Dynamic evolution of diaphorin biosynthetic genes against a background of genome conservation in Profftella
- 1Toyohashi University of Technology
Abstract
The Asian citrus psyllid Diaphorina citri (Insecta: Hemiptera), a major agricultural pest, harbors the unusual obligate bacterial symbiont "Candidatus Profftella armatura" (Profftella), which is intimately integrated with its host yet devotes a remarkably large proportion of its highly reduced genome to the production of diaphorin, a bioactive polyketide. To gain insight into the evolution of this distinctive symbiont, we determined the genomes of Profftella and the co-resident nutritional symbiont "Candidatus Carsonella ruddii" (Carsonella) from Diaphorina lycii and compared them with previously characterized counterparts from D. citri and D. cf. continua. The Profftella and Carsonella chromosomes from D. lycii were 471 and 174 kb, respectively, and Profftella harbored an 8-kb plasmid. Genome organization and gene content were highly conserved across the three lineages. The diaphorin biosynthetic system likewise retained its overall organization, consistent with an important role for diaphorin in the Diaphorina symbiotic system. Remarkably, however, pronounced lineage-specific structural variation was observed in diaphorin synthases DipP and DipT, encoded by two of the 20 diaphorin biosynthetic genes. These synthases contained three extensively amplified tandem arrays of acyl carrier protein (ACP) domains that carry growing polyketide intermediates, with up to seven copies compared with one or two at corresponding positions in the related pederin synthases. All three regions of tandem ACP repeats showed copy-number variation among the Profftella lineages. This variation indicates that ACP amplification remains evolutionarily dynamic despite the otherwise highly constrained symbiotic genome. Together, our findings show that even highly integrated obligate symbionts retain evolutionary flexibility in specialized functional systems.
Related
- Diaphorin induces extensive transcriptional remodeling of translation, transport, metabolism, and stress responses in Escherichia coli
- The diversity, evolution, and conservation of African plants
- Markers of biosynthetic innovation in the Cyanobacteria
- Inhibitory effects of propyl paraben, citral, and gallic acid on the growth, patulin biosynthesis, and patulin biosynthetic gene expression of Penicillium paneum OM1
- Effect of PBAN on Pheromone Production and Biosynthetic Pathway of the Major Sex Pheromone Component of Proeulia auraria Clarke (Lepidoptera: Tortricidae)
BibTeX
@misc{yasuda2026dynamic,
title = {{Dynamic evolution of diaphorin biosynthetic genes against a background of genome conservation in Profftella}},
author = {Y. Yasuda and J. Piel and I. Malenovsky and I. Gjonov and Y. Hirose and A. Nakabachi},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.30.762998},
url = {https://www.biorxiv.org/content/10.64898/2026.10.30.762998v1},
note = {CC BY-NC-ND},
}
RIS
TY - UNPB
TI - Dynamic evolution of diaphorin biosynthetic genes against a background of genome conservation in Profftella
AU - Y. Yasuda
AU - J. Piel
AU - I. Malenovsky
AU - I. Gjonov
AU - Y. Hirose
AU - A. Nakabachi
PY - 2026
DA - 2026/10/30
PB - bioRxiv
DO - 10.64898/2026.10.30.762998
UR - https://www.biorxiv.org/content/10.64898/2026.10.30.762998v1
AB - The Asian citrus psyllid Diaphorina citri (Insecta: Hemiptera), a major agricultural pest, harbors the unusual obligate bacterial symbiont "Candidatus Profftella armatura" (Profftella), which is intimately integrated with its host yet devotes a remarkably large proportion of its highly reduced genome to the production of diaphorin, a bioactive polyketide. To gain insight into the evolution of this distinctive symbiont, we determined the genomes of Profftella and the co-resident nutritional symbiont "Candidatus Carsonella ruddii" (Carsonella) from Diaphorina lycii and compared them with previously characterized counterparts from D. citri and D. cf. continua. The Profftella and Carsonella chromosomes from D. lycii were 471 and 174 kb, respectively, and Profftella harbored an 8-kb plasmid. Genome organization and gene content were highly conserved across the three lineages. The diaphorin biosynthetic system likewise retained its overall organization, consistent with an important role for diaphorin in the Diaphorina symbiotic system. Remarkably, however, pronounced lineage-specific structural variation was observed in diaphorin synthases DipP and DipT, encoded by two of the 20 diaphorin biosynthetic genes. These synthases contained three extensively amplified tandem arrays of acyl carrier protein (ACP) domains that carry growing polyketide intermediates, with up to seven copies compared with one or two at corresponding positions in the related pederin synthases. All three regions of tandem ACP repeats showed copy-number variation among the Profftella lineages. This variation indicates that ACP amplification remains evolutionarily dynamic despite the otherwise highly constrained symbiotic genome. Together, our findings show that even highly integrated obligate symbionts retain evolutionary flexibility in specialized functional systems.
ER -