Two or Four Bristles: Functional Evolution of an Enhancer of scute in Drosophilidae
2006
Study of Enhancer Supports Evolution Model
publication
Evidence: high
Author Information
Author(s): Sylvain Marcellini, Pat Simpson
Hypothesis
The appearance of two versus four thoracic bristles in fruit flies is due to small sequence changes in the regulatory region of a single gene.
Conclusion
The study shows that slight changes in enhancers can lead to changes in gene expression and phenotype, supporting a common model of morphologic evolution.
Supporting Evidence
- The study shows that D. quadrilineata has four bristles while D. melanogaster has two due to differences in the scute gene's regulatory sequences.
- By inserting the D. quadrilineata enhancer into D. melanogaster, the flies developed four bristles instead of two.
- The findings support the idea that small genetic changes can lead to significant morphological differences over time.
Takeaway
This study found that tiny changes in DNA can change how many bristles a fruit fly has, helping us understand how new species can form over time.
Methodology
The authors compared the sequences of the dorsocentral enhancers of two fruit fly species and conducted experiments to observe scute expression.
Digital Object Identifier (DOI)
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