Shiloh
Editor, Senior Moderator
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Comparative analysis of full genomic sequences among different genotypes of dengue virus type 3
Although the previous study demonstrated the envelope protein of dengue viruses is under purifying selection pressure, little is known about the genetic differences of full-length viral genomes of DENV-3. In our study, complete genomic sequencing of DENV-3 strains collected from different geographical locations and isolation years were determined and the sequence diversity as well as selection pressure sites in the DENV genome other than within the E gene were also analyzed.
Results: Using maximum likelihood and Bayesian approaches, our phylogenetic analysis revealed that the Taiwanas indigenous DENV-3 isolated from 1994 and 1998dengue/DHF epidemics and one 1999 sporadic case were of the three different genotypes--I, II, and III, each associated with DENV-3 circulating in Indonesia, Thailand and Sri Lanka, respectively. Sequence diversity and selection pressure of different genomic regions among DENV-3 different genotypes was further examined to understand the global DENV-3 evolution.
The highest nucleotide sequence diversity among the fully sequenced DENV-3 strains was found in the nonstructural protein 2A (mean+SD: 5.84+0.54) and envelope protein gene regions (mean+SD: 5.04+0.32). Further analysis found that positive selection pressure of DENV-3 may occur in the non-structural protein 1 gene region and the positive selection site was detected at position 178 of the NS1 gene.
Conclusion: Our study confirmed that the envelope protein is under purifying selection pressure although it presented higher sequence diversity. The detection of positive selection pressure in the non-structural protein along genotype II indicated that DENV-3 originated from Southeast Asia needs to monitor the emergence of DENV strains with epidemic potential for better epidemic prevention and vaccine development.
Author: Chwan-Chuen King, Day-yu Chao, Li-Jung Chien, Gwong-Jeng Chang, Ting-Hsiang Ling, Yin-Chang Wu and Jyh-Hsiung Huang
Credits/Source: Virology Journal 2008, 5:63
Published on: 2008-05-22
Comparative analysis of full genomic sequences among different genotypes of dengue virus type 3
Although the previous study demonstrated the envelope protein of dengue viruses is under purifying selection pressure, little is known about the genetic differences of full-length viral genomes of DENV-3. In our study, complete genomic sequencing of DENV-3 strains collected from different geographical locations and isolation years were determined and the sequence diversity as well as selection pressure sites in the DENV genome other than within the E gene were also analyzed.
Results: Using maximum likelihood and Bayesian approaches, our phylogenetic analysis revealed that the Taiwanas indigenous DENV-3 isolated from 1994 and 1998dengue/DHF epidemics and one 1999 sporadic case were of the three different genotypes--I, II, and III, each associated with DENV-3 circulating in Indonesia, Thailand and Sri Lanka, respectively. Sequence diversity and selection pressure of different genomic regions among DENV-3 different genotypes was further examined to understand the global DENV-3 evolution.
The highest nucleotide sequence diversity among the fully sequenced DENV-3 strains was found in the nonstructural protein 2A (mean+SD: 5.84+0.54) and envelope protein gene regions (mean+SD: 5.04+0.32). Further analysis found that positive selection pressure of DENV-3 may occur in the non-structural protein 1 gene region and the positive selection site was detected at position 178 of the NS1 gene.
Conclusion: Our study confirmed that the envelope protein is under purifying selection pressure although it presented higher sequence diversity. The detection of positive selection pressure in the non-structural protein along genotype II indicated that DENV-3 originated from Southeast Asia needs to monitor the emergence of DENV strains with epidemic potential for better epidemic prevention and vaccine development.
Author: Chwan-Chuen King, Day-yu Chao, Li-Jung Chien, Gwong-Jeng Chang, Ting-Hsiang Ling, Yin-Chang Wu and Jyh-Hsiung Huang
Credits/Source: Virology Journal 2008, 5:63
Published on: 2008-05-22