Fig. 4: Genomic and cellular features of highly reduced Vidania symbionts.

A The representation of the smallest Vidania genomes from three planthopper superfamilies showcases their strongly reduced gene sets. B The alignment of the two smallest Vidania genomes, which evolved independently from an ancestor approximately three times their size, shows striking convergence in their organization and content. Due to the low sequence similarity among genomes, the alignment plot is based on the positions of annotated genes. C The morphology and ultrastructure of bacteriome tissue inhabited by Vidania with the smallest genomes differ from previously studied planthoppers by particularly high mitochondrial density - as exemplified by Malenia bosnica bacteriome and its tiny-genome Vidania VFMALBOS using fluorescence (C1), light (C2), and transmission electron microscopy (C3). The microphotographs were selected as representative from among multiple images obtained for ten adult individuals of M. bosnica. bn - bacteriocyte nucleus, m - mitochondrion, V - Vidania cell; C1, C2 − 10 µm, C3 − 1 µm.