Complete genome comparative analysis of Coxsackievirus A6 causing hand,foot and mouth disease and herpangina in Yunnan Province in 2018 / 中国生物制品学杂志

@#ObjectiveTo analyze the genome-wide characteristics of 17 strains of Coxsackievirus A6(CVA6)that cause hand,foot and mouth disease(HFMD)and herpangina(HA)in Yunnan Province in 2018,and understand the genetic differences between different pathogenic CVA6.MethodsA total of 1 909 stool samples clinically diagnosed as HFMD and HA in Kunming Children′s Hospital in 2018 were randomly selected for detection using enterovirus group A universal primers and screening of CVA6 positive samples. The CVA6 whole genome sequence was amplified with CVA6 whole genome primers,spliced by BioEdit splicting software,and analyzed for the whole genome characteristics by BioEdit,MEGA 7.0,Simplot,Heml 1.0 and Phyre2softwares.ResultsA total of 929 CVA6 positive samples were screened,and 17CVA6 complete gene sequences were obtained(9 of which were clinically diagnosed as HFMD and 8 were clinically diagnosed as HA). All 17 CVA6 strains were in type IV clade on the whole phylogenetic tree. No significant recombination occurred in HA and HFMD representative strains,while mutations occurred in non-structural protein 3D region. HFMD and HA representative strains showed differences in VP1 loci S597T,Q705L and Q663L. Online predictive analysis showed that the secondary structure of VP1 was consistent with that of CVA6 with no change.ConclusionThe 17 CVA6 strains causing HFMD and HA had high genomic homology,as well as nucleotide and amino acid differences,which may affect the replication and adaptability of CVA6.

Evolutionary analysis of the VP1 gene of Echovirus 30 in Yunnan Province, China / 国际生物医学工程杂志

Objective:To study the genetic characteristics and genetic evolution of echovirus 30 (ECHO30) isolates in Yunnan Province, China.Methods:Virus isolation was performed on nucleic acid-positive samples for hand, foot, and mouth disease pathogen surveillance in Yunnan Province, and VP1 gene sequencing was performed. The sequences of eight ECHO30 isolates from Yunnan Province and the gene sequences of the VP1 region of the ECHO30 reference strain downloaded from GenBank were compared and analyzed using MEGA 5.0 software, and then a phylogenetic tree was constructed to measure the homology of nucleotides and amino acids between the isolates.Results:The ECHO30 virus was distributed in Wenshan, Qujing, Chuxiong, and Kunming in Yunnan Province. The ECHO30 virus was relatively common in Wenshan. ECHO30 isolates belonged to the H2 subtype of the H genotype, which was close to the local reference strain LC120939 in Yunnan Province. On the VP1 gene at site 5, the amino acid change ratio was more active, the amino acids were diverse, and mutations also occurred at sites 54, 156, 258, and so on. Nucleotide and amino acid homology were 84.0% - 100.0% and 98.4% - 100.0%, respectively.Conclusions:ECHO30 isolates from Yunnan Province have certain geographical characteristics and belong to H2 of the H genotype. The nucleotide differences in virus sequences among subtypes are small and have a close genetic relationship.

HCV evolution and positive selection sites of HCV NS5B region among intravenous drug users in Guangdong / 中国输血杂志

【Objective】 To learn the situation of the evolution process of HCV virus population and the selection pressure of HCV NS5B in intravenous drug users (IDUs) in Guangdong. 【Methods】 141 blood samples from hepatitis C virus (HCV) RNA-positive blood donors and 58 from HCV patients in Guangdong were randomly collected for HCV NS5B sequence amplification, combined with HCV NS5B sequences from blood donors and IDUs obtained by sequencing previously(between 2009 and 2011). Homology analysis was performed by Molecular Evolutionary Genetics Analysis (MEGA) software, evolutionary analysis were performed by Bayesian Evolutionary Analysis Sampling Trees (BEAST) software package. Selection pressure analysis was performed on sequences isolated from IDUs by Datamonkey online software package with Mixed Effects Model Evolution (MEME) method, and the population expansion of species were analyzed using Tajima and Fu neutrality test by Arlequin software. 【Results】 The comparison results of internal homology among different subtypes of IDUs in this group were as follows : HCV-3b had the highest homology (97%), followed by HCV-3a (96%), HCV-6a (95%) and HCV-1b (94%); HCV evolution rate analysis showed that HCV-1b had the fastest evolution rate [2.17E-03 substitutions/site/year (y/y/y)], followed by HCV-3b (2.12E-0 y/y/y), HCV-3a (1.58E-03 y/y/y) and HCV-6a (1.28E-03 y/y/y). The analysis on effective population of HCV: 1980~1990 was rapid growth period for HCV-6a, 1990~1995 period for HCV-1b, and 2000~2007 period for HCV-3a. HCV population genetic characteristics was as follows: HCV-1b, 3a, 3b and 6a experienced population expansion, among which 3a and 3b were the most obvious. As to the analysis of HCV selection pressure, two positive selection sites (235 and 243)were found in the 339 nucleotide fragment of the NS5B sequence in injecting drug users, but mutation only occurred at position 316 [mutation rate 1.24% (14/1 130)] among 5 direct antiviral drug (DAA) sites in this gene. 【Conclusion】 The evolution of HCV-3b in Guangdong has showed an obvious trend of population expansion, with a high proportion and homology especially in the local IDUs. HCV-3b should be the focus of HCV prevention and control in this region. Given that the positively selected sites of the HCV NS5B gene region of IDUs in Guangdong are non-DAA binding sites, DAA is expected to demonstrate a good effect on these patients.

Identification and analysis of the TALE transcription factor family in radish / 生物工程学报

Three-amino acid loop extension (TALE) transcription factors play important roles in plant growth and cell differentiation. There are plenty of studies on TALE transcription factors in several model plants, but not in radish (Raphanus sativas). A genome-wide bioinformatics analysis identified 33 TALE family genes in the Xiang-Ya-Bai (XYB) radish, These genes, are distributed on nine chromosomes and all contain 4-6 exons. The 33 TALE genes in radish showed a co-linearity relationship with the 17 homologous genes in Arabidopsis thaliana. Moreover, a large number of stress response cis-elements were found in the promoter regions of these genes. Expression analysis showed that four genes in the BELL subfamily were highly expressed in roots, and two genes in the KNOX subfamily were highly expressed in shoots of bolting plants and callus. All radish TALE genes contain sequences encoding the conserved HOX domain, except for the gene RSA10037940, which is homologous to Arabidopsis KNATM. The deduced 3D structures of the TALE proteins irrespective of subtypes are highly similar. All the encoded proteins were weakly acidic and hydrophilic. The radish TALE gene family is relatively evolutionarily conserved, which was consistent with results from Arabidopsis, but quite different from that of rice. This study provides important clues for studying the biological functions of TALE transcription factors in radish.

Analysis on YABBY Transcription Factor Family of Original Plant Cannabis sativa of Traditional Chinese Medicine Cannabis Fructus / 中国实验方剂学杂志

Objective:To analyze the sequence characteristics，chromosomal location，gene structure，conserved motifs，phylogenetic evolution and differential gene expressions of the <italic>Cannabis sativa</italic> YABBY transcription factor family，in order to provide a molecular basis for in-depth study of <italic>YABBY</italic> gene function and theoretical support for the selection and breeding of superior hemp varieties. Method:The bio-informatics method was used to identify and analyze the <italic>CsYABBY </italic>gene family of the original hemp seed plant. PlantTFDB，ExPASy，MEME，CELLO，PLANTCARE and other online websites and TBtools，MEGA，DNAMAN and other software were used for prediction，visualization and analysis. Result:<italic>C. sativa</italic> contains 6 <italic>YABBY</italic> gene members distributed on 5 chromosomes，in which 5 members are localized in the nucleus and 1 in extracellular， they consist of 185-235 amino acids， and the isoelectric point is between 5.05 and 9.34， the molecular weight is between 20 582.45-26 282.7 Da. All of CsYABBY proteins contain two conserved domains， namely Zinc finger domain and YABBY domain. <italic>CsYABBY</italic> genes have multiple cis-acting elements，and their expressions differ in different tissues and cultivars. Conclusion:The expressions of CsYABBY may be affected by hormones and externally environmental factors. <italic>CsYABBY</italic> gene expressions are tissue-specific. In addition，YABBY transcription factor family may play an important role in regulating the development of <italic>C. sativa</italic> female flowers，and subfamilies YAB1 and YAB5 may be involved in the synthesis of cannabinoids.

Bioinformatics analysis and function prediction of ginseng TCP transcription factor family / 中国中药杂志

The longevity mechanism of ginseng(Panax ginseng) is related to its strong meristematic ability. In this paper, this study used bioinformatic methods to identify the members of the ginseng TCP gene family in the whole genome and analyzed their sequence characteristics. Then, quantitative real-time fluorescent PCR was performed to analyze the TCP genes containing elements rela-ted to meristem expression in the taproots, fibrous roots, stems, and leaves. According to the data, this study further explored the expression specificity of TCP genes in ginseng tissues, which facilitated the dissection of the longevity mechanism of ginseng. The ginseng TCP members were identified and analyzed using PlantTFDB, ExPASy, MEME, PLANTCARE, TBtools, MEGA and DNAMAN. The results demonstrated that there were 60 TCP gene family members in ginseng, and they could be divided into two classes: Class Ⅰ and Class Ⅱ, in which the Class Ⅱ possessed two subclasses: CYC-TCP and CIN-TCP. The deduced TCP proteins in ginseng had the length of 128-793 aa, the isoelectric point of 4.49-9.84 and the relative molecular mass of 14.2-89.3 kDa. They all contained the basic helix-loop-helix(bHLH) domain. There are a variety of stress response-related cis-acting elements in the promoter regions of ginseng TCP genes, and PgTCP20-PgTCP24 contained the elements associated with meristematic expression. The transcription levels of PgTCP20-PgTCP24 were high in fibrous roots and leaves, but low in stems, indicating the tissue-specific expression of ginseng TCP genes. The Class Ⅰ TCP members which contained PgTCP20-PgTCP23, may be important regulators for the growth and development of ginseng roots.

Application of CRISPR in evolution analysis, detecting and typing, virulence and antibiotic resistance regulation in food-borne pathogens / 生物工程学报

Clustered regularly interspaced short palindromic repeats (CRISPR) and its associated protein gene system can limit the horizontal gene transfer, thereby effectively preventing the invasion of foreign gene elements such as bacteriophages. CRISPR arrays of different bacteria are diverse. Based on the differences in the CRISPR system, this review summarizes the application of CRISPR in food-borne pathogen evolution analysis, detection and typing, virulence and antibiotic resistance in recent years. We also address bacterial detection typing method developed based on the characteristics of CRISPR arrays and the association of CRISPR with virulence and drug resistance of food-borne pathogens. The shortcomings of CRISPR in evolution, detection and typing, virulence and resistance applications are analyzed. In addition, we suggest standardizing CRISPR typing methods, improving and expanding the CRISPR database of pathogenic bacteria, and further exploring the co-evolution relationship between phages and bacteria, to provide references for further exploration of CRISPR functions.

Molecular and serological detection of Leishmania spp. in horses from an endemic area for canine visceral leishmaniasis in southeastern Brazil / Detecção molecular e sorológica de infecção por Leishmania (Leishmania) infantum em cavalos na região Sudeste do Brasil

This study aimed to verify the occurrence of Leishmania spp. and Leishmania (Leishmania) infantum in horses from a visceral leishmaniasis endemic area in Brazil. DNA samples from blood and conjunctival swab (CS) were tested by PCR and Indirect Immunofluorescence Antibody Test (IFAT). Although none of the horses was clinically sick, animals infected by Leishmania spp. were found and some could be characterized as infected by L. (L.) infantum. From 40 horses, 100% of the animals were positive by blood PCR, 90% (36/40) by CS PCR, and 2.5% (01/40) in serodiagnosis, by IFAT. Six from these 40 horses were L. (L.) infantum positive by blood PCR. Direct sequencing and analysis of amplicons resulted in a sequence to evolutionary analysis. Results indicate the presence of Leishmania spp. and L. (L.) infantum infecting healthy horses in Brazil. The presence of Leishmania spp. and L. (L.) infantum DNA in asymptomatic horses suggests that they can be important reservoirs of these parasites, a highly relevant finding for the epidemiological surveillance of the diseases they cause.(AU)

O estudo objetivou verificar a ocorrência de Leishmania spp. e Leishmania (Leishmania) infantum em cavalos de uma região endêmica para leishmaniose visceral do Brasil. Amostras de DNA de sangue e suabe conjuntival (SC) foram testadas pela PCR e pela Reação de Imunofluorescência Indireta (RIFI). Embora nenhum cavalo estivesse clinicamente doente, animais infectados por Leishmania spp. e L. (L.) infantum foram encontrados em Ilha Solteira/SP. Dos 40 cavalos, 100% (40/40) foram positivos pela PCR de sangue, 90% (36/40) pela PCR de SC, e 2,5% (01/40) no sorodiagnóstico, pela RIFI. Seis desses 40 cavalos foram positivos para L. (L.) infantum pela PCR de sangue. O sequenciamento direto e a análise dos amplicons resultaram em uma sequência para análise evolutiva. Os resultados indicam a presença de Leishmania spp. e L. (L.) infantum infectando cavalos saudáveis no Brasil. A presença de DNA de Leishmania spp. and L. (L.) infantum em cavalos saudáveis sugere que eles podem ser importantes reservatórios desses parasitas, um achado altamente relevante para a vigilância epidemiológica das doenças que causam.(AU)

Evolution of equine influenza viruses (H3N8) during a Brazilian outbreak, 2015

Abstract Equine influenza is one of the major respiratory infectious diseases in horses. An equine influenza virus outbreak was identified in vaccinated and unvaccinated horses in a veterinary school hospital in São Paulo, SP, Brazil, in September 2015. The twelve equine influenza viruses isolated belonged to Florida Clade 1. The hemagglutinin and neuraminidase amino acid sequences were compared with the recent isolates from North and South America and the World Organisation for Animal Health recommended Florida Clade 1 vaccine strain. The hemagglutinin amino acid sequences had nine substitutions, compared with the vaccine strain. Two of them were in antigenic site A (A138S and G142R), one in antigenic site E (R62K) and another not in antigenic site (K304E). The four substitutions changed the hydrophobicity of hemagglutinin. Three distinct genetic variants were identified during the outbreak. Eleven variants were found in four quasispecies, which suggests the equine influenza virus evolved during the outbreak. The use of an out of date vaccine strain or updated vaccines without the production of protective antibody titers might be the major contributing factors on virus dissemination during this outbreak.

Continued circulation and phylogenetic analysis of human adenovirus-55 in China during 2006-2016 / 中华实验和临床病毒学杂志

Objective@#To better understand the evolution and epidemiology of human adenovirus-55 (HAdV-55) and provide a scientific basis for the prevention and control of the epidemic of HAdV-55 in China.@*Methods@#HAdV-55 isolates from 5 provinces in China included Beijing, Hebei, Shandong, Hunan and Yunnan were collected during 2011-2014. The hexon, fiber and penton base gene were sequenced, and compared with other strains of HAdV-55 sequences downloaded from GenBank for homology and evolution analysis.@*Results@#During the past decade, HAdV-55 was found in 15 provinces throughout China. Genetic and phylogenetic analysis showed that the HAdV-55 virus is highly conservative in evolution due to aggregation in a branch in the evolutionary tree. However, bayesian phylogenetic tree shows a certain time evolution trend. The evolution rate of hexon and fiber gene of HAdV-55 are 5.228×10-5 and 1.238×10-4 substitutions/site/year respectively, and the latest coevolutionary ancestor tMRCA of hexon gene can be traced back to 1963.@*Conclusions@#HAdV-55 has been widely spread and continued circulating in China. Establishing effective monitoring system and conducting vaccine related research is very important for its control and prevention.

Mayaro virus infection, the next epidemic wave after Zika? Evolutionary and structural analysis

Objective:To evaluate the evolution of the pathogen Mayaro virus, causing Mayaro fever (a mosquito-borne disease) and to perform selective pressure analysis and homology modelling.Methods:Nine different datasets were built, one for each protein (from protein C to non-structural protein 4) and the last one for the complete genome. Selective pressure and homology modelling analyses were applied.Results:Two main clades (A and B) were pointed in the maximum likelihood tree. The clade A included five Brazilian sequences sampled from 1955 to 2015. The Brazilian sequence sampled in 2014 significantly clustered with the Haitian sequence sampled in 2015. The clade B included the remaining 27 sequences sampled in the Central and Southern America from 1957 to 2013. Selective pressure analysis revealed several sites under episodic diversifying selection in envelope surface glycoprotein E1, non-structural protein 1 and non- structural protein 3 with a posterior probability P≤0.01. Homology modelling showed different sites modified by selective pressure and some protein-protein interaction sites at high interaction propensity.Conclusion:Maximum likelihood analysis confirmed the Mayaro virus previous circulation in Haiti and the successful spread to the Caribbean and USA. Selective pressure analysis revealed a strong presence of negatively selected sites, suggesting a probable purging of deleterious polymorphisms in functional genes. Homology model showed the position 31, under selective pressure, located in the edge of the ADP-ribose binding site predicting to possess a high potential of protein-protein interaction and suggesting the possible chance for a protective vaccine, thus preventing Mayaro virus urbanization as with Chikungunya virus.

Mayaro virus infection, the next epidemic wave after Zika? Evolutionary and structural analysis

Objective: To evaluate the evolution of the pathogen Mayaro virus, causing Mayaro fever (a mosquito-borne disease) and to perform selective pressure analysis and homology modelling. Methods: Nine different datasets were built, one for each protein (from protein C to non-structural protein 4) and the last one for the complete genome. Selective pressure and homology modelling analyses were applied. Results: Two main clades (A and B) were pointed in the maximum likelihood tree. The clade A included five Brazilian sequences sampled from 1955 to 2015. The Brazilian sequence sampled in 2014 significantly clustered with the Haitian sequence sampled in 2015. The clade B included the remaining 27 sequences sampled in the Central and Southern America from 1957 to 2013. Selective pressure analysis revealed several sites under episodic diversifying selection in envelope surface glycoprotein E1, non-structural protein 1 and non- structural protein 3 with a posterior probability P≤0.01. Homology modelling showed different sites modified by selective pressure and some protein-protein interaction sites at high interaction propensity. Conclusion: Maximum likelihood analysis confirmed the Mayaro virus previous circulation in Haiti and the successful spread to the Caribbean and USA. Selective pressure analysis revealed a strong presence of negatively selected sites, suggesting a probable purging of deleterious polymorphisms in functional genes. Homology model showed the position 31, under selective pressure, located in the edge of the ADP-ribose binding site predicting to possess a high potential of protein-protein interaction and suggesting the possible chance for a protective vaccine, thus preventing Mayaro virus urbanization as with Chikungunya virus.

Evolutionary characteristics and positive selection site of hepatitis C virus isolated in intravenous drug users in Pudong new district, Shanghai / 中华流行病学杂志

Objective To understand the genotypes of hepatitis C virus (HCV) circulating in intravenous drug users (IDUs) in Pudong new district,Shanghai,and explore the population growth and selection pressure of the HCV strains isolated.Methods A total of 200 serum specimens sampled from IDUs in local methadone maintenance treatment clinic in Pudong were used for amplification of a HCV NS5B 377-nt partial sequence.Mean evolutionary rate and effective number of infections were estimated based on the 377-nt partial sequences of the HCV strains isolated from IDUs and isolated contemporarily from local voluntary blood donors,men who have sex with men and reported hepatitis C cases by using BEAST software.Selection pressure sites were identified with online Datamonkey software for subsequent comparison with direct-acting antiviral (DAA) drug binding sites.Results A total of 39 (19.5％) serum specimens were positive for HCV RNA.The genotypes were determined based on the HCV NS5B 377-nt partial sequences as follows:subtype 3a (n=14),3b (n=13),lb (n=7),6a (n=4) and 6n (n=1).The partial sequences of the HCV strains isolated in IDUs shared high homology with the sequences of the HCV strains isolated in other populations.The Bayesian Skyline Plot indicated that the estimated infections with HCV subtype 1b increased exponentially during the 1990s,whereas that of subtypes 3a and 3b increased slowly since the mid-1990s.In the NS5B 377-nt partial sequences of the HCV strains isolated in IDUs,there were two positive selection sites and seventy-eight negative selection sites recognized.The mutation rate was as low as 2.2％ in the 377-nt partial sequences corresponding to the known seven DAA drug binding sites.Conclusions HCV subtype 3a and 3b were the predominant genotypes in the IDUs in Pudong.Subtype lb was prevalent in different populations and evolved very rapidly,and more infections might be caused,suggesting further attention to its prevention,control and treatment.Although DAA treatment based on HCV NS5B binding sites targeting local IDUs might be effective,it is still necessary to strengthen the surveillance.

Evolutionary characteristics and positive selection site of hepatitis C virus isolated in intravenous drug users in Pudong new district, Shanghai / 中华流行病学杂志

Objective To understand the genotypes of hepatitis C virus (HCV) circulating in intravenous drug users (IDUs) in Pudong new district,Shanghai,and explore the population growth and selection pressure of the HCV strains isolated.Methods A total of 200 serum specimens sampled from IDUs in local methadone maintenance treatment clinic in Pudong were used for amplification of a HCV NS5B 377-nt partial sequence.Mean evolutionary rate and effective number of infections were estimated based on the 377-nt partial sequences of the HCV strains isolated from IDUs and isolated contemporarily from local voluntary blood donors,men who have sex with men and reported hepatitis C cases by using BEAST software.Selection pressure sites were identified with online Datamonkey software for subsequent comparison with direct-acting antiviral (DAA) drug binding sites.Results A total of 39 (19.5％) serum specimens were positive for HCV RNA.The genotypes were determined based on the HCV NS5B 377-nt partial sequences as follows:subtype 3a (n=14),3b (n=13),lb (n=7),6a (n=4) and 6n (n=1).The partial sequences of the HCV strains isolated in IDUs shared high homology with the sequences of the HCV strains isolated in other populations.The Bayesian Skyline Plot indicated that the estimated infections with HCV subtype 1b increased exponentially during the 1990s,whereas that of subtypes 3a and 3b increased slowly since the mid-1990s.In the NS5B 377-nt partial sequences of the HCV strains isolated in IDUs,there were two positive selection sites and seventy-eight negative selection sites recognized.The mutation rate was as low as 2.2％ in the 377-nt partial sequences corresponding to the known seven DAA drug binding sites.Conclusions HCV subtype 3a and 3b were the predominant genotypes in the IDUs in Pudong.Subtype lb was prevalent in different populations and evolved very rapidly,and more infections might be caused,suggesting further attention to its prevention,control and treatment.Although DAA treatment based on HCV NS5B binding sites targeting local IDUs might be effective,it is still necessary to strengthen the surveillance.

Genetic diversity in Ebola virus: Phylogenetic and in silico structural studies of Ebola viral proteins

OBJECTIVE@#To explore the genetic diversity and the modification of antibody response in the recent outbreak of Ebola Virus.@*METHODS@#Sequences retrieved from public databases, the selective pressure analysis and the homology modeling based on the all protein (nucleoprotein, VP35, VP40, soluble glycoprotein, small soluble glycoprotein, VP30, VP24 and polymerase) were used.@*RESULTS@#Structural proteins VP24, VP30, VP35 and VP40 showed relative conserved sequences making them suitable target candidates for antiviral treatment. On the contrary, nucleoprotein, polymerase and soluble glycoprotein have high mutation frequency.@*CONCLUSIONS@#Data from this study point out important aspects of Ebola virus sequence variability that for epitope and vaccine design should be considered for appropriate targeting of conserved protein regions.

Genetic diversity in Ebola virus: Phylogenetic and in silico structural studies of Ebola viral proteins

Objective: To explore the genetic diversity and the modification of antibody response in the recent outbreak of Ebola Virus. Methods: Sequences retrieved from public databases, the selective pressure analysis and the homology modeling based on the all protein (nucleoprotein, VP35, VP40, soluble glycoprotein, small soluble glycoprotein, VP30, VP24 and polymerase) were used. Results: Structural proteins VP24, VP30, VP35 and VP40 showed relative conserved sequences making them suitable target candidates for antiviral treatment. On the contrary, nucleoprotein, polymerase and soluble glycoprotein have high mutation frequency. Conclusions: Data from this study point out important aspects of Ebola virus sequence variability that for epitope and vaccine design should be considered for appropriate targeting of conserved protein regions.

Classification and evolutionary analysis of pollen allergens / 中华微生物学和免疫学杂志

Objective To classify all the plant pollen allergens, each allergen sequence available was compared with protein family database. After that, the appearance and taxonomic distribution of each protein family could be known. When made reference to evolutionary analysis, a regular rule of the distribu-tion of all plant pollen allergens could be concluded. Methods Protein family memberships of each allergen were assigned by comparing the sequences with the Pfam database. Representative members of the most a-bundant pollen allergen families were compared with the Uniprot database using the BLAST server. Acces-sion number of all the interesting homologous could be obtained and all the sequence information could be ac-quired by Batch Entrez. Finally, the evolutionary trees were drawn with the help of MEGA4.0 software. Re-sults One hundred and sixty-eight pollen allergens were classified into 26 protein families. Profilins, pollen _allerg_1 and EF hands constituted the most abundant pollen allergen families. Profilins and EF hands oc-curred in almost all allergenic plant families, whereas allergenic Expansins, FAD_binding proteins, Amb_V allergens and Thaumatins were confined to single taxon. Conclusion It is concluded that the highly con-served sequences of allergens families such as Profilin may be one of the most important reasons of the cross reactivities in allergic diseases. The classification of pollen allergens may be helpful to clinical practice and basic research.