Taxonomic resolution of the Nosema/Vairimorpah clade has been augmented with DNA sequences of the small subunit (SSU) and large subunit (LSU) ribosomal RNA (rRNA) and the arrangement of SSU and LSU. Based on the two characteristics, the clade is largely divided into two, i.e. 'true' Nosema sub-group and 'non-true' Nosema sub-group within the clade. Our study shows that a novel Nosema species isolated from Pieris rapae has mixed characteristics of the 'true' and non 'true' Nosema sub-group based on the topology of SSU and LSU sequences, and rRNA of the isolate is normally organized. Additionally, the length of ITS can be a diagnostic tool to distinguish 'true' Nosema from non 'true' Nosema in the Nosema/Vairimorpha clade based on its nucleotide length as reported before. To our knowledge, this is the first report of recombination event in the Nosema/Vairimorpha clade.
This study was conducted to investigate insect fauna in the four insect garden sites of Suwon, Yeongyang, Buyeo and Yecheon from 2005 to 2007. Seasonal population size of insects was largest from June to August in all the four sites. In the four sites, Coleopteran insects were dominant followed by Hemiptera and Orthoptera. Unique education/learning programs are successfully run at the insect gardens based on the three geographic types (i.e. urban, mountainous and rural). These activities will help preserve insect biodiversity in the area and visitors better understand life forms such as insects found in the areas.
The Wolbachia bacterium, one of the most prevalent endosymbiotic bacteria, is known to induce reproductive anomalies such as cytoplasmic incompatibility, feminization, male killing and parthenogenesis in various arthropod species. The bacterium is considered to have had huge impacts on hosts' reproductive biology, immunity, evolution, and molecular machineries. Infection surveys on the bacterium have rather been limited to specific taxa that are mainly of economical importance or conducted with randomly collected organisms. Here we investigated infection frequency of Wolbachia in 206 Coleopteran insects collected from Korea. Among them 28 species (13.59%) across families proved to harbor Wolbachia. The phylogenetic trees based on the partial 16s rRNA gene and the partial Wolbachia surface protein (wsp) gene of Wolbachia show that all the Wolbachia strains belong to either Supergroup A or B and Wolbachia evolved independently from its hosts. In addition, the cophylogenetic analysis of the 16s rRNA gene and wsp gene implies that there have been horizontal DNA transfers and recombination events within and between divergent Wolbachia supergroups.
Microsporidia are obligate fungal intracellular parasites of all animal taxa. Among them the genus Nosema (Nosematidae) is known as the most common entomopathogen. Of these parasites, the ribosomal organization is one of the most pronounced molecular characteristics. One type is the normalarrangement of small subunit (SSU)-internal transcribed spacer (ITS)-large subunit (LSU) in the DNA sequence order. The other is the reverse arrangement of LSU-ITS-SSU. The latter is assigned to be the ‘true’ Nosema in the Nosema/Vairimorpha clade. However, we found that the SSU sequence of a strain of Nosema species having the normal arrangement of its rRNA sequence seemed to be more closely related to the ‘true’ Nosemagroup. Consequently we have further analyzed the complete sequence of rRNA. The results imply that there might be arecombination event in its rRNA evolution and/or the strain may form a novel group near the ‘true’ Nosema group. Interestingly both SSU and LSU of the ‘true’ Nosema and others may be under different selection pressure. We have also found that the size of ITS is distinct between the ‘true’ Nosema and other microsporidian species within the Nosema/Vairimorpha clade. This feature should be a useful diagnostic tool to distinguish the ‘true’ Nosema from others in the clade.