Genome editing in butterflies reveals that spalt promotes and Distal-less represses eyespot colour patterns.
Butterfly eyespot colour patterns are a key example of how a novel trait can appear in association with the co-option of developmental patterning genes. Little is known, however, about how, or even whether, co-opted genes function in eyespot development. Here we use CRISPR/Cas9 genome editing to determine the roles of two co-opted transcription factors that are expressed during early eyespot determination. We found that deletions in a single gene, spalt, are sufficient to reduce or completely delete eyespot colour patterns, thus demonstrating a positive regulatory role for this gene in eyespot determination. Conversely, and contrary to previous predictions, deletions in Distal-less (Dll) result in an increase in the size and number of eyespots, illustrating a repressive role for this gene in eyespot development. Altogether our results show that the presence, absence and shape of butterfly eyespots can be controlled by the activity of two co-opted transcription factors.
Department of Ecology and Evolutionary Biology, Cornell University, 215 Tower Road, Ithaca, New York 14853-7202, USA.
Linlin
L
Zhang
Department of Ecology and Evolutionary Biology, Cornell University, 215 Tower Road, Ithaca, New York 14853-7202, USA.
Robert D
RD
Reed
D000818:Animals; D001483:Base Sequence; D002080:Butterflies / Q000235:genetics*; D064113:CRISPR-Cas Systems / Q000235:genetics; D003116:Color; D005123:Eye / Q000378:metabolism*; D017353:Gene Deletion; D000072669:Gene Editing; D017344:Genes, Insect; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D010858:Pigmentation / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D014921:Wings, Animal / Q000378:metabolism
D018398:Homeodomain Proteins; D012097:Repressor Proteins