Gammaproteobacteria as essential primary symbionts in the striped shield bug, Graphosoma Lineatum (Hemiptera: Pentatomidae)

• Published in: Scientific reports Vol. 6; no. 1; p. 33168
• Main Authors: Karamipour, Naeime, Fathipour, Yaghoub, Mehrabadi, Mohammad
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 09-09-2016; Nature Publishing Group
• Subjects: 14/63; 45/23; 45/29; 45/77; 631/326/2565/547; 631/601/1466; Animals; Bacterial Proteins - genetics; Chaperonin 60 - genetics; Eggs; Electron microscopy; Erwinia - classification; Erwinia - physiology; Fecundity; Hemiptera - microbiology; Humanities and Social Sciences; Longevity; multidisciplinary; Offspring; Pantoea - classification; Pantoea - physiology; Phylogenetics; Phylogeny; Polymerase chain reaction; Ribonucleic acid; RNA; RNA, Bacterial - genetics; RNA, Ribosomal, 16S - genetics; Science; Sterilization; Symbionts; Symbiosis - physiology
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep33168

Many members of suborder Heteroptra harbor heritable symbiotic bacteria. Here we characterize the gut symbiotic bacterium in
Graphosoma lineatum
(Hemiptera: Pentatomidae) by using molecular phylogeny, real-time PCR analysis as well as light and electron microscopy observations. The microscopy observations revealed the presence of a large number of rod-shaped bacterial cells in the crypts. A very high prevalence (98 to 100%) of the symbiont infection was found in the insect populations that strongly supports an intimate association between these two organisms. Real-time PCR analysis also showed that the Gammaproteobacteria dominated the crypts. The sequences of
16sr RNA
and
groEL
genes of symbiont showed high levels of similarity (93 to 95%) to
Pantoea agglomeranse
and
Erwinia herbicola
Gammaproteobacteria. Phylogenetic analyses placed
G. lineatum
symbiont in a well-defined branch, divergent from other stink bug bacterial symbionts. Co-evolutionary analysis showed lack of host-symbiont phylogenetic congruence. Surface sterilization of eggs resulted in increased pre-adult stage in the offspring (aposymbionts) in comparison to the normal. Also, fecundity, longevity, and adult stage were significantly decreased in the aposymbionts. Therefore, it seems that the symbiont might play a vital function in the host biology, in which host optimal development depends on the symbiont.