{
  "abstract": "Phylum Actinomycetota (syn. Actinobacteriota or Actinobacteria), one of the largest well-studied bacterial phyla, is renowned for complex morphology, non-motility, ecological versatility, and secondary metabolite production. Chemosensory systems (CSS) are among the most sophisticated prokaryotic signal transduction architectures, yet their evolutionary distribution in this phylum remains poorly understood. Here, a comparative genomic analysis of 693 high-quality genomes spanning the phylum resolves the diversity, distribution, and evolutionary trajectories of CSS. Despite extensive genomic complexity and ecological versatility, only 6.9% of genomes encode complete CSS clusters, confined to a subset of lineages within a few classes, indicating lineage-specific retention or loss. In contrast, two-component systems (TCS) are ubiquitously abundant, with hybrid kinases enriched in CSS-deficient classes, suggesting functional compensation for the absence of dedicated chemosensory pathways. Basal lineages retain simplified CSS (F1 or F5), whereas Actinomycetes show lineage-specific expansion into multiple classes (F5, F8, F9, and ACF), often co-occurring, indicative of enhanced sensory complexity. The phylogeny of CheA homologs shows a polyphyletic distribution, supporting a mosaic evolutionary history shaped by multiple independent acquisitions, diversification, and gene loss. Collectively, our findings show that, unlike motile bacteria, members of Actinomycetota rely predominantly on TCS-driven regulatory networks, with CSS retained only in select lineages where ecological demands require enhanced environmental sensing. This work provides a phylum-wide evolutionary framework for the emergence, diversification, and functional specialization of CSS in non-motile bacteria.",
  "abstract_shown": true,
  "affiliations": [
    "Indian Institute of Technology Hyderabad"
  ],
  "article_type": "New results",
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "name": "S. N. S"
    },
    {
      "name": "S. Brighty"
    },
    {
      "affs": [
        0
      ],
      "name": "G. Sharma"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5wq5f0z0cztxs.bib",
  "cited_by": 0,
  "doi": "10.64898/2026.11.03.764138",
  "fulltext_url": "https://www.biorxiv.org/content/10.64898/2026.11.03.764138v1.full",
  "id": "5wq5f0z0cztxs",
  "issns": [],
  "landing_url": "https://www.biorxiv.org/content/10.64898/2026.11.03.764138v1",
  "language": null,
  "licence": "CC-BY-NC-ND",
  "licence_label": "CC BY-NC-ND",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "biorxiv",
      "microbiology"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://www.biorxiv.org/content/10.64898/2026.11.03.764138v1.full.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-03",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5wq5f0z0cztxs.ris",
  "sources": [
    {
      "first_seen": "2026-11-09T12:21:11Z",
      "native_id": "10.64898/2026.11.03.764138",
      "source": "biorxiv",
      "url": "https://www.biorxiv.org/content/10.64898/2026.11.03.764138v1"
    }
  ],
  "subjects": [
    {
      "field": "biology",
      "origin": "biorxiv:microbiology",
      "subfield": "microbiology"
    }
  ],
  "title": "Polyphyletic origins and lineage-specific expansion of chemosensory systems in phylum Actinomycetota",
  "title_text": "Polyphyletic origins and lineage-specific expansion of chemosensory systems in phylum Actinomycetota",
  "type": "preprint",
  "updated_at": "2026-11-09T12:21:11Z",
  "url": "https://research.draconitic.com/paper/5wq5f0z0cztxs",
  "venue": "bioRxiv",
  "versions": []
}