Instituto de Agrobiotecnología, CSIC, Gobierno de Navarra, 31192 Mutilva Baja, Navarra, Spain.
J Invertebr Pathol. 2012 Nov;111(3):260-3. doi: 10.1016/j.jip.2012.08.013. Epub 2012 Sep 7.
A Nicaraguan population of Spodoptera frugiperda multiple nucleopolyhedrovirus, SfMNPV-NIC, includes fast-killing genotypes with deletions in the egt region. Four bacmid based recombinants were constructed to determine the role of egt in this phenotype. SfdelF bacmid encompassed the deletion found in the NIC-F genotype. Sfdel3AP2 bacmid was constructed using the deletion reported in SfMNPV-3AP2 (Missouri, fast-killing isolate), whereas Sfdelegt and Sfdel27 bacmids lacked the single genes egt and the adjacent sf27 gene, respectively. No significant differences were observed in occlusion body (OB) concentration-mortality metrics (LC(50) values) among the viruses. Larvae infected by NIC-B (a natural genotype with the largest genome), Sfbac (a bacmid with NIC-B genome) and Sfdel27 survived significantly longer than insects infected by NIC-F, SfdelF, SfMNPV-3AP2, Sfdel3AP2 or Sfdelegt. Fast-killing viruses produced ∼6-13-fold fewer OBs/larva compared to other viruses tested. We conclude that deletion/disruption of egt is responsible for the fast-killing phenotypes of naturally-occurring genotypes in SfMNPV populations from Missouri and Nicaragua.
一种来自尼加拉瓜的夜蛾核多角体病毒（SfMNPV-NIC）种群，包含在 egt 区域缺失的快速致死基因型。构建了四个基于 bacmid 的重组体，以确定 egt 在这种表型中的作用。SfdelF bacmid 包含在 NIC-F 基因型中发现的缺失。Sfdel3AP2 bacmid 是使用在 SfMNPV-3AP2（密苏里州，快速致死分离株）中报道的缺失构建的，而 Sfdelegt 和 Sfdel27 bacmids 分别缺失单个基因 egt 和相邻的 sf27 基因。在包含体（OB）浓度-致死度量（LC（50）值）方面，病毒之间没有观察到显著差异。与感染 NIC-F、SfdelF、SfMNPV-3AP2、Sfdel3AP2 或 Sfdelegt 的昆虫相比，感染 NIC-B（具有最大基因组的天然基因型）、Sfbac（具有 NIC-B 基因组的 bacmid）和 Sfdel27 的幼虫存活时间明显更长。与其他测试的病毒相比，快速致死病毒产生的 OBs/幼虫数量减少了约 6-13 倍。我们得出结论，egt 的缺失/破坏是密苏里州和尼加拉瓜 SfMNPV 种群中自然发生基因型快速致死表型的原因。
