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A ctinobacteria as essential symbionts in firebugs and cotton stainers ( H emiptera, P yrrhocoridae)
Author(s) -
Salem Hassan,
Kreutzer Elisabeth,
Sudakaran Sailendharan,
Kaltenpoth Martin
Publication year - 2013
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.12001
Subject(s) - biology , mutualism (biology) , symbiosis , host (biology) , commensalism , niche , bacteria , gut flora , insect , ecology , zoology , botany , genetics , immunology
Summary A ctinobacteria engage in defensive symbioses with several insect taxa, but reports of nutritional contributions to their hosts have been exceptionally rare. Cotton stainers ( D ysdercus fasciatus ) and red firebugs ( P yrrhocoris apterus ) (both H emiptera, P yrrhocoridae) harbour the actinobacterial symbionts C oriobacterium glomerans and G ordonibacter sp. as well as F irmicutes ( C lostridium sp. and L actococcus sp.) and P roteobacteria ( K lebsiella sp. and a R ickettsiales bacterium) in the M 3 region of their mid‐gut. We combined experimental manipulation with community‐level analyses to elucidate the function of the gut symbionts in both pyrrhocorid species. Elimination of symbionts by egg‐surface sterilization resulted in significantly higher mortality and reduced growth rates, indicating that the microbial community plays an important role for host nutrition. Fitness of symbiont‐deprived bugs could be completely restored by re‐infection with the original microbiota, while reciprocal cross‐infections of microbial communities across both pyrrhocorid species only partially rescued fitness, demonstrating a high degree of host–symbiont specificity. Community‐level analyses by quantitative PCR s targeting the dominant bacterial strains allowed us to link the observed fitness effects to the abundance of the two actinobacterial symbionts. The nutritional mutualism with A ctinobacteria may have enabled pyrrhocorid bugs to exploit M alvales seeds as a food source and thereby possibly allowed them to occupy and diversify in this ecological niche.