST analysis revealed that the sequences of the makers displayed highly conserved homology with C06 of B. oleracea. The collinearity of makers to makers on N17 and on C06 showed that there might be an inversion occurring on the N17 group. These results are expected to accelerate the process of cloning the BnaC.YGL gene and facilitate the understanding of the biological processes of chloroplast development in Brassica napus.     

线虫全基因组RNAi筛选确定CAB-1为特异性调节致密核心囊泡分泌的因子

内分泌细胞和神经细胞通过释放激素和神经肽类物质来响应外界刺激,而这些物质的分泌,都是通过致密核心囊泡(dense core vesicle,DCV)来实现的.但是,现阶段关于DCV的生成、转运、释放的机制很大程度上是不清楚的.在本研究中,我们将线虫的排便行为和肠道分泌联系起来,并以此表型进行全基因组RNAi筛选,寻找调节DCV的新基因.我们成功筛选到了一些在肠道调节DCV生成或释放的基因.其中,CAB-1被确认为特异性调节DCV分泌的重要因子.在肠道中,cab-1突变会降低肠道DCV内容物的分泌,而在神经系统中,CAB-1的缺失也会导致DCV的标识物堆积在突触前,而突触囊泡(synaptic vesicle,SV)不受影响.     

Genetic assessment of safflower (Carthamus tinctorius L.) collection with microsatellite markers acquired via pyrosequencing method

A genetic evaluation of safflower germplasm collections derived from different geographical regions and countries will provide useful information for sustainable conservation and the utilization of genetic diversity. However, the molecular marker information is limited for evaluation of genetic diversity of safflower germplasm. In this study, we acquired 509 putative genomic SSR markers for sufficient genome coverage using next‐generation sequencing methods and characterized thirty polymorphic SSRs in safflower collection composed of 100 diverse accessions. The average allele number and expected heterozygosity were 2.8 and 0.386, respectively. Analysis of population structure and phylogeny based on thirty SSR profiles revealed genetic admixture between geographical regions contrary to genetic clustering. However, the accessions from Korea were genetically conserved in distinctive groups in contrast to other safflower gene pool. In conclusion, these new genomic SSRs will facilitate valuable studies to clarify genetic relationships as well as conduct population structure analyses, genetic map construction and association analysis for safflower.     

泌尿外科住院患者泌尿系感染病原菌分布及其耐药性分析

了解泌尿外科住院患者泌尿系感染病原菌的分布及其对常用抗菌药物的耐药情况。对泌尿外科泌尿系感染住院患者的消毒中段尿培养结果进行回顾性分析,尿培养菌株的鉴定、药敏分析和统计分析采用VITEK2全自动微生物仪。3 a中泌尿外科泌尿系感染住院患者共分离到细菌1 233株,其中革兰阴性杆菌772株,占62.61%,革兰阳性球菌353株,占28.63%,真菌82株,占6.65%。菌株数居前5位的细菌依次为:大肠埃希菌、肠球菌属、洋葱伯克霍尔德菌、假丝酵母菌属和变形杆菌。分离大肠埃希菌产ESBLs率为66.18%,粪肠球菌中未发现VRE菌株,屎肠球菌VRE为0.8%。未发现对美洛培南耐药的大肠埃希菌,对肠埃希菌耐药率在10%以下的有亚胺培南、阿米卡星、哌拉西林/他唑巴坦和呋喃妥因。洋葱伯克霍尔德菌和铜绿假单胞菌对所监测的抗菌药物均有不同程度的耐药。未发现对万古霉素、替考拉宁及氨苄西林耐药的粪肠球菌。泌尿系感染的病原菌以大肠埃希菌和肠球菌为主,非发酵革兰阴性杆菌及假丝酵母菌所占比例超过20%,不容忽视,病原菌的耐药率较高,临床医生应根据尿培养和药敏试验结果合理使用抗菌药物。     

Cancer incidence and mortality in people aged less than 75 years: Changes in Australia over the period 1987–2007

BackgroundAustralia has one of the highest rates of cancer incidence worldwide and, despite improving survival, cancer continues to be a major public health problem. Our aim was to provide simple summary measures of changes in cancer mortality and incidence in Australia so that progress and areas for improvement in cancer control can be identified.MethodsWe used national data on cancer deaths and newly registered cancer cases and compared expected and observed numbers of deaths and cases diagnosed in 2007. The expected numbers were obtained by applying 1987 age–sex specific rates (average of 1986–1988) directly to the 2007 population. The observed numbers of deaths and incident cases were calculated for 2007 (average of 2006–2008). We limited the analyses to people aged less than 75 years.ResultsThere was a 28% fall in cancer mortality (7827 fewer deaths in 2007 vs. 1987) and a 21% increase in new cancer diagnoses (13,012 more diagnosed cases in 2007). The greatest reductions in deaths were for cancers of the lung in males (?2259), bowel (?1797), breast (?773) and stomach (?577). Other notable falls were for cancers of the prostate (?295), cervix (?242) and non-Hodgkin lymphoma (?240). Only small or no changes occurred in mortality for cancers of the lung (female only), pancreas, brain and related, oesophagus and thyroid, with an increase in liver cancer (267). Cancer types that showed the greatest increase in incident cases were cancers of the prostate (10,245), breast (2736), other cancers (1353), melanoma (1138) and thyroid (1107), while falls were seen for cancers of the lung (?1705), bladder (?1110) and unknown primary (?904).ConclusionsThe reduction in mortality indicates that prevention strategies, improvements in cancer treatment, and screening programmes have made significant contributions to cancer control in Australia since 1987. The rise in incidence is partly due to diagnoses being brought forward by technological improvements and increased coverage of screening and early diagnostic testing.     

Association of Cerebral Networks in Resting State with Sexual Preference of Homosexual Men: A Study of Regional Homogeneity and Functional Connectivity

Recent imaging studies have shown that brain morphology and neural activity during sexual arousal differ between homosexual and heterosexual men. However, functional differences in neural networks at the resting state is unknown. The study is to characterize the association of homosexual preference with measures of regional homogeneity and functional connectivity in the resting state. Participants were 26 healthy homosexual men and 26 age-matched healthy heterosexual men in whom we collected echo planar magnetic resonance imaging data in the resting state. The sexual orientation was evaluated using the Kinsey Scale. We first assessed group differences in regional homogeneity and then, taking the identified differences as seed regions, we compared groups in measures of functional connectivity from those seeds. The behavioral significances of the differences in regional homogeneity and functional connectivity were assessed by examining their associations with Kinsey Scores. Homosexual participants showed significantly reduced regional homogeneity in the left inferior occipital gyrus, right middle occipital gyrus, right superior occipital gyrus, left cuneus, right precuneus, and increased regional homogeneity in rectal gyrus, bilateral midbrain, and left temporal lobe. Regional homogeneity correlated positively with Kinsey scores in the left inferior occipital gyrus. The homosexual group also showed reduced functional connectivity between left middle temporal gyrus, left supra-marginal gyrus, right cuneus and the seed region, i.e. left inferior occipital gyrus. Additionly, the connection between the left inferior occipital gyrus and right thalamus correlated positively with Kinsey scores. These differences in regional homogeneity and functional connectivity may contribute to a better understanding of the neural basis of male sexual orientation.     

Candidate target genes for the Saccharomyces cerevisiae transcription factor, Yap2

In Saccharomyces cerevisiae, the Yap family of basic leucine zipper (bZip) proteins contains eight members. The Yap family proteins are implicated in a variety of stress responses; among these proteins, Yap1 acts as a major regulator of oxidative stress responses. However, the functional roles of the remaining Yap family members are poorly understood. To elucidate the function of Yap2, we mined candidate target genes of Yap2 by proteomic analysis. Among the identified genes, FRM2 was previously identified as a target gene of Yap2, which confirmed the validity of our screening method. YNL134C and YDL124W were also identified as candidate Yap2 target genes. These genes were upregulated in strains overexpressing Yap2 and possess Yap2 target sequences in their promoter regions. Furthermore, chromatin immunoprecipitation assays showed that YNL134C and YDL124W have Yap2 binding motif. These data will help to elucidate the functional role of Yap2.     

枫香叶片变色期全长转录组测序及分析

枫香因其树形优美,入秋后叶色红艳或橙黄,极具观赏价值,是优良的景观生态树种。为了解枫香叶片变色及其次级代谢过程的遗传基础,该文以枫香5个叶片变色期叶片混合样品为材料,利用单分子实时测序技术(PacBio平台)对其进行全长转录组测序。结果表明:(1)全长转录组测序共获得41.04 Gb的高质量数据,从中鉴定出全长非嵌合序列563 180条,通过聚类和去冗余,获得27 269条高质量全长转录本。在27 269条全长转录本中预测到2 035条长链非编码RNA(lncRNA),并检测出14 892个简单重复序列(SSR)位点和1 856个转录因子。(2)基因注释结果表明,NR、GO、COG、KEGG 等8个数据库共注释了24 857条转录本,KEGG数据库共获得了124个条代谢途径,主要有核糖体、碳代谢、氨基酸生物合成等,在类黄酮和叶绿素代谢途径中分别有49和71个转录本参与。上述结果初步揭示了枫香叶片变色期转录组信息以及功能特性,为后续研究枫香叶片变色分子机制、色素代谢合成途径和调控、相关功能基因克隆以及叶色改良提供基础数据。     

An efficient CRISPR/Cas9-based genome editing system for alkaliphilic Bacillus sp. N16-5 and application in engineering xylose utilization for D-lactic acid production

Alkaliphiles are considered more suitable chassis than traditional neutrophiles due to their excellent resistance to microbial contamination. Alkaliphilic Bacillus sp. N16-5, an industrially interesting strain with great potential for the production of lactic acid and alkaline polysaccharide hydrolases, can only be engineered genetically by the laborious and time-consuming homologous recombination. In this study, we reported the successful development of a CRISPR/Cas9-based genome editing system with high efficiency for single-gene deletion, large gene fragment deletion and exogenous DNA chromosomal insertion. Moreover, based on a catalytically dead variant of Cas9 (dCas9), we also developed a CRISPRi system to efficiently regulate gene expression. Finally, this efficient genome editing system was successfully applied to engineer the xylose metabolic pathway for the efficient bioproduction of D -lactic acid. Compared with the wild-type Bacillus sp. N16-5, the final engineered strain with XylR deletion and AraE overexpression achieved 34.3% and 27.7% increases in xylose consumption and D -lactic acid production respectively. To our knowledge, this is the first report on the development and application of CRISPR/Cas9-based genome editing system in alkaliphilic Bacillus, and this study will significantly facilitate functional genomic studies and genome manipulation in alkaliphilic Bacillus, laying a foundation for the development of more robust microbial chassis.