摘要
No ascovirus isolated from China has been sequenced so far. Therefore, in this study, we aimed to sequence the genome of Heliothis virescens ascovirus 3h(Hv AV-3h) using the 454 pyrosequencing technology. The genome was found to be 190,519-bp long with a G+C content of 45.5%. We also found that it encodes 185 hypothetical open reading frames(ORFs) along with at least 50 amino acids, including 181 ORFs found in other ascoviruses and 4 unique ORFs. Gene-parity plots and phylogenetic analysis revealed a close relationship between Hv AV-3h and three other Hv AV-3a strains and a distant relationship with Spodoptera frugiperda ascovirus 1a(Sf AV-1a), Trichoplusia ni ascovirus 6a(Tn AV-6a), and Diadromus pulchellus ascovirus 4a(Dp AV-4a). Among the 185 potential genes encoded by the genome, 44 core genes were found in all the sequenced ascoviruses. In addition, 25 genes were found to be conserved in all ascoviruses except Dp AV-4a.In the Hv AV-3h genome, 24 baculovirus repeat ORFs(bros) were present, and the typical homologous repeat regions(hrs) were absent. This study supplies information important for understanding the conservation and functions of ascovirus genes as well as the variety of ascoviral genomes.
No ascovirus isolated from China has been sequenced so far. Therefore, in this study, we aimed to sequence the genome of Heliothis virescens ascovirus 3h （HvAV-3h） using the 454 pyrosequencing technology. The genome was found to be 190,519-bp long with a G＋C content of 45.5%. We also found that it encodes 185 hypothetical open reading frames （ORFs） along with at least 50 amino acids, including 181 ORFs found in other ascoviruses and 4 unique ORFs. Gene-parity plots and phylogenetic analysis revealed a close relationship between HvAV-3h and three other HvAV-3a strains and a distant relationship with Spodoptera frugiperda ascovirus la （SfAV-la）, Trichoplusia ni ascovirus 6a （TnAV-6a）, and Diadromus pulchellus ascovirus 4a （DpAV-4a）. Among the 185 potential genes encoded by the genome, 44 core genes were found in all the sequenced ascoviruses. In addition, 25 genes were found to be conserved in all ascoviruses except DpAV-4a. In the HvAV-3h genome, 24 baculovirus repeat ORFs （bros） were present, and the typical homologous repeat regions （hrs） were absent. This study supplies information important for understanding the conservation and functions of ascovirus genes as well as the variety of ascoviral genomes.
基金
supported partly by the National Natural Science Foundation of China (No. 31371995 and 31621061)
the Strategic Priority Research Program of the Chinese Academy of Sciences (grant XDB11030400)
STS Project of the Chinese Academy of Sciences (grant KFJ-SW-STS143-3)
the Hunan Provincial Natural Science Foundation for Distinguished Young Scholar of China (14JJ1023)
