http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Kim, J.K.,Lee, J.B.,Jang, H.A.,Han, Y.S.,Fukatsu, T.,Lee, B.L. Pergamon Press ; Elsevier Science 2016 DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY Vol.64 No.-
<P>Valuable insect models have tremendously contributed to our, understanding of innate immunity and symbiosis. Bean bug, Riptortus pedestris, is a useful insect symbiosis model due to harboring cultivable monospecific gut symbiont, genus Burkholderia. Bean bug is a hemimetabolous insect whose immunity is not well-understood. However, we recently identified three major antimicrobial peptides of Riptortus and examined the relationship between gut symbiosis and host immunity. We found that the presence of Burkholderia gut symbiont positively affects Riptortus immunity. From studying host regulation mechanisms of symbiont population, we revealed that the symbiotic Burkholderia cells are much more susceptible to Riptortus immune responses than the cultured cells. We further elucidated that the immune susceptibility of the Burkholderia gut symbionts is due to the drastic change of bacterial cell envelope. Finally, we show that the immune-susceptible Burkholderia symbionts are able to prosper in host owing to the suppression of immune responses of the symbiotic midgut. (C) 2016 Elsevier Ltd. All rights reserved.</P>
Kim, J.K.,Han, S.H.,Kim, C.H.,Jo, Y.H.,Futahashi, R.,Kikuchi, Y.,Fukatsu, T.,Lee, B.L. Pergamon Press ; Elsevier Science 2014 DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY Vol.43 No.1
The majority of insects possess symbiotic bacteria. Since symbiont titers can affect host phenotypes of biological importance, host insects are expected to evolve some mechanisms for regulating symbiont population. Here we report that, in the Riptortus-Burkholderia gut symbiosis, titers of the beneficial symbiont transiently decrease at the pre-molt stages in host development. This molting-associated suppression of the symbiont population is coincident with the increase of antimicrobial activity in the symbiotic midgut, which is observed in both symbiotic and aposymbiotic insects. Two genes, pyrrhocoricin-like antimicrobial peptide and c-type lysozyme, exhibit significantly increased expression in the symbiotic midgut at the pre-molt stages. These results suggest that the molting-associated up-regulation of antimicrobial activity in the symbiotic midgut represents a physiological mechanism of the host insect to regulate symbiosis, which is presumably for defending molting insects against injury and infection and/or for allocating symbiont-derived energy and resources to host molting.
Lee, J.B.,Park, K.E.,Lee, S.A.,Jang, S.H.,Eo, H.J.,Jang, H.A.,Kim, C.H.,Ohbayashi, T.,Matsuura, Y.,Kikuchi, Y.,Futahashi, R.,Fukatsu, T.,Lee, B.L. PERGAMON 2017 DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY Vol. No.
<P>Recent studies have suggested that gut symbionts modulate insect development and reproduction. However, the mechanisms by which gut symbionts modulate host physiologies and the molecules involved in these changes are unclear. To address these questions, we prepared three different groups of the insect Riptortus pedestris: Burkholderia gut symbiont-colonized (Sym) insects, Burkholderia-non-colonized (Apo) insects, and Burkholderia-depleted (Sym(Burk-)) insects, which were fed tetracycline. When the hemolymph proteins of three insects were analyzed by SDS-PAGE, the hexamerin-alpha, hexamerin-beta and vitellogenin-1 proteins of Sym-adults were highly expressed compared to those of Apo- and Sym-(Burk-)-msects. To investigate the expression patterns of these three genes during insect development, we measured the transcriptional levels of these genes. The hexamerin-beta gene was specifically expressed at all nymphal stages, and its expression was detected 4-5 days earlier in Sym-insect nymphs than that in Apo- and Sym(Burk-)-insects. However, the hexamerin-alpha and vitellogenin-1 genes were only expressed in adult females, and they were also detected 6-7 days earlier and were 2-fold higher in Sym-adult females than those in the other insects. Depletion of hexamerin-beta by RNA interference in 2nd instar Sym-nymphs delayed adult emergence, whereas hexamerin-alpha and vitellogenin-1 RNA interference in 5th instar nymphs caused loss of color of the eggs of Sym-insects. These results demonstrate that the Burkholderia gut symbiont modulates host development and egg production by regulating production of these three hemolymph storage proteins. (C) 2016 Elsevier Ltd. All rights reserved.</P>