Four intracellular genomes direct weevil biology: Nuclear, mitochondrial, principal endosymbiont, and Wolbachia

作者：Abdelaziz Heddi, Anne-Marie Grenier, Chaqué Khatchadourian, Hubert Charles, P. Nardon · 发表于：Proceedings of the National Academy of Sciences · 年份：1999 · DOI：10.1073/pnas.96.12.6814 · 被引用次数：346 · 研究领域：Insect symbiosis and bacterial influences、Insect and Pesticide Research、Insect-Plant Interactions and Control

Cell physiology in the weevil Sitophilus oryzae is coordinated by three integrated genomes: nuclear, mitochondrial, and the "S. oryzae principal endosymbiont" (SOPE). SOPE, a cytoplasmic bacterium (2 x 10(3) bacteria per specialized bacteriocyte cell and 3 x 10(6) bacteria per weevil) that belongs to the proteobacteria gamma3-subgroup, is present in all weevils studied. We discovered a fourth prokaryotic genome in somatic and germ tissues of 57% of weevil strains of three species, S. oryzae, Sitophilus zeamais, and Sitophilus granarius, distributed worldwide. We assigned this Gram-negative prokaryote to the Wolbachia group (alpha-proteobacteria), on the basis of 16S rDNA sequence and fluorescence in situ DNA-RNA hybridization (FISH). Both bacteria, SOPE and Wolbachia, were selectively eliminated by combined heat and antibiotic treatments. Study of bacteria involvement in this insect's genetics and physiology revealed that SOPE, which induces the specific differentiation of the bacteriocytes, increases mitochondrial oxidative phosphorylation through the supply of pantothenic acid and riboflavin. Elimination of this gamma3-proteobacterium impairs many physiological traits. By contrast, neither the presence nor the absence of Wolbachia significantly affects the weevil's physiology. Wolbachia, disseminated throughout the body cells, is in particularly high density in the germ cells, where it causes nucleocytoplasmic incompatibility. The coexistence of two distinct types of intrac...