A long noncoding RNA at the cortex locus controls adaptive coloration in butterflies

• 成果类型: Article
• 署名作者: Livraghi, Luca; Hanly, Joseph J.; Evans, Elizabeth; Wright, Charlotte J.; Loh, Ling S.; Mazo-Vargas, Anyi; Kamrava, Kiana; Carter, Alexander; van der Heijden, Eva S. M.; Reed, Robert D.; Papa, Riccardo; Jiggins, Chris D.; Martin, Arnaud
• 署名单位: George Washington University; University of Cambridge; Duke University; Smithsonian Institution; Smithsonian Tropical Research Institute; University of Puerto Rico; University of Puerto Rico Rio Piedras; Wellcome Trust Sanger Institute; Cornell University; University of Puerto Rico; University of Puerto Rico Medical Sciences Campus; University of Puerto Rico; University of Parma
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-9071
• DOI: 10.1073/pnas.2403326121
• 发表日期: 2024-09-03
• 关键词: mimicry; gene; architecture; EVOLUTION; sequence; meiosis; reveals

摘要

Evolutionary variation in the wing pigmentation of butterflies and moths offers striking examples of adaptation by crypsis and mimicry. The cortex locus has been independently mapped as the locus controlling color polymorphisms in 15 lepidopteran species, suggesting that it acts as a genomic hotspot for the diversification of wing patterns, but functional validation through protein- coding knockouts has proven difficult to obtain. Our study unveils the role of a long noncoding RNA (lncRNA) which we name ivory, transcribed from the cortex locus, in modulating color patterning in butterflies. Strikingly, ivory expression prefigures most melanic patterns during pupal development, suggesting an early developmental role in specifying scale identity. To test this, we generated CRISPR mosaic knock- outs in five nymphalid butterfly species and show that ivory mutagenesis yields transformations of dark pigmented scales into white or light- colored scales. Genotyping of Vanessa cardui germline mutants associates these phenotypes to small on- target deletions at the conserved first exon of ivory. In contrast, cortex germline mutant butterflies with confirmed null alleles lack any wing phenotype and exclude a color patterning role for this adjacent gene. Overall, these results show that a lncRNA gene acts as a master switch of color pattern specification and played key roles in the adaptive diversification of wing patterns in butterflies.