Hashimoto Yoshifumi, Valles Steven M
Center for Medical, Agricultural and Veterinary Entomology, U.S. Department of Agriculture-Agricultural Research Service, 1600 SW 23rd Drive, Gainesville, FL 32608, USA.
J Invertebr Pathol. 2007 Oct;96(2):156-61. doi: 10.1016/j.jip.2007.04.006. Epub 2007 Apr 29.
Quantitative real-time PCR was employed to measure the Solenopsis invicta virus 1 (SINV-1) load in tissues, individuals, and among colonies of the red imported fire ant, S. invicta Buren. Among tissues examined from SINV-1-infected adults and larvae, the alimentary canal (specifically the midgut) consistently had the highest number of SINV-1 genome copies (91.1 and 99.9%, respectively). Negative staining of a supernatant of the gut homogenate demonstrated the presence of spherical virus particles with a diameter of 30-35 nm, consistent with SINV-1. The number of SINV-1 genome copies in infected larvae and workers from the same queenright colonies were similar to each other. In other words, the infection rate was consistent among both developmental stages. No significant differences were observed in SINV-1 genome copy number among infected colonies sampled during the winter and summer. Although the SINV-1 infection rate of summer-collected mounds was previously shown to be six-times higher than winter-collected mounds, the intra-colony infection rate appears to be unaffected by season. Perhaps less inter-mound interaction during the winter months among S. invicta restricts spread of the virus. A positive correlation between intra-colony infection rate and mean SINV-1 genome copy number per ant was also observed. Based on these results, it is likely that SINV-1 replicates in gut epithelia of S. invicta and virus is shed into the gut lumen where it may be transmitted to nestmates by trophallaxis.
采用定量实时聚合酶链反应（qRT-PCR）来测定入侵红火蚁（Solenopsis invicta Buren）组织、个体及蚁群中红火蚁病毒1（SINV-1）的载量。在对感染SINV-1的成虫和幼虫的组织检测中，消化道（特别是中肠）始终具有最高数量的SINV-1基因组拷贝数（分别为91.1%和99.9%）。肠道匀浆上清液的负染显示存在直径为30 - 35 nm的球形病毒颗粒，与SINV-1一致。来自同一有蚁后的蚁群中，感染的幼虫和工蚁体内SINV-1基因组拷贝数彼此相似。换句话说，两个发育阶段的感染率是一致的。在冬季和夏季采集的感染蚁群中，SINV-1基因组拷贝数未观察到显著差异。尽管先前显示夏季采集的蚁丘中SINV-1感染率比冬季采集的蚁丘高六倍，但蚁群内感染率似乎不受季节影响。也许冬季入侵红火蚁蚁丘间的相互作用较少，限制了病毒传播。还观察到蚁群内感染率与每只蚂蚁的平均SINV-1基因组拷贝数之间呈正相关。基于这些结果，SINV-1很可能在入侵红火蚁的肠道上皮细胞中复制，病毒释放到肠腔中，可能通过交哺行为传播给巢友。
