Análisis filogenético y de presión evolutiva de secuencias nucleotídicas del gen VP4 de especies de enterovirus humanos / Phylogenetic and evolutive pressure analyses of nucleotide sequences of VP4 gene of human enterovirus species

El género Enterovirus es un grupo viral que afecta a un amplio rango de hospederos, entre ellos los humanos (especies A, B, C, y D), causan enfermedades respiratorias, gastrointestinales, neurológicas, y otras, y son altamente contagiosos. Los síntomas pueden ser leves o graves. El objetivo del trabajo fue analizar la variación nucleotídica, filogenética y de presión evolutiva de secuencias nucleotídicas del gen VP4 de las cuatro especies que afectan a los humanos. Se emplearon 92 secuencias nucleotídicas disponibles en la base de datos GenBank; éstas se editaron con el software BioEdit y se alinearon con Clustal W; las relaciones filogenéticas se determinaron con MEGA6, y las presiones evolutivas con los algoritmos SNAP y SLAC. Se encontró que la identidad nucleotídica mínima intra-especie fue de 43,2% (especie B) a 72,6% (especie D). Los genotipos más variables por especie fueron EV-71 (A), Echovirus 2 (B), EV-118 (C), y EV-94 (D). El análisis de presión evolutiva mostró que el gen VP4 en las cuatro especies evoluciona bajo presión selectiva negativa. Esto indicaría que la alta tasa mutacional y eventos de recombinación no tienen un rol significativo en la evolución de este gen, debido probablemente a la localización interna de la proteína VP4.

The Enterovirus genus is a viral group that affects a wide host range, including humans (species A, B, C and D), cause respiratory, gastrointestinal, and neurologic disease, amongothers, and are highly contagious. The symptoms range from mild to severe. The objectiveof this study was to perform a nucleotidic variation, phylogenetic and selective pressureanalyses of the VP4 gene from the four enterovirus species that affect humans. Ninety-twonucleotide sequences (available in the GenBank database) were employed; they were edited with Bio Edit software and aligned with Clustal W; the phylogenetic relationships weredetermined with MEGA6, and the evolutive pressures with SNAP and SLAC algorithms. Itwas found an intra-species nucleotide identity of at least 43,2% (species B) to 72,6% (species D). The more variable genotypes by species were EV-71 (A), Echovirus 2 (B), EV-118 (C), and EV-94 (D). The selective pressure analysis showed that VP4 gene of the fourspecies evolves by negative pressure. This would indicate that the high mutation rate andrecombination events do not have a significant role in the evolution of this gene, probablydue to the internal localization of the VP4 protein.

Screening of the nucleotide sequences affected by α-synuclein in vitro / 中国药理学通报

Aim To study the screening of the nucleo-tide sequences might be affected by α-syn in vitro. Methods The nucleotide sequences were synthesized according to the feature of base composition, and then mixed with the α-syn-GFP. The CD was used to ana-lyse the changes of the peak. Result The peak of the CD changed greatly when the α-syn-GFP mixed with the GC-box like sequence. Conclusion The α-syn-GFP might affect the GC-box like sequence after trans-located into the nuclei. Then, it plays a role in physio-logical and pathological conditions by affecting the reg-ulation of gene expression.

Heterogeneous periodicity of drosophila mtDNA: new refutations of neutral and nearly neutral evolution

We found a consistent 3-site periodicity of the X²9 values for the heterogeneity of the distribution of the second base in relation to the first base of dinucleotides separated by 0 (contiguous), 1, 2, 3 ... 17 (K) nucleotide sites in Drosophila mtDNA. Triplets of X²9 values were found where the first was over 300 and the second and third ranged between 37 and 114 (previous studies). In this study, the periodicity was significant until separation of 2011K, and a structure of deviations from randomness among dinucleotides was found. The most deviant dinucleotides were G-G, G-C and C-G for the first, second and third element of the triplet, respectively. In these three cases there were more dinucleotides observed than expected. This inter-bases correlation and periodicity may be related to the tertiary structure of circular DNA, like that of prokaryotes and mitochondria, to protect and preserve it. The mtDNA with 19.517 bp was divided into four equal segments of 4.879 bp. The fourth sub-segment presented a very low proportion of G and C, the internucleotide interaction was weaker in this sub-segment and no periodicity was found. The maintenance of this mtDNA structure and organization for millions of generations, in spite of a high recurrent mutation rate, does not support the notion of neutralism or near neutralism. The high level of internucleotide interaction and periodicity indicate that every nucleotide is co-adapted with the residual genome.

Genetic variation of phosphoprotein (P) gene from measles epidemic strains in Zhejiang province / 中华流行病学杂志

Objective To investigate the genetic characteristics and variation within the phosphoprotein (P) gene of measles epidemic strains circulated in Zhejiang province. Methods The whole sequence of P gene of the epidemic strains related to Zhejiang Measles virus during 1999 to 2008 was amplified, using the RT-PCR Assay. PCR products were sequenced and compared with the sequences of measles vaccine and other epidemic strains. Results Totally, 1524 nucleotides were sequenced from each epidemic strain and 507 amino acids were derived correspondingly. Compared with the vaccine strain, there were 59-75 nucleotides (divergent ratios were 3.9%-4.9%) mutated from the epidemic strains, which were isolated during 1999 to 2008 and causing mutation on 36-42 amino acid (divergent ratios were 7.1%-8.3% ). Changes were also observed on the secondary structure. The phylogenetic tree, constructed based on the sequences of P gene, was similar to that based on the N gene, recommended by WHO. In addition, the average divergent ratio of P protein was greater than the ratio occurred on the N and H genes. Conclusion The variation within the P gene between the vaccine and epidemic strains circulated in Zhejiang province during 1999 to 2008 was significant.

Isolation and Complete Genomic Sequence Analysis of a New Sindbis-like Virus / 中国病毒学·英文版

The Sindbis-like virus was first discovered in China in 1986. Its complete genomic sequence consists of more than 11 000 bp encoding more than 3 700 amino acids. It contains a 5' non-transcriptional region (5'-NTR) in a non-structural region, four non-structural proteins (nsP1, nsP2, nsP3, nsP4) regions, capsids in conserved and non-conserved regions and structural E1, E2, E3, 6K regions and a 3' non-transcriptional region (3'-NTR). The Sindbis-IMB was isolated from the blood of a patient suspected to have encephalitis, and was followed by identification and passage. The virus RNA was extracted from virus supernatant in infected cells and the whole genome was divided into 12 fragments; RT-PCR was then performed to amplify the 12 fragments for complete sequencing. The results showed that the whole genomic sequence of Sindbis-IMB consists of 11 717 bp encoding 3 773 amino acids. Homology comparison with other Sindbis-like isolates demonstrated the highest similarity was the YN87448 with a variation of 1% strain isolated in Yunnan Province and the second highest to the SAAR86 strain with a variation of～1.2%.The nucleotide sequence variations were present in non-structural regions, resulting in amino acids K, E, N, R, H, and L in protein sequences in positions 230, 231, 443,781, 1 582, and 1746 in the new isolation respectively. Furthermore, three additional amino acids--glutamic acid, serine and alanine--were noted in nsp4 terminus as compared to the YN87448 isolate.

Detection and Genetic Characterization of Isolates of Hepatitis E Virus from Pigs and Human in Chungnam Region of Korea

Swine hepatitis E virus (HEV) has been reported as a new zoonotic agent due to its close genomic resemblance to the human HEV. Recently this virus is indicated as one of the important pathogens in xenotransplantation that uses pig as a donor animal. We carried out to investigate the prevalence of HEV infections among the pigs and human population in Chungnam region using a nested RT-PCR for detection of a part of HEV ORF2 gene. The sequences of the amplified DNA were analyzed and the genetical divergency were characterized. A total of 18 HEV strains, comprising 16 strains from pig and 2 strains from human, were genetically isolated from the fecal and serum samples. Among the isolates, 5 strains (2.5%) were detected from 200 swine sera and 2 strains (2.0%) from 100 human sera. All of the 16 swine strains were isolated from the pigs at 3 month of age, but none of age groups revealed the positive for swine HEV RNA. In comparison of the nucleotide sequence between 16 swine HEV and 2 human HEV isolates, the range of identities was 91.5% to 100%. Two human HEV isolates shared 99.7% homology. In phylogenetic analysis, all of the isolates were classified into genotype III, and the 18 isolates were also closely related to the prototype of swine HEV and human HEV strains isolated in the United States and others recently identified from swine in Japan and Netherland.

Detection and Genetic Characterization of Isolates of Hepatitis E Virus from Pigs and Human in Chungnam Region of Korea

Swine hepatitis E virus (HEV) has been reported as a new zoonotic agent due to its close genomic resemblance to the human HEV. Recently this virus is indicated as one of the important pathogens in xenotransplantation that uses pig as a donor animal. We carried out to investigate the prevalence of HEV infections among the pigs and human population in Chungnam region using a nested RT-PCR for detection of a part of HEV ORF2 gene. The sequences of the amplified DNA were analyzed and the genetical divergency were characterized. A total of 18 HEV strains, comprising 16 strains from pig and 2 strains from human, were genetically isolated from the fecal and serum samples. Among the isolates, 5 strains (2.5%) were detected from 200 swine sera and 2 strains (2.0%) from 100 human sera. All of the 16 swine strains were isolated from the pigs at 3 month of age, but none of age groups revealed the positive for swine HEV RNA. In comparison of the nucleotide sequence between 16 swine HEV and 2 human HEV isolates, the range of identities was 91.5% to 100%. Two human HEV isolates shared 99.7% homology. In phylogenetic analysis, all of the isolates were classified into genotype III, and the 18 isolates were also closely related to the prototype of swine HEV and human HEV strains isolated in the United States and others recently identified from swine in Japan and Netherland.

Embryogenesis in flowering plants: Recent approaches and prospects.

The overall architectural pattern of the mature plant is established during embryogenesis. Very little is known about the molecular processes that underlie embryo morphogenesis. Last decade has, nevertheless, seen a burst of information on the subject. The synchronous somatic embryogenesis system of carrot is largely being used as the experimental system. Information on the molecular regulation of embryogenesis obtained with carrot somatic embryos as well as observations on sandalwood embryogenic system developed in our laboratory are summarized in this review. The basic experimental strategy of molecular analysis mostly relied on a comparison between genes and proteins being expressed in embryogenic and non-embryogenic cells as well as in the different stages of embryogenesis. Events such as expression of totipotency of cells and establishment of polarity which are so critical for embryo development have been characterized using the strategy. Several genes have been identified and cloned from the carrot system. These include sequences that encode certain extracellular proteins (EPs) that influence cell proliferation and embryogenesis in specific ways and sequences of the abscisic acid (ABA) inducible late embryogenesis abundant (LEA) proteins which are most abundant and differentially expressed mRNAs in somatic embryos. That LEAs are expressed in the somatic embryos of a tree flora also is evidenced from studies on sandalwood. Several undescribed or novel sequences that are enhanced in embryos were identified. A sequence of this nature exists in sandalwood embryos was demonstrated using a Cuscuta haustorial (organspecific) cDNA probe. Somatic embryogenesis systems have been used to assess the expression of genes isolated from non-embryogenic tissues. Particular attention has been focused on both cell cycle and histone genes.

Genome analysis: A new approach for visualization of sequence organization in genomes.

In this article we describe and demonstrate the versatility of a computer program, GENOME MAPPING, that uses interactive graphics and runs on an IRIS workstation. The program helps to visualize as well as analyse global and local patterns of genomic DNA sequences. It was developed keeping in mind the requirements of the human genome sequencing programme, which requires rapid analysis of the data. Using GENOME MAPPING one can discern signature patterns of different kinds of sequences and analyse such patterns for repetitive as well as rare sequence strings. Further, one can visualize the extent of global homology between different genomic sequences. An application of our method to the published yeast mitochondrial genome data shows similar sequence organizations in the entire sequence and in smaller subsequences.

Antigenic relationship between reactivity to hepatitis B e antigen and 19 kDa protein of Mycobacterium tuberculosis among the Tibetan settlers in Karnataka.

McGlynn and her co-workers have reported that among the Vietnamese refugees in Philadelphia and among Alaskan natives who are hepatitis B carriers, there is a statistically significant association between a negative tuberculin test and the presence of hepatitis B e antigen. A repetition of this work among the population of Bangalore did not yield any significant results because of the very low incidence of hepatitis found among this population. However, on the basis of available data that hepatitis B infection is more prevalent among the Mongolian population than among people of other populations, the work was repeated among Tibetans who had settled down in Karnataka. This set of experiments showed that, contrary to the report of McGlynn et al, there is a statistically significant association between a positive tuberculin test and the presence of hepatitis B e antigen and that those individuals who showed the presence of hepatitis B e antigen exhibited less severe form of the disease than those who were negative to this antigen. These findings suggested that immunity to tuberculosis and hepatitis B infections may have a common underlying principle. Data bank search revealed a stretch of amino acid sequences which is common to hepatitis B e antigen and 19 kDa antigen of Mycobacterium tuberculosis. The significance of these results is discussed.