The gene ivory:mir-193 controls scale type differentiation in Heliconius butterflies
Abstract The ivory:mir-193 locus is a genetic hotspot underlying melanic wing pattern variation across Lepidoptera, acting as a master regulator of melanic scale fate. This includes the genus Heliconius , where aposematic mimicry is driven by three scale cell types: light Type I, dark-melanic Type II, and red Type III scales. We tested functions of ivory:mir-193 in Heliconius using CRISPR-induced somatic mosaic knockouts of ivory and mir-193 across multiple pattern morphs. Knockouts converted Type II scales to Type I scales. Effects on Type III scales varied among and within individuals, indicating that ivory:mir-193 is permissive for Type III development. Using single-nucleus RNA-seq, we profiled the transcriptional landscape of H. melpomene -Δ78k mutants lacking mir-193 . Loss of mir-193 produced readthrough transcription, consistent with a model where miR-193 acts as a co-transcriptional terminator. These data show that ivory drives wing pattern variation, while mir-193 mediates downstream diversity in scale fate across Lepidoptera.
Authors
- Julia C. Holder (ORCID: https://orcid.org/0009-0002-5971-5599)
- Ling Sheng Loh (ORCID: https://orcid.org/0000-0003-0981-7984)
- Lawrence E. Gilbert (ORCID: https://orcid.org/0000-0003-4418-2996)
- Leia Zhao
- Arnaud Martin (ORCID: https://orcid.org/0000-0002-5980-2249)
- Luca Livraghi (ORCID: https://orcid.org/0000-0002-2597-7550)
- Joseph J. Hanly (ORCID: https://orcid.org/0000-0002-9459-9776)
- Gregory A. Wray (ORCID: https://orcid.org/0000-0001-5634-5081)
- W. Owen McMillan (ORCID: https://orcid.org/0000-0003-2805-2745)
- Carlos Federico Arias (ORCID: https://orcid.org/0000-0003-3130-4501)
- Pushkar Ravindra Wagh (ORCID: https://orcid.org/0009-0004-1147-5172)
- Leo T. Camino (ORCID: https://orcid.org/0009-0002-5153-8612)
- Paola Calderon-Oñate (ORCID: https://orcid.org/0009-0004-4168-3407)
- Joshue Ruiz (ORCID: https://orcid.org/0000-0002-6212-1380)
- Eva D. Stroh
Institutions
- Smithsonian Tropical Research Institute (PA)
- Duke University (US)
- George Washington University (US)
- The University of Texas at Austin (US)
Publication Details
- Journal
- Nature Communications
- Published
- 2026-11-01
- DOI
- https://doi.org/10.1038/s41467-026-79315-w
- Citations
- 1
- Primary Topic
- Lepidoptera: Biology and Taxonomy
- Type
- article
- Field-Weighted Citation Impact
- 3.90
Funders
- National Science Foundation
- Smithsonian Institution
- University of Texas at Austin