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Butterfly wing pattern mutants: developmental heterochrony and co-ordinately regulated phenotypes.
P B Koch1, U Lorenz, P M Brakefield
1Department of General Zoology and Endocrinology, University of Ulm, Albert-Einstein-Allee 11, 89081 Ulm, Germany. bernd.koch@biologie.uni-ulm.de
Development Genes and Evolution
|February 17, 2001
Summary
Butterfly wing color patterns are formed by pigment deposition and melanization in scales. Developmental timing changes, or heterochrony, in scale development can alter these patterns, creating new colors or positions.
Area of Science:
- Developmental biology
- Genetics
- Evolutionary biology
Background:
- Butterfly wing coloration involves pigment synthesis and melanization in specialized scales during late development.
- A fixed developmental succession dictates pigment deposition and melanization, influencing the final wing pattern.
Purpose of the Study:
- Investigate developmental changes in two butterfly wing pattern mutants: a melanic swallowtail (Papilio glaucus) and a spotty satyrid (Bicyclus anynana).
- Determine how altered rates of scale development influence final color patterns and element positioning.
Main Methods:
- Comparative analysis of scale development timing in wild-type and mutant butterflies.
- Observation of pigment synthesis (papiliochrome) and melanization processes.
- Examination of scale maturation sequences in different pattern elements like background and eyespots.
Main Results:
- In P. glaucus, delayed scale development led to failure in yellow pigment (papiliochrome) synthesis, resulting in melanization.
- In B. anynana, additional eyespots resulted from accelerated scale development in non-eyespot areas.
- Changes in the rate of scale development directly correlate with alterations in color and position of wing pattern elements.
Conclusions:
- Heterochrony, or shifts in developmental timing of scale development, is a fundamental mechanism for butterfly color pattern formation.
- Developmental mutants can alter wing patterns by modifying the heterochrony of scale development.
- This mechanism provides a basis for understanding the evolution of diverse lepidopteran wing patterns.