Chloroplast genomic characterization and phylogenetic analysis of Castanopsis hystrix / 生物工程学报

The structure and size of the chloroplast genome of Castanopsis hystrix was determined by Illumina HiSeq 2500 sequencing platform to understand the difference between C. hystrix and the chloroplast genome of the same genus, and the evolutionary position of C. hystrix in the genus, so as to facilitate species identification, genetic diversity analysis and resource conservation of the genus. Bioinformatics analysis was used to perform sequence assembly, annotation and characteristic analysis. R, Python, MISA, CodonW and MEGA 6 bioinformatics software were used to analyze the genome structure and number, codon bias, sequence repeats, simple sequence repeat (SSR) loci and phylogeny. The genome size of C. hystrix chloroplast was 153 754 bp, showing tetrad structure. A total of 130 genes were identified, including 85 coding genes, 37 tRNA genes and 8 rRNA genes. According to codon bias analysis, the average number of effective codons was 55.5, indicating that the codons were highly random and low in bias. Forty-five repeats and 111 SSR loci were detected by SSR and long repeat fragment analysis. Compared with the related species, chloroplast genome sequences were highly conserved, especially the protein coding sequences. Phylogenetic analysis showed that C. hystrix is closely related to the Hainanese cone. In summary, we obtained the basic information and phylogenetic position of the chloroplast genome of red cone, which will provide a preliminary basis for species identification, genetic diversity of natural populations and functional genomics research of C. hystrix.

Characteristics and phylogenetic analysis of chloroplast genome of a new type of fruit Rubus rosaefolius / 生物工程学报

The genomic DNA of Rubus rosaefolius was extracted and sequenced by Illumina NovaSeq platform to obtain the complete chloroplast genome sequence, and the sequence characteristics and phylogenetic analysis of chloroplast genes were carried out. The results showed that the complete chloroplast genome of the R. rosaefolius was 155 650 bp in length and had a typical tetrad structure, including two reverse repeats (25 748 bp each), a large copy region (85 443 bp) and a small copy region (18 711 bp). A total of 131 genes were identified in the whole genome of R. rosaefolius chloroplast, including 86 protein coding genes, 37 tRNA genes and 8 rRNA genes. The GC content of the whole genome was 36.9%. The genome of R. rosaefolius chloroplast contains 47 scattered repeats and 72 simple sequence repeating (SSR) loci. The codon preference is leucine codon, and the codon at the end of A/U is preferred. Phylogenetic analysis showed that R. rosaefolius had the closest relationship with R. taiwanicola, followed by R. rubraangustifolius and R. glandulosopunctatus. The chloroplast genome characteristics and phylogenetic analysis of R. rosaefolius provide a theoretical basis for its genetic diversity research and chloroplast development and utilization.

Chloroplast genomic characterization and phylogenetic analysis of Pellionia scabra / 生物工程学报

Pellionia scabra belongs to the genus Pellionia in the family of Urticaceae, and is a high-quality wild vegetables with high nutritional value. In this study, high-throughput techniques were used to sequence, assemble and annotate the chloroplast genome. We also analyzed its structure, and construct the phylogenetic trees from the P. scabra to further study the chloroplast genome characteristics. The results showed that the chloroplast genome size was 153 220 bp, and the GC content was 36.4%, which belonged to the typical tetrad structure in P. scabra. The chloroplast genome encodes 130 genes, including 85 protein-coding genes, 37 tRNA genes, and 8 rRNA genes in P. scabra. Among them, 15 genes contained 1 intron, 2 genes contained 2 introns, and rps12 had trans-splicing, respectively. In P. scabra, chloroplast genomes could be divided into four categories, including 43 photosynthesis, 64 self-replication, other 7 coding proteins, and 4 unknown functions. A total of 51 073 codons were detected in the chloroplast genome, among which the codon encoding leucine (Leu) accounted for the largest proportion, and the codon preferred to use A and U bases. There were 72 simple sequence repeats (SSRs) in the chloroplast genome of P. scabra, containing 58 single nucleotides, 12 dinucleotides, 1 trinucleotide, and 1 tetranucleotide. The ycf1 gene expansion was present at the IRb/SSC boundary. The phylogenetic trees showed that P. scabra (OL800583) was most closely related to Elatostema stewardii (MZ292972), Elatostema dissectum (MK227819) and Elatostema laevissimum var. laevissimum (MN189961). Taken together, our results provide worthwhile information for understanding the identification, genetic evolution, and genomics research of P. scabra species.

Bioprocess optimization of interferon ß-1-a in Pichia pastoris and its improved inhibitory effect against hepatocellular carcinoma cells

Interferon-ß-1a (INF-ß-1a) has gained significant attention due to its emerging applications in the treatment of different human diseases. Therefore, many researchers have attempted to produce it in large quantities and also in a biologically active form using different expression systems. In the present study, we aimed to improve the expression level of INF-ß-1a by Pichia pastoris using optimization of culture conditions. The codon-optimized INF-ß- 1a gene was cloned into pPICZαA plasmid under the control of alcohol oxidase I (AOX1) promoter. The protein expression was induced using different concentrations of methanol at different pHs and temperatures. The biological activity of produced protein was evaluated by anti-proliferative assay. The ideal culture conditions for the expression of INF-ß-1a by P. pastoris were found to be induction with 2% methanol at pH 7.0 culture medium at 30 C which yielded a concentration of 15.5 mg/L INF-ß-1a in a shake flask. Our results indicate that differences in glycosylation pattern could result in different biological activities as INF- ß-1a produced by P. pastoris could significantly more reduce the cell viability of HepG-2 cells, a hepatocellular carcinoma cell line, than a commercially available form of this protein produced by CHO

Effects of synonymous codon usage bias on mRNA half-life and translational regulation / 生物工程学报

With the widespread application of genomics and transcriptomics in the genetics and cell biology of different species, synonymous codon usage bias has been gradually accepted and used to study the deep connection between biological evolution and biological phenotypes. It is an important part of the life activities that mRNA is expressed into proteins with normal biological activities. The synonymous codon usage patterns, which were named as 'the second genetic codon', can express genetic information carried by themselves at the levels of transcriptional regulations, translational regulations and metabolic activities through molecular mechanisms such as fine-tune translation selection. Some studies have shown that the length of mRNA half-life has significant impacts on mRNA activity and the process of transcription and translation. This review summarized the roles of synonymous codon usage patterns in transcription, translational regulation and post-translational modification, with the aim to better understand how organisms skillfully utilize the genetic effects caused by codon usage patterns to accurately synthesize different types of proteins, so as to ensure the growth or differentiation of the specific gene expression procedures to carry out smoothly and maintain the normal life cycle.

High-level soluble expression of phospholipase D from Streptomyces chromofuscus in Escherichia coli by combinatorial optimization

BACKGROUND: Phospholipase D (PLD) is used as the biocatalyst for phosphatidylserine (PS) production. In general, PLD was expressed in insoluble form in Escherichia coli. High-level soluble expression of PLD with high activity in E. coli is very important for industrial production of PLD. RESULTS: Streptomyces chromofuscus PLD coding gene was codon-optimized, cloned without signal peptide, and expressed in E. coli. The optimal recombinant E. coli pET-28a+PLD/BL21(DE3) was constructed with pET-28a without His-tag. The highest PLD activity reached 104.28 ± 2.67 U/mL in a 250-mL shake flask after systematical optimization. The highest PLD activity elevated to 122.94 ± 1.49 U/mL by feeding lactose and inducing at 20 C after scaling up to a 5.0-L fermenter. Substituting the mixed carbon source with 1.0 % (w/v) of cheap dextrin and adding a feeding medium could still attain a PLD activity of 105. 81 ± 2.72 U/mL in a 5.0-L fermenter. Fish peptone from the waste of fish processing and dextrin from the starch are both very cheap, which were found to benefit the soluble PLD expression. CONCLUSIONS: After combinatorial optimization, the high-level soluble expression of PLD was fulfilled in E. coli. The high PLD activity along with cheap medium obtained at the fermenter level can completely meet the requirements of industrial production of PLD.

Optimization of expression conditions and determination the proteolytic activity of codon-optimized SARS-CoV-2 main protease in Escherichia coli / 生物工程学报

The main protease (Mpro) of SARS-CoV-2 is a highly conserved and mutation-resistant coronaviral enzyme, which plays a pivotal role in viral replication, making it an ideal target for the development of novel broad-spectrum anti-coronaviral drugs. In this study, a codon-optimized Mpro gene was cloned into pET-21a and pET-28a expression vectors. The recombinant plasmids were transformed into E. coli Rosetta(DE3) competent cells and the expression conditions were optimized. The highly expressed recombinant proteins, Mpro and Mpro-28, were purified by HisTrapTM chelating column and its proteolytic activity was determined by a fluorescence resonance energy transfer (FRET) assay. The FRET assay showed that Mpro exhibits a desirable proteolytic activity (25 000 U/mg), with Km and kcat values of 11.68 μmol/L and 0.037/s, respectively. The specific activity of Mpro is 25 times that of Mpro-28, a fusion protein carrying a polyhistidine tag at the N and C termini, indicating additional residues at the N terminus of Mpro, but not at the C terminus, are detrimental to its proteolytic activity. The preparation of active SARS-CoV-2 Mpro through codon-optimization strategy might facilitate the development of the rapid screening assays for the discovery of broad-spectrum anti-coronaviral drugs targeting Mpro.

Production of high-purity recombinant human vascular endothelial growth factor (rhVEGF165) by Pichia pastoris / 生物工程学报

Vascular endothelial growth factor (VEGF165) is a highly specific vascular endothelial growth factor that can be used to treat many cardiovascular diseases. The development of anti-tumor drugs and disease detection reagents requires highly pure VEGF165 (at least 95% purity). To date, the methods for heterologous expression and purification of VEGF165 require multiple purification steps, but the product purity remains to be low. In this study, we optimized the codons of the human VEGF165 gene (vegf165) according to the yeast codon preference. Based on the Pichia pastoris BBPB vector, we used the Biobrick method to construct a five-copy rhVEGF165 recombinant expression vector using Pgap as the promoter. In addition, a histidine tag was added to the vector. Facilitated by the His tag and the heparin-binding domain of VEGF165, we were able to obtain highly pure rhVEGF165 (purity > 98%) protein using two-step affinity chromatography. The purified rhVEGF165 was biologically active, and reached a concentration of 0.45 mg/mL. The new design of the expression vector enables production of active and highly pure rhVEGF165 ) in a simplified purification process, the purity of the biologically active natural VEGF165 reached the highest reported to date.

Avaliação das mutações nos códons 41 e 45 do gene codificante da betacatenina em pacientes portadores de tumor desmoide esporádico e sua associação com o prognóstico / Evaluation of mutations in codons 41 and 45 of the Beta-Catenin encoding gene in patients with sporadic desmoid tumors and its association with prognosis

O tumor desmoide (TD) é uma proliferação fibroblástica clonal rara, caracterizada por crescimento infiltrativo e tendência à recidiva local, embora incapaz de metastatizar. A maioria desses tumores é esporádica e contém mutações no gene que codifica a proteína betacatenina. Três mutações em dois códons do gene CTNNB1 foram identificadas como mais frequentes. O tratamento cirúrgico dessa doença tem se mostrado um verdadeiro desafio, e a identificação de fatores prognósticos poderia ajudar na caracterização de grupos com maior ou menor risco para desenvolver recidiva local após esse tratamento. O objetivo deste estudo foi avaliar mutações nos códons 41 e 45 do gene CTNNB1 em pacientes portadores de tumores desmoides esporádicos tratados com cirurgia, bem como avaliar a possível influência de variáveis clínicas, demográficas e moleculares na sobrevida livre de recidiva. Materiais e Métodos: Foi conduzido estudo retrospectivo, unicêntrico, transversal. Foram incluídos pacientes com diagnóstico de tumor desmoide submetidos à ressecção cirúrgica, que tinham dados clínicos e material biológico disponíveis. A correlação entre as variáveis qualitativas foi feita pelo teste qui-quadrado ou teste exato de Fisher; a comparação das variáveis quantitativas pelo teste U de Mann-Whitney ou pelo teste de Kruskal-Wallis; a análise de sobrevida livre de recidiva pela técnica de Kaplan-Meier; e os riscos relativos pela técnica de regressão de Cox uni ou multivariada. Resultados: No período de 1980 a 2015, foram identificados 107 pacientes. A maioria era do sexo feminino (58,9%), de etnia branca (78,9%), tinha idade entre 25 e 50 anos (58,9%), com lesões que se localizavam fora das extremidades (63,4%), apresentando tamanho menor que 10 centímetros (76,4%) e todos foram tratados cirurgicamente. O tempo de seguimento médio foi de 134 meses, a taxa global de sobrevida livre de recidiva (SLR) foi de 74,5% em 2 anos, 65,1% em 5 anos, 63,7% em 10 anos e 59,5% em 20 anos. Dos 107 pacientes que possuíam informações clínicas, foram obtidas 71 amostras tumorais para análise molecular que foi realizada utilizando NGS. Destes, 61 pacientes (85,9%) apresentavam alguma mutação nos códons 41 ou 45 do éxon 3 do gene CTNNB1 e 10 espécimes (14,1%) não tinham qualquer mutação nesses códons. Trinta e três (46,5%) pacientes apresentaram mutação T41A 16 (22,5%) S45F, 6 (8,5%) S45P, 5 (7%) T41A e S45F e 1 (1,4%) T41A e S45F, o valor médio da frequência alélica foi de 16,54%. Os pacientes com mutação S45F apresentaram taxa de sobrevida livre de recidiva em dois, cinco e dez anos menor do que os demais pacientes não mutados ou com outro tipo de mutação (26,7% 13,3% e 13,3% versus 78,4%, 68,1% e 65,4%, respectivamente). Na análise multivariada, tipo de mutação (RR = 5,25 IC [ 2,27­12,15]; p < 0,0001) e topografia (RR = 3,15 IC [1,35­ 7,33]; p = 0,008) foram fatores independentes para o risco de recidiva e o modelo prognóstico proposto evidenciou que os pacientes com alto risco (um ou dois fatores) podem apresentar até 8,36 vezes mais risco de recidiva local após o tratamento cirúrgico que os demais pacientes (IC [2,87­24,6]; p = 0,0001). Os resultados do presente estudo permitem concluir que o sequenciamento de segunda geração é um método adequado para detectar as mutações nos pacientes com tumores desmoides, e a mutação S45F esteve associada com maior risco de recidiva local. Em conjunto com outros fatores clínicos, a presença dessa mutação pode identificar um subgrupo de pacientes com elevado risco de recidiva. Esse achado pode auxiliar na indicação de cirurgias extensas e mutilantes, evitando a morbidade para um grupo específico de pacientes. Todavia, tais achados devem ser validados em uma coorte mais ampla de pacientes

The desmoid tumor (DT) is a rare (mono)clonal fibroblastic proliferation characterized by infiltrative growth with tendency to local recurrence although unable to metastasize. Most of these tumors are sporadic and contain mutations in the gene encoding Beta-Catenin. Three mutations in two codons of the CTNNB1 gene were identified as being more frequent. Surgical treatment of this disease has been revealed to be a real challenge and the identification of prognostic factors would help in the identification of groups with higher or lower risk to develop local recurrence after this treatment. The objective of this study was to evaluate mutations in codons 41 and 45 of the CTNNB1 gene in patients whose tumors were treated with surgery as well as to assess clinical and demographic variables and correlate them with relapse-free survival. Materials and Methods: a retrospective, unicentric, cross-sectional study was conducted. Patients diagnosed with desmoid tumor who were submitted to surgery, had clinical data and biological material available were included. The correlation between the qualitative variables was made by the chi-square test or Fisher exact test; the quantitative variables comparison by the Mann-Whitney U test or Kruskal-Wallis test; the relapse-free survival by Kaplan-Meier; and relative risks by the univariate or multivariate Cox regression technique. Results: 107 patients were identified from 1980 to 2015. The majority were female (58.9%), white (78.9%) 25-50 years old (58.9%), their lesions were located outside the extremities (63.4%), measured less than 10 centimeters (76.4%) and they were all surgically treated. Mean follow up period was 134 months, overall relapse-free survival rate (RFS) was 74.5% in 2 years, 65.1% in 5 years, 63.7% in 10 years and 59.5% in 20 years. From 107 patients who had clinical information, 71 samples were obtained for molecular analysis. Among these, 61 patients (85.9%) had mutations at codons 41 or 45 of exon 3 of the CTNNB1 gene and 10 specimens (14.1%) had no mutations at these codons. Thirty-three (46.5%) patients had mutation T41A 16 (22.5%) S45F, 6 (8,5%) S45P, 5 (7%) T41A and S45F and 1 (1,4%) T41A and S45F, the mean of allele frequency was 16.54%. Patients with mutation S45F had a relapse-free survival rate of two, five and 10 years smaller than the patients with no mutations or with a different mutation (26.7% 13.3% and 13.3% versus 78.4%, 68.1% and 65.4%, respectively). In the multivariate analysis, type of mutation (RR = 5,5 IC[2.27 ­ 12.15]; p < 0.0001) and topography (RR = 3.15 IC [1.35 ­ 7.33]; p = 0.008) correlated with risk of relapse and the proposed prognostic model demonstrated that high risk patients (one or two factors) may present a greater risk (up to 8.36 times) of local recurrence after surgical treatment than other patients (IC[2.87 ­ 24.6]; p = 0.0001). The results of the present study allow us to conclude that second generation sequencing is a suitable method to detect mutations in patients with desmoid tumors and the S45F mutation has been associated with an increased risk of local recurrence. Combined with other clinical factors, the presence of this mutation may identify a subgroup of patients with a high risk of relapse. This finding may support the indication of extensive and mutilating surgeries, avoiding morbidity for a specific group of patients. Nevertheless, such findings should be validated in a broader cohort of patients

Prediction of Chemotherapy-Induced Peripheral Neuropathy in Patients with Lymphoma and Myeloma: the Roles of Brain-Derived Neurotropic Factor Protein Levels and A Gene Polymorphism

BACKGROUND AND PURPOSE: Brain-derived neurotrophic factor (BDNF) is a neuronal growth factor that plays an essential role in the maintenance of the nervous system. We have evaluated the peripheral blood protein levels of BDNF and the valine-to-methionine substitution at codon 66 (Val66Met) single-nucleotide polymorphism (SNP) as potential biomarkers for the early recognition of chemotherapy-induced peripheral neuropathy (CIPN) in non-Hodgkin lymphoma and multiple myeloma patients. METHODS: CIPN was assessed in 45 patients at the diagnosis and during vincristine or bortezomib-based therapy using objective [reduced version of the Total Neuropathy Score (TNSr)] and subjective (FACT-GOG-NTx) tools. Depression was assessed using the Patient Health Questionnaire-9 (PHQ-9) questionnaire. BDNF protein levels and the Val66Met SNP were determined using ELISA and Sanger sequencing. RESULTS: The pretreatment BDNF protein level was inversely correlated with the maximum TNSr, FACT-GOG-NTx, and PHQ-9 scores in both genotypes. BDNF patients with the Val/Val genotype demonstrated significantly higher maximum FACT-GOG-NTx and PHQ-9 scores than those with the Val/Met and Met/Met genotypes (Met-BNDF carriers). Correlations between PHQ-9 and TNSr score were found only in Met-BDNF carriers, suggesting that peripheral neuropathy and depression coincide in Met-BDNF carriers. CONCLUSIONS: Determining the BDNF protein levels before initiating chemotherapy might be a useful tool for CIPN risk assessment and preemptive dose modification. The present data should be validated in larger studies that include other neurotoxic agents.

Comprehensive Cancer Panel Sequencing Defines Genetic Diversity and Changes in the Mutational Characteristics of Pancreatic Cancer Patients Receiving Neoadjuvant Treatment

BACKGROUND/AIMS: Pancreatic ductal adenocarcinoma (PDA) is associated with an extremely poor prognosis. This study assessed the genetic diversity among patients with PDA and compared their mutational profiles before and after treatment. METHODS: Tumors and matched blood samples were obtained from 22 PDA patients treated with neoadjuvant chemoradiation therapy. The somatic mutations were analyzed with comprehensive cancer gene panel (CCP). In addition, the biopsy samples obtained at diagnosis and the surgically resected samples after treatment were compared for seven patients. The CCP provided formalin-fixed paraffin-embedded sample-compatible multiplexed target selection for 409 genes implicated in cancer. RESULTS: Assessments of the MLH1, MLH3, MSH2, and PMS2 genes showed that the four patients with the highest relative burdens of mutations harbored somatic mutations in at least three of these genes. Genes in the histone-lysine N-methyltransferase 2 (KMT2) family, such as KMT2D, KMT2A, and KMT2C, were frequently mutated in tumor samples. Survival was worse in patients with ARID1A gene mutations than those without ARID1A gene mutations. Mutation patterns were compared between tissue samples before and after neoadjuvant treatment in seven patients who underwent surgical resection. The allelic fraction of mutations in KRAS codon 12 was lower in the surgically resected samples than in the endoscopic ultrasonography-guided fine needle aspiration biopsy samples of six patients. The number of mutant alleles of the histone lysine methyltransferase gene WHSC1 also decreased after treatment. CONCLUSIONS: These results indicate that tumor tissue from PDA patients is genetically diverse and suggest that ARID1A mutations may be a potential prognostic marker for PDA.

Familial Creutzfeldt–Jakob Disease with a PRNP Mutation at Codon 180 Presented with Visual Hallucinations and Illusions

No abstract available.

Expression of Pichia pastoris tRNAProCCG and its function / 生物工程学报

Translocation ribonucleic acid (tRNA) is one of the important components in protein synthesis. In order to explore the effect of the changes of tRNAs corresponding to rare codons (rarity tRNAs) on the expression of exogenous genes, the co-expression system of rare tRNA gene and exogenous gene in Pichia pastoris was constructed. The expression of GFP in P. pastoris can be greatly reduced when a repressor region composed of four continuous proline rare codon CCG was added into the GFP gene. The expression amount of the repressed GFP could be increased about 4.9% when tRNAProCCG gene was cointegrated to the 3' of the repressed GFP gene through pPIC9K to the genome of P. pastoris GS115. Meanwhile, the expression amount of the repressed GFP increased about 12.5% by integrating the repressed GFP gene and tRNAProCCG gene to the genome of P. pastoris GS115 through pPIC9K and pFLDα, respectively. Using the same method, NFATc3T-GFP fusion gene and tRNAProCCG gene were co-expressed in P. pastoris GS115 resulting in 21.3% increased of the expression amount of NFATc3T-GFP fusion protein. In conclusion, tRNAProCCG gene has been confirmed to be a kind of rare tRNAs in P. pastoris GS115. Through co-expression of tRNAProCCG gene and heterologous genes which containing the continuous rare codon CCG, the expression of the repressed heterologous genes could be increased significantly. Furthermore, this co-expression system would contribute to screening and determining the other rare tRNAs.

Application of codon optimization strategy in heterologous protein expression / 生物工程学报

Enzymes are widely used in medical and biopharmaceuticals. They can be used not only for various disease treatments, but also clinical diagnosis. The use of microorganisms to express heterologous proteins has become the easiest and fastest way to obtain enzymes. In order to obtain high concentration and high-quality heterologous proteins, a common method is codon optimization of gene sequences. The traditional codon optimization strategy is mainly based on codon bias and GC content, ignoring complex and varied factors such as translational dynamics and metabolic levels. We provide here comprehensive codon optimization strategy based on gene level, transcriptional level, translational level, post-translational level and metabolic level, mainly including codon bias, codon harmonization, codon sensitivity, adjustment of gene sequence structure and some other influencing factors. We also summarize the aspects of strategy content, theoretical support and application. Besides, the advantages and disadvantages of each strategy are also systematically compared, providing an all-round, multi-level and multi-selection optimization strategy for heterogeneous protein expression, and also providing references for the enzyme industry and biopharmaceuticals.

NS1 codon usage adaptation to humans in pandemic Zika virus

BACKGROUND Zika virus (ZIKV) was recognised as a zoonotic pathogen in Africa and southeastern Asia. Human infections were infrequently reported until 2007, when the first known epidemic occurred in Micronesia. After 2013, the Asian lineage of ZIKV spread along the Pacific Islands and Americas, causing severe outbreaks with millions of human infections. The recent human infections of ZIKV were also associated with severe complications, such as an increase in cases of Guillain-Barre syndrome and the emergence of congenital Zika syndrome. OBJECTIVES To better understand the recent and rapid expansion of ZIKV, as well as the presentation of novel complications, we compared the genetic differences between the African sylvatic lineage and the Asian epidemic lineage that caused the recent massive outbreaks. FINDINGS The epidemic lineages have significant codon adaptation in NS1 gene to translate these proteins in human and Aedes aegypti mosquito cells compared to the African zoonotic lineage. Accordingly, a Brazilian epidemic isolate (ZBR) produced more NS1 protein than the MR766 African lineage (ZAF) did, as indicated by proteomic data from infections of neuron progenitor cells-derived neurospheres. Although ZBR replicated more efficiently in these cells, the differences observed in the stoichiometry of ZIKV proteins were not exclusively explained by the differences in viral replication between the lineages. MAIN CONCLUSIONS Our findings suggest that natural, silent translational selection in the second half of 20th century could have improved the fitness of Asian ZIKV lineage in human and mosquito cells.

Genomic Insights into the Rice Blast Fungus through Estimation of Gene Emergence Time in Phylogenetic Context

The rice blast fungus, Magnaporthe oryzae, is an important pathogen of rice plants. It is well known that genes encoded in the genome have different evolutionary histories that are related to their functions. Phylostratigraphy is a method that correlates the evolutionary origin of genes with evolutionary transitions. Here we applied phylostratigraphy to partition total gene content of M. oryzae into distinct classes (phylostrata), which we designated PS1 to PS7, based on estimation of their emergence time. Genes in individual phylostrata did not show significant biases in their global distribution among seven chromosomes, but at the local level, clustering of genes belonging to the same phylostratum was observed. Our phylostrata-wide analysis of genes revealed that genes in the same phylostratum tend to be similar in many physical and functional characteristics such as gene length and structure, GC contents, codon adaptation index, and level of transcription, which correlates with biological functions in evolutionary context. We also found that a significant proportion of genes in the genome are orphans, for which no orthologs can be detected in the database. Among them, we narrowed down to seven orphan genes having transcriptional and translational evidences, and showed that one of them is implicated in asexual reproduction and virulence, suggesting ongoing evolution in this fungus through lineage-specific genes. Our results provide genomic basis for linking functions of pathogenicity factors and gene emergence time.

Identification of missing proteins in Saccharomyces cerevisiae by small protein-based enrichment / 生物工程学报

Small proteins (SPs) are defined as peptides of 100 amino acids or less encoded by short open reading frames (sORFs). SPs participate in a wide range of functions in cells, including gene regulating, cell signaling and metabolism. However, most annotated SPs in all living organisms are currently lacking expression evidence at the protein level and regarded as missing proteins (MPs). High efficient SPs identification is the prerequisite for their functional study and contribution to MPs searching. In this study, we identified 72 SPs and successfully validated 9 MPs from Saccharomyces cerevisiae based on SPs enrichment strategy. In-depth analysis showed that the missing factors of MPs were low molecular weight, low abundant, hydrophobicity, lower codon usage bias and unstable. The small protein-based enrichment can be used as MPs searching strategy, which might provide the foundation for their further function research.

Whole exome sequencing identifies an AMBN missense mutation causing severe autosomal-dominant amelogenesis imperfecta and dentin disorders / 国际口腔科学杂志·英文版

Tooth development is a complex process that involves precise and time-dependent orchestration of multiple genetic, molecular, and cellular interactions. Ameloblastin (AMBN, also named "amelin" or "sheathlin") is the second most abundant enamel matrix protein known to have a key role in amelogenesis. Amelogenesis imperfecta (AI [MIM: 104500]) refers to a genetically and phenotypically heterogeneous group of conditions characterized by inherited developmental enamel defects. The hereditary dentin disorders comprise a variety of autosomal-dominant genetic symptoms characterized by abnormal dentin structure affecting either the primary or both the primary and secondary teeth. The vital role of Ambn in amelogenesis has been confirmed experimentally using mouse models. Only two cases have been reported of mutations of AMBN associated with non-syndromic human AI. However, no AMBN missense mutations have been reported to be associated with both human AI and dentin disorders. We recruited one kindred with autosomal-dominant amelogenesis imperfecta (ADAI) and dentinogenesis imperfecta/dysplasia characterized by generalized severe enamel and dentin defects. Whole exome sequencing of the proband identified a novel heterozygous C-T point mutation at nucleotide position 1069 of the AMBN gene, causing a Pro to Ser mutation at the conserved amino acid position 357 of the protein. Exfoliated third molar teeth from the affected family members were found to have enamel and dentin of lower mineral density than control teeth, with thinner and easily fractured enamel, short and thick roots, and pulp obliteration. This study demonstrates, for the first time, that an AMBN missense mutation causes non-syndromic human AI and dentin disorders.

Mitochondrial 10398A>G NADH-Dehydrogenase Subunit 3 of Complex I Is Frequently Altered in Intra-Axial Brain Tumors in Malaysia

BACKGROUND: Mitochondria are major cellular sources of reactive oxygen species (ROS) generation which can induce mitochondrial DNA damage and lead to carcinogenesis. The mitochondrial 10398A>G alteration in NADH-dehydrogenase subunit 3 (ND3) can severely impair complex I, a key component of ROS production in the mitochondrial electron transport chain. Alteration in ND3 10398A>G has been reported to be linked with diverse neurodegenerative disorders and cancers. The aim of this study was to find out the association of mitochondrial ND3 10398A>G alteration in brain tumor of Malaysian patients. METHODS: Brain tumor tissues and corresponding blood specimens were obtained from 45 patients. The ND3 10398A>G alteration at target codon 114 was detected using the PCR-RFLP analysis and later was confirmed by DNA sequencing. RESULTS: Twenty-six (57.8%) patients showed ND3 10398A>G mutation in their tumor specimens, in which 26.9% of these mutations were heterozygous mutations. ND3 10398A>G mutation was not significantly correlated with age, gender, and histological tumor grade, however was found more frequently in intra-axial than in extra-axial tumors (62.5% vs. 46.2%, p G mutations in a Malaysian brain tumor population. It can be concluded that mitochondrial ND3 10398A>G alteration is frequently present in brain tumors among Malaysian population and it shows an impact on the intra-axial tumors.

Patterns of rpoC Mutations in Drug-Resistant Mycobacterium tuberculosis Isolated from Patients in South Korea / 결핵및호흡기질환

BACKGROUND: Rifampicin (RFP) is one of the principal first-line drugs used in combination chemotherapies against Mycobacterium tuberculosis, and its use has greatly shortened the duration of chemotherapy for the successful treatment of drug-susceptible tuberculosis. Compensatory mutations have been identified in rpoC that restore the fitness of RFP-resistant M. tuberculosis strains with mutations in rpoB. To investigate rpoC mutation patterns, we analyzed 93 clinical M. tuberculosis isolates from patients in South Korea. METHODS: Drug-resistant mycobacterial isolates were cultured to determine their susceptibility to anti-tubercular agents. Mutations in rpoC were identified by sequencing and compared with the relevant wild-type DNA sequence. RESULTS: In total, 93 M. tuberculosis clinical isolates were successfully cultured and tested for drug susceptibilities. They included 75 drug-resistant tuberculosis species, of which 66 were RFP-resistant strains. rpoC mutations were found in 24 of the 66 RFP-resistant isolates (36.4%). Fifteen different types of mutations, including single mutations (22/24, 91.7%) and multiple mutations (2/24, 8.3%), were identified, and 12 of these mutations are reported for the first time in this study. The most frequent mutation involved a substitution at codon 452 (nt 1356) resulting in amino acid change F452L. CONCLUSION: Fifteen different types of mutations were identified and were predominantly single-nucleotide substitutions (91.7%). Mutations were found only in dual isoniazid- and RFP-resistant isolates of M. tuberculosis. No mutations were identified in any of the drug-susceptible strains.