Detailed investigation of the sequential pathological changes in silkworm larvae infected with Bombyx densovirus type 1
Detailed investigation of the sequential pathological changes in silkworm larvae infected with Bombyx densovirus type 1
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DOI：
10.1016/j.jip.2012.12.005
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发表时间：
2013-03-01
影响因子：
3.4
通讯作者：
Kadono-Okuda, Keiko
中科院分区：
文献类型：
--
作者：
Ito, Katsuhiko;Kidokoro, Kurako;Kadono-Okuda, Keiko
家蚕致密病毒1型(BmDNV-1)是引起家蚕软化病的病原。BmDNV-1只在幼虫中肠上皮柱状细胞的细胞核中增殖。尽管到目前为止已经报道了一些使用抗BmDNV-1抗体的免疫组织化学研究，但BmDNV-1感染幼虫的连续病理变化尚未完全阐明。本文对BmDNV-1感染幼虫的病理特征和BmDNV-1的传播进行了连续观察。用新脱皮的4龄幼虫进行的口腔感染实验表明，幼虫在感染后9天开始死亡，其余的幼虫在感染后10天死亡。组织学观察显示，从4dpi开始，中肠细胞发生表型变化，9dpi时中肠结构完全破坏。两个BmDNV-1基因的定量RT-PCR结果表明，BmDNV-1从4dpi开始繁殖，并逐渐增加，直到幼虫死亡。这些表达模式与在病毒感染的中肠细胞中观察到的组织学变化显著相关。此外，利用不同发育阶段的幼虫进行的生物测定清楚地表明，该病毒的致病性不依赖于幼虫的阶段或蜕皮过程。(C)2012 Elsevier Inc.保留所有权利。
Bombyx mori densovirus type 1 (BmDNV-1) is a pathogen causing flacherie disease in silkworms. BmDNV-1 multiplies only in the nuclei of the columnar cells of larval midgut epithelium. Although several immunohistochemical studies using anti-BmDNV-1 antibody have been reported to date, sequential pathological changes in BmDNV-1-infected larvae have not been completely elucidated. In this paper, sequential investigations were performed on the pathological features of BmDNV-1-infected larvae and BmDNV-1 propagation. Oral infection experiments using newly ecdysed 4th instar larvae revealed that the larvae began to die 9 days post infection (dpi), and the remaining died 10 dpi. Histological observations revealed phenotypic alterations in the midgut cells from 4 dpi, and complete disruption of the midgut structure at 9 dpi. Quantitative RT-PCR of two BmDNV-1 genes indicated that BmDNV-1 began to propagate from 4 dpi, and gradually increased until the larvae died. These expression patterns revealed marked correlation with the histological changes observed in the virus-infected midgut cells. Moreover, bioassays using larvae at various developmental stages clearly indicated that the pathogenicity of this virus is not dependent on the larval stage or the molting process. (C) 2012 Elsevier Inc. All rights reserved.