Incidence of Wolbachia and Cardinium Endosymbionts in the Osmia Community in Korea

Gilsang Jeong,Kyeongyong Lee,최지영,Seokjo Hwang,박병도,Wontae Kim,최영철,Ingyun Park,Jonggill Kim 한국미생물학회 2009 The journal of microbiology Vol.47 No.1

Sex ratio distorting endosymbionts induce reproductive anomalies in their arthropod hosts. They have recently been paid much attention as firstly texts of evolution of host-symbiont relationships and secondly potential biological control agents to control arthropod pests. Among such organisms, Wolbachia and Cardinium bacteria are well characterized. This study aims at probing such bacteria in the Osmia community to evaluate their potential utilization to control arthropod pests. Among 17 PCR tested species, Osmia cornifrons and a parasitic fly are infected with Wolbachia and a mite species is infected with Cardinium. Phylogenetic tree analyses suggest that horizontal transfer of the bacteria occurred between phylogenetically distant hosts.

Wolbachia Infection Frequency in Some Korean ant Species

Gilsang Jeong,Eunha Ko,Jaeyeon Kang,Jae Chun Choe 한국응용곤충학회 2014 한국응용곤충학회 학술대회논문집 Vol.2014 No.10

The Wolbachia bacterium is one of the best studied reproductive manipulators found in variuos invertebrate taxa. Theoretically it infects two thirds of invertebrates. It is thought to have a huge impact on its hosts’ evolution. The ant is a very successful organism in terrestrial ecosystems especially with its charicteristic sociality. However, the influence of Wolbachia on the animal remains to be paid more attention. This study is to examine Wolbachia infection frequency in some ant species in Korea. The result shows that 9 out of 12 ant species harbor the bacterium. Furthermore, at least two species show polymorphism in their infection status at the colony level. This will be used as a foundation of further study on the interactions between the bacterium and ant species.

Population structure of the invasive black soldier fly, Hermetia illucens (Diptera: Stratiomyidae) in Korea

Gilsang Jeong,Eunjoo Choi,Yonggu Lee,Young-cheol Choi,Sang-beom Lee,Hansu Choi 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.10

The invasive black soldier fly, Hermetia illucens, has been paid much attention as an excellent organic matter decomposer. We conducted the nationwide survey and the population genetic study using a mitochondrial cytochrome C oxidase 1 gene to understand its genetic diversity and distribution pattern in Korea. The results show that it has successfully settled down in South Korea and there are only 10 haplotypes and the populations of the insect are highly differentiated. The results indicate that only few maternal lineages were introduced and their dispersal was restrained due to their short distance flying tendency since their introduction.

Comparative Analysis of rRNA of the Nosema/Vairimorpha Clade: Reconsideration of the ‘true’ Nosema with Mosaic Nature of a Nosema Strain

Gilsang Jeong,Jonggill Kim,Wontae Kim,Youngchul Choi,Kwanho Park,Jiyoung Choi 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.05

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.

Family-wide distribution and recombination of the Wolbachia endosymbiont in Coleopteran insects

Gilsang Jeong,Taehwa Kang,Soojin Hwang,Haechul Park,Youngcheol Choi,Kyoungsang Cho,Wantae Kim,Kwanho Park,Jonggill Kim,Youngbo Lee,Taeman Han,Jiyoung Choi 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.10

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.

Wolbachia, the Eccentric Life Form:from its Fundamentals to Application Potential

Gilsang Jeong 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.05

The Wolbachia bacterium belongs to α-proteobacteria and is one of the most prevalent intracellular endosymbionts of arthropods and nematodes. One theoretical study suggests that the bacterium may infect up to 66% of insect species. Its fundamental biology and potential applications have been paid much attention with its ability to induce 4 distinct reproductive anomalies and other modifications of its various hosts. The four reproductive anomalies include, i) cytoplasmic incompatibility, where embryonic death results from the cross between an uninfected female and an infected male, ii) feminization, where an infected egg with male genetic background develops into an infected functional female, iii) male killing, where infected eggs with male genetic background dies in their early developmental stage, iv) parthenogenesis, exclusively where, in organisms with haplodiploid sex determination, an infected unfertilized egg develops into an infected female. All these reproductive anomalies, except cytoplasmic incompatibility, cause female biased sex ratio because females can descend cytoplasm to the next generation where the bacterium can reside. Furthermore, these have nothing to do with hosts’ evolutionary interests but only with the bacterial evolutionary interests (i.e. its prosperity). In this sense, the bacterium is one of the pronounced examples of selfish genetic elements. Recent researches also focus on some novel phenomena other than these reproductive anomalies mentioned above. We will review recent advances in general biology of the bacterium, its impacts on host life history, the reproductive anomalies and cellular mechanisms underlying them and potential utilization of the bacterium for better agricultural and medical environments.

Sharing of an endosymbiont in sap-feeding insects with the emphasis of Lycorma delicatula

Gilsang Jeong,Eunjoo Choi,Jaeha Ahn,Yikweon Jang,Hansu Choi 한국응용곤충학회 2010 한국응용곤충학회 학술대회논문집 Vol.2010 No.10

evolution of multicellular organisms. Especially in insects, a large amount of bacterial symbionts are illustrated. Among the insect taxonomic group, sap feeding insects, mostly Heteroptera, that feeds on poor nutrient sources from plants, have developed special organs where symbiotic bacteria can reside. The bacteria mainly provide the host insects with some essential amino acids. This has built evolutionarily unbreakable tie between the symbionts and the their hosts. Here we present an obligate symbiont from Lycorma delicatula (Heteroptera: Fulgoridae) being thought to invade the Korean penninsula recently. Based on the partial 16s rRNA gene sequence, the symbiotic bacterium is identified as Cadidatus Sulcia mullleri. The Genbank data indicates that the bacterium is found in various heteropteran families. This may imply the acquisition of the bacterium precedes the hosts' divergence, though there is an alternative postulation. We discuss its distribution in the sap-feeding insects and potential role on survival of L. delicatula and paratransgenetic application of the bacterium in controlling L. delicatula.

The Wolbachia bacterial density determines the sex in Trichogramma kaykai (Hymenoptera: Trichogrammatidae)

Gilsang Jeong,James Russell,Richard Stouthamer 한국응용곤충학회 2011 한국응용곤충학회 학술대회논문집 Vol.2011 No.05

The Wolbachia bacterium is known to induce reproductive anomalies in various insect taxa such as cytoplasmic incompatibility, feminization, male killing and parthenogenesis. It is hypothesized that the degree of reproductive anomalies is dependent on the bacterial infection density. In this study, we attempted to test the hypothesis using the tiny egg wasp, Trichogramma kaykai that has served as the model system of parthenogenesis where an unfertilized egg develops into a female due to the bacterial infection. So far this is only found in haplodiploid organisms. The results show that 1) as mothers aged, they started producing male offspring, 2) the sex ratio was negatively correlated with the bacterial infection density, 3) female offspring were more than six times heavily infected with Wolbachia than male offspring in the species. In conclusion, female offspring production, parthenogenesis, is as a function of the Wolbachia bacterial density in this species.

Wolbachia infection in the Loxoblemmus complex (Orthoptera: Gryllidae) in Korea

Jeong, Gilsang,Ahn, Jaeha,Jang, Yikweon,Choe, Jae Chun,Choi, Hansu 한국응용곤충학회 2012 Journal of Asia-Pacific Entomology Vol. No.

The Wolbachia bacterium is one of the most prevalent intracellular symbionts of invertebrates, particularly insects. This bacterium induces four distinct reproductive anomalies such as cytoplasmic incompatibility, feminization, male killing, and parthenogenesis of its hosts. Here we report that three closely related cricket species, Loxoblemmus doenitzi, L. campestris, and L. equestris can become infected with Wolbachia. Based on the 16s rRNA sequences, all three species were single infections. However, Wolbachia infecting L. campestris showed diverse Wolbachia surface protein gene sequences resembling multiple infections. In addition, all Wolbachia strains in the three host species harbored the Wolbachia specific bacteriophage.

Wolbachia in Beetle species in Korea

Gilsang Jeong,Soyeon Park,Taeman Han,Heachul Park 한국응용곤충학회 2019 한국응용곤충학회 학술대회논문집 Vol.2019 No.04

The Wolbachia bacterium, one of the most prevalent endosymbiotic bacteria, is known to induce reproductive anomalies in various invertebrate taxa. We investigated Wolbachia infection frequency in 203 Coleopteran insects collected from Korea. Among them 26 species (12.8%) across families proved to harbor Wolbachia. The phylogenetic trees of two Wolbachia specific genes imply that there have been complex horizontal gene transfers and recombination events within and between divergent Wolbachia subgroups. Interestingly, we also find that the infection frequency is noticeably low and incongruent at the family level when compared to other literature cases of Wolbachia infection in beetle species.