Shekar Malathi, Pradeep Balakrishnan, Karunasagar Indrani
Department of Fishery Microbiology, College of Fisheries, Karnataka Veterinary, Animal and Fisheries Sciences University, Mangalore, 575 002 India.
Indian J Virol. 2012 Sep;23(2):175-83. doi: 10.1007/s13337-012-0078-z. Epub 2012 Aug 14.
White spot syndrome virus (WSSV) is a pathogen that has emerged globally affecting shrimp populations. Comparison of WSSV genome have shown the virus to share a high genetic similarity except for a few variable genomic loci that has been employed as markers in molecular epidemiology studies for determining the origin, evolution and spread in different geographical regions. Molecular genotyping of WSSV are based on genomic deletions associated with ORF23/24 and ORF14/15 variable regions and the three variable number of tandem repeat regions, ORF75, ORF94 and ORF125. Studies show the prevalence of several genotypes for WSSV with particular genotypes being more prevalent than others in a given geographical area. Deletions associated with ORF23/24 and ORF14/15 variable regions have proven to be of evolutionary significance. Fitness and virulence studies on different genotypes of WSSV suggest that all the strains of WSSV are equally virulent, but the one with smaller genomic size is the fittest. Studies also have shown that mixed genotype infection of WSSV correlates with lower disease outbreaks. This review focuses on the genotyping studies that were undertaken in elucidating WSSV evolution and epidemiology.
白斑综合征病毒（WSSV）是一种在全球出现的影响虾类种群的病原体。对WSSV基因组的比较表明，除了一些可变基因组位点外，该病毒具有高度的遗传相似性，这些位点已被用作分子流行病学研究中的标记，用于确定其在不同地理区域的起源、进化和传播。WSSV的分子基因分型基于与ORF23/24和ORF14/15可变区以及三个可变串联重复序列区域（ORF75、ORF94和ORF125）相关的基因组缺失。研究表明，WSSV存在多种基因型，在特定地理区域中，某些基因型比其他基因型更为普遍。与ORF23/24和ORF14/15可变区相关的缺失已被证明具有进化意义。对WSSV不同基因型的适应性和毒力研究表明，所有WSSV毒株的毒力相同，但基因组较小的毒株适应性最强。研究还表明，WSSV的混合基因型感染与较低的疾病暴发相关。本综述重点关注为阐明WSSV进化和流行病学而进行的基因分型研究。
