AUTHOR=Tendolkar Amruta , Pomerantz Aaron F. , Heryanto Christa , Shirk Paul D. , Patel Nipam H. , Martin Arnaud
TITLE=Ultrabithorax Is a Micromanager of Hindwing Identity in Butterflies and Moths
JOURNAL=Frontiers in Ecology and Evolution
VOLUME=9
YEAR=2021
URL=https://www.frontiersin.org/journals/ecology-and-evolution/articles/10.3389/fevo.2021.643661
DOI=10.3389/fevo.2021.643661
ISSN=2296-701X
ABSTRACT=
The forewings and hindwings of butterflies and moths (Lepidoptera) are differentiated from each other, with segment-specific morphologies and color patterns that mediate a wide range of functions in flight, signaling, and protection. The Hox gene Ultrabithorax (Ubx) is a master selector gene that differentiates metathoracic from mesothoracic identities across winged insects, and previous work has shown this role extends to at least some of the color patterns from the butterfly hindwing. Here we used CRISPR targeted mutagenesis to generate Ubx loss-of-function somatic mutations in two nymphalid butterflies (Junonia coenia, Vanessa cardui) and a pyralid moth (Plodia interpunctella). The resulting mosaic clones yielded hindwing-to-forewing transformations, showing Ubx is necessary for specifying many aspects of hindwing-specific identities, including scale morphologies, color patterns, and wing venation and structure. These homeotic phenotypes showed cell-autonomous, sharp transitions between mutant and non-mutant scales, except for clones that encroached into the border ocelli (eyespots) and resulted in composite and non-autonomous effects on eyespot ring determination. In the pyralid moth, homeotic clones converted the folding and depigmented hindwing into rigid and pigmented composites, affected the wing-coupling frenulum, and induced ectopic scent-scales in male androconia. These data confirm Ubx is a master selector of lepidopteran hindwing identity and suggest it acts on many gene regulatory networks involved in wing development and patterning.