Distal-less regulates eyespot patterns and melanization in Bicyclus butterflies.

Butterfly eyespots represent novel complex traits that display substantial diversity in number and size within and across species. Correlative gene expression studies have implicated a large suite of transcription factors, including Distal-less (Dll), Engrailed (En), and Spalt (Sal), in eyespot development in butterflies, but direct evidence testing the function of any of these proteins is still missing. Here we show that the characteristic two-eyespot pattern of wildtype Bicyclus anynana forewings is correlated with dynamic progression of Dll, En, and Sal expression in larval wings from four spots to two spots, whereas no such decline in gene expression ensues in a four-eyespot mutant.

Transgenic approaches to study wing color pattern development in Lepidoptera.

The extremely diverse lepidopteran wing patterns make useful models to study the evolution of development and the molecular changes that enable it. Until now, the implication of candidate genes in the differentiation of color patterns has relied primarily on correlational evidence, i.e.

Temporal and spatial control of transgene expression using laser induction of the hsp70 promoter.

Background: Precise temporal and spatial regulation of transgene expression is a critical tool to investigate gene function in developing organisms. The most commonly used technique to achieve tight control of transgene expression, however, requires the use of specific DNA enhancers that are difficult to characterize in non-model organisms. Here, we sought to eliminate the need for this type of sequence-based gene regulation and to open the field of functional genetics to a broader range of organisms.

Germline transformation of the butterfly Bicyclus anynana.

Ecological and evolutionary theory has frequently been inspired by the diversity of colour patterns on the wings of butterflies. More recently, these varied patterns have also become model systems for studying the evolution of developmental mechanisms. A technique that will facilitate our understanding of butterfly colour-pattern development is germline transformation.