Fishing for the Virome of Tropical Tuna

While planktonic viruses have received much attention in recent decades, knowledge of the virome of marine organisms, especially fish, still remains rudimentary. This is notably the case with tuna, which are among the most consumed fish worldwide and represent considerable economic, social and nutritional value. Yet the composition of the tuna virome and its biological and environmental determinants remain unknown. To begin to address this gap, we investigated the taxonomic diversity of viral communities inhabiting the skin mucus, gut and liver of two major tropical tuna species (skipjack and yellowfin) in individuals fished in the Atlantic and Indian Oceans. While we found significant differences in the virome composition between the organs, this was totally independent of the tuna species or sex. The tuna virome was mainly dominated by eukaryotic viruses in the digestive organs (gut and liver), while bacteriophages were predominant in the mucus. We observed the presence of specific viral families in each organ, some previously identified as fish or human pathogens (e.g., Iridoviridae, Parvoviridae, Alloherpesviridae, Papillomaviridae). Interestingly, we also detected a ‘core virome’ that was shared by all the organs and was mainly composed of Caudovirales, Microviridae and Circoviridae. These results show that tuna host a mosaic of viral niches, whose establishment, role and circulation remain to be elucidated.     

Identification,Genetic Characterization and Validation of Highly Diverse HIV-1 Viruses for Reference Panel Development

The continued diversification of HIV poses potentially significant challenges to HIV diagnostics and therapeutics. The dynamic evolution of emerging variants is highlighted in countries such as Cameroon in West Central Africa, where all known subtypes and circulating recombinant forms (CRFs) have been shown to be prevalent. We obtained several hundred HIV-positive plasma and viruses from this region for characterization and identification of highly divergent HIV strains. A total of 163 viral strains were cultured to high titers and high volumes using donor peripheral blood mononuclear cells (PBMCs). Initially, 101 viruses representing 59 strains were well characterized and categorized. Results showed that the viral load (VL) range was 0.36–398.9 × 10⁷ copies/mL, p24 values was 0.2–1134 ng/mL. Phylogenetic analysis of thirty-six near full-length HIV-1 genomic sequences demonstrated that most recombinants were highly diverse CRF02 containing unique recombinant forms (URFs). There were seven viral isolates identified as pure subtype/sub-subtypes (F2, A1, G, and D), six as CRFs (CRF06, CRF18, and CRF22), and ten as URFs. These extensively characterized reagents reflect the current dynamic and complex HIV epidemic in Cameroon and provide valuable insights into the potential phylogenetic evolutionary trend of global HIV molecular epidemiology in the future. These materials may be useful for development of HIV validation and reference panels to evaluate the performance of serologic antigen and nucleic acid assays for their ability to detect and quantitate highly divergent HIV strains.     

冬虫夏草促繁地土壤真菌种群结构的变性梯度凝胶电泳技术分析

目的 采用变性梯度凝胶电泳（DGGE）技术对冬虫夏草促繁地土壤真菌多样性进行初步研究。方法 利用PCR方法选择特异性引物ITS3-GC和ITS4扩增ITS rDNA基因的ITS2片段,结合DGGE分离技术,并借助生物信息学软件进行分析。结果 所测的土壤样品中真菌ITS2基因序列与GenBank已报道的丝盖伞属Inocybe (Fr.) Fr.、口蘑属Tricholoma (Fr.) Staude、根肿黑粉菌属Entorrhiza C.A. Weber及未确定的子囊菌Ascomycota、土壤真菌等的序列相似性较高,土壤真菌种群结构相似性仅有19.4%～50.1%。结论 冬虫夏草促繁地土壤真菌多样性丰富。     

Complexity of cancer stem cells

Heterogeneity of tumor tissue has been accounted for in recent years by a hierarchy‐based model in which cancer stem cells (CSCs) have the ability both to self‐renew and to give rise to differentiated tumor cells and are responsible for the overall organization of a tumor. Research into CSCs has progressed rapidly and concomitantly with recent advances in the biology of normal tissue stem cells, resulting in the identification of CSCs in a wide range of human tumors. Studies of mouse models of human cancer have provided further insight into the characteristics of CSCs as well as a basis for the development of novel therapies targeted to these cells. However, recent studies have revealed complexities, such as plasticity of stem cell properties and clonal diversity of CSCs, in certain tumor types that have led to revision of the original CSC model. In this review, we summarize the history of the discovery and characterization of CSCs, as well as address recent advances that have revealed the complexity of these cells and their therapeutic implications.     

云南金钗石斛居群DALP遗传变异研究

对云南7个金钗石斛居群和1个喇叭唇石斛居群,用5组DALP引物扩增得到140条清晰条带,其中102条为多态位点,多态比率72.86%,平均每组引物扩增所得多态条带为20.4。金钗石斛居群水平平均多态位点47.96%,多态位点在22.86%~68.57%;物种水平多态位点72.86%。DALP分析显示,金钗石斛物种水平的遗传多样性指数分别为PPB 72.86%,H 0.288 9,I 0.424 2;居群水平遗传多样性指数分别为PPB 47.96%,H 0.186 1,I 0.273 9。金钗石斛基因遗传分化系数G_st为0.338 6,即66.14%的遗传变异来自居群内,33.86%的遗传变异来自居群间,居群间存在较高水平的遗传分化。     

冬虫夏草可溶性蛋白质多样性与产地关联度初探

采用bradford法,以双向电泳技术对不同产地、不同初加工方式的冬虫夏草中可溶性蛋白质的含量、种类进行分析,发现冬虫夏草不同加工方法后可溶性蛋白差异明显.不同产地冬虫夏草中可溶性蛋白质多样性差异也较为明显.初步表明可溶性蛋白质含量、多样性指标与冬虫夏草加工方式、产地有一定的相关性.     

西藏麻花艽种质资源的遗传多样性分析

目的 对西藏不同产地17份麻花艽Gentiana straminea样品的遗传多样性进行比较分析。方法 居群采样,以相同产地同属近缘种粗茎秦艽G. crassicaulis为外类群比对,nrDNA ITS区序列分析,构建UPGMA系统树。结果 西藏产麻花艽nrDNA ITS区序列有1个多态性位点;外类群粗茎秦艽6份样品序列完全一致。结论 麻花艽与外类群种间区别明显;17份不同产地麻花艽被划分为2类,遗传多样性较为丰富,为西藏麻花艽药材品质评价及麻花艽核心种质的构建提供基础资料。     

Lack of genetic diversity in Crimean-Congo hemorrhagic fever viruses in Turkey: assessment of present and future patterns of disease

Crimean‐Congo hemorrhagic fever (CCHF) is a tick‐borne zoonosis which is common in Africa, Asia, Eastern Europe, and the Balkan Peninsula. CCHF has been reported in Turkey with high frequency since 2002. The aim of the present study was to investigate the genetic diversity and genetic relationship between CCHF virus (CCHFV) isolates derived from infected patients over a 2‐year period (2009 and 2010) in several provinces of Turkey. Serum samples (n = 48) were selected from CCHFV RNA positive patients and subjected to sequence analysis of the gene regions encoding the S (48 samples) and M (14 samples) segments. The nucleotide sequence alignments showed that the nucleic acid relatedness of CCHFV isolates ranged from 95.7% to 100% and from 93.7% to 100% for S and M segments, respectively. Phylogenetic analysis of both segment sequences revealed that CCHFV isolates circulating in Turkey belonged to the European lineage I and were closely related to the viruses found in the Eastern European‐Russian and Balkan Peninsula. The M gene segment‐based phylogenetic analysis suggested that 2/14 CCHFV isolates (KYSR3159/09 and YZGT714/10) had additional genetic variations. The results of the present study confirmed that the CCHFV isolates present in Turkey associated with human disease had high genetic homology in S segment, but some variability in the M segment of the RNA. J. Med. Virol. 84:471–478, 2012. © 2012 Wiley Periodicals, Inc.     

Genetic diversity of hantaviruses in Mexico: identification of three novel hantaviruses from Neotominae rodents

A variety of hantaviruses are harbored by rodents in North and South America, some of which can cause hantavirus pulmonary syndrome. To obtain greater evolutionary insight into hantaviruses in the Americas, a total of 211 rodents were captured in the Mexican states of Guerrero and Morelos in 2006. Anti-hantavirus antibodies were detected in 27 of 211 serum samples (12.8%) by ELISA. The distribution of seropositive rodents was: 17 Peromyscus beatae, 1 Megadontomys thomasi, 1 Neotoma picta, 6 Reithrodontomys sumichrasti, and 2 Reithrodontomys megalotis. The hantavirus small (S), medium (M), and large (L) genome segments from P. beatae, R. sumichrasti, and R. megalotis were amplified and the sequences covering the open reading frames were determined. The hantaviruses from P. beatae, R. sumichrasti, and R. megalotis were provisionally designated Montano (MTN), Carrizal (CAR), and Huitzilac (HUI), respectively. The M segment amino acid identities among the Mexican hantaviruses were 80.8-93.0%. When these M segments were compared to those of known hantaviruses, MTN virus was most closely related to Limestone Canyon (LSC) virus (88.9% amino acid identity), while the CAR and HUI viruses were most closely related to El Moro Canyon (ELMC) virus (90-91% identity). Phylogenetic analysis revealed that the MTN, CAR, and HUI viruses occupy a monophyletic clade with the LSC, ELMC, and Rio Segundo viruses, which are harbored by Peromyscus boylii, R. megalotis, and Reithrodontomys mexicanus, respectively. The data obtained in this study provide important information for understanding the evolution of hantaviruses in the Americas.