Department of Biological Control and Quarantine, Institute of Plant Protection, Władysława Węgorka 20, 60-318, Poznañ, Poland.
All-Russian Institute of Plant Protection, sch. Podbelskogo, 3, 196608, St. Petersburg, Pushkin, Russia.
Parasitol Res. 2020 Mar;119(3):915-923. doi: 10.1007/s00436-020-06611-9. Epub 2020 Jan 22.
A new species and a new genus of a microsporidium Alternosema bostrichidis isolated from an adult Prostephanus truncatus in Mexico and from three species of the genus Dinoderus in Nigeria are described. The microsporidium is monomorphic, monoxenic, and develops in direct contact with host cell cytoplasm. The infection first appears with thoracic muscles, followed by a generalized invasion of the host. All developmental stages are diplokaryotic. Sporogony is disporoblastic. Mature spores are ovoid. Unfixed spores measure 3.7-4.2 × 2.0-2.6 μm, fixed and stained spores 3.5-5.0 × 2.4-2.8 μm. The polaroplast consists of dense lamellae and rare lamellae. The polar tube is slightly anisofilar, consisting of 11-17 coils, with 9-14 proximal (130 nm in diameter) and 2-3 distal coils (120 nm in diameter) arranged in one layer. Molecular phylogenetic analysis based upon a short portion of small-subunit ribosomal RNA gene (Genbank accession # KP455651) placed the new microsporidium within Liebermannia-Orthosomella lineage, which contains multiple undescribed parasites. In particular, A. bostrichidis showed maximal sequence similarity of 95% to Microsporidium sp. BBRE2 (# FJ755987) from Baikalian Diplacanthus brevispinus (Amphipoda: Acanthogammaridae) and Microsporidium sp. Comp CD Van 2 (# KC111784) from compost and soil in Canada. Frequent, devastating epizootics of laboratory cultures of A. bostrichidis support its potential as a biological control agent of grain borers.
一种新的微孢子虫属 Alternosema bostrichidis 和一个新种，从墨西哥成年 Prostephanus truncatus 和尼日利亚三种 Dinoderus 属昆虫中分离出来。该微孢子虫是单态的、单生的，在与宿主细胞质直接接触的情况下发育。感染首先出现在胸肌，然后是宿主的全身性入侵。所有发育阶段都是双核的。孢子发生是双分裂的。成熟孢子为卵形。未固定的孢子大小为 3.7-4.2×2.0-2.6μm，固定和染色的孢子大小为 3.5-5.0×2.4-2.8μm。极质体由密集的薄片和罕见的薄片组成。极管略带异丝，由 11-17 个线圈组成，有 9-14 个近端线圈（直径 130nm）和 2-3 个远端线圈（直径 120nm），排列在一层。基于小亚基核糖体 RNA 基因（Genbank 登录号 #KP455651）的短片段的分子系统发育分析将新的微孢子虫置于 Liebermannia-Orthosomella 谱系内，该谱系包含多个未描述的寄生虫。特别是，A. bostrichidis 与来自贝加尔湖 Diplacanthus brevispinus（甲壳纲：Acanthogammaridae）的 Microsporidium sp. BBRE2（#FJ755987）和加拿大堆肥和土壤中的 Microsporidium sp. Comp CD Van 2（#KC111784）的序列相似度最高，为 95%。实验室培养的 A. bostrichidis 频繁、严重的爆发支持了它作为谷物蛀虫生物防治剂的潜力。
