Specificity and genetic diversity of xylose-fermenting Scheffersomyces yeasts associated with small blue stag beetles of the genus Platycerus in East Asia
Specificity and genetic diversity of xylose-fermenting Scheffersomyces yeasts associated with small blue stag beetles of the genus Platycerus in East Asia
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DOI：
10.1080/00275514.2017.1382648
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发表时间：
2017-07
期刊：
影响因子：
2.8
通讯作者：
Masahiko Tanahashi;Jongkuk Kim;Kana Watanabe;T. Fukatsu;K. Kubota
中科院分区：
文献类型：
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作者：
Masahiko Tanahashi;Jongkuk Kim;Kana Watanabe;T. Fukatsu;K. Kubota
摘要在昆虫-真菌关系中，木糖发酵的Schlosome-sobarbacillus酵母因其利用木材半纤维素的潜力以及与各种食木昆虫的关系而闻名。然而，它们对宿主昆虫的特异性或宿主物种内的菌株水平多样性尚未明确阐明。在昆虫科中，幼虫通常以腐烂的木材为食，成年雌性在腹部尖端附近一直拥有一个真菌储存器官，称为真菌囊。利用基因间间隔区（IGS）作为遗传标记，研究了东亚地区绿僵菌共生体与绿僵虫属（鞘翅目：绿僵虫科）小型蓝僵虫之间的宿主-共生体关系。根据nrDNA 26 S和ITS序列分析，从韩国的P. hongwonpyoi、日本的P. acuticollis和P. delicatulus等3种扁角木属植物的雌性菌囊中分离的酵母菌株均与Schlosomalosegobiensis亲缘关系近，且没有发现菌株间的序列差异。然而，IGS区域显示出明显的遗传分化内的酵母共生体的P. hongwonpyoi，以及韩国和日本的Platycerus物种之间。在IGS序列中，核苷酸替换主要分布在IGS 1的整个延伸段和IGS 2的前半部分，而核苷酸缺口则位于IGS 1和IGS 2的中部。尽管扁角甲虫与S.在东亚的segobiensis中，酵母共生体的地球系统发育分化模式与昆虫宿主的不一致。
ABSTRACT Among insect-fungus relationships, xylose-fermenting Scheffersomyces yeasts are well known for their potential in utilizing wood hemicelluloses and their association with various wood-feeding insects. However, their specificity to host insects or strain-level diversity within host species has not been clearly elucidated. In the insect family Lucanidae, larvae usually feed on decaying wood, and adult females consistently possess a fungus-storage organ, called the mycangium, near the abdominal tip. Here the authors investigated host-symbiont relationships between Scheffersomyces yeast symbionts and small blue stag beetles of the genus Platycerus (Coleoptera: Lucanidae) in East Asia by using intergenic spacer (IGS) region as a genetic marker. All yeast strains isolated from the female mycangium of three Platycerus species, P. hongwonpyoi from Korea and P. acuticollis and P. delicatulus from Japan, were allied to Scheffersomyces segobiensis based on the sequences of the nrDNA 26S and internal transcribed spacer (ITS), in which no sequence difference was observed among those strains. However, IGS regions showed clear genetic differentiation within the yeast symbionts of P. hongwonpyoi, as well as between those of Korean and Japanese Platycerus species. In the IGS sequences, nucleotide substitutions were mainly distributed in the whole stretch of IGS1 and the anterior half of IGS2, whereas nucleotide gaps were localized at IGS1 and the middle of IGS2. Despite the conserved association between the Platycerus beetles and the specific strains of S. segobiensis in East Asia, geophylogenetic divergence patterns of the yeast symbionts were not concordant with those of the insect hosts.