GEPHE SUMMARY Print
Gephebase Gene
Entry Status
Published
GepheID
GP00000250
Main curator
Courtier
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
Drosophila auraria - Japan ; dark
Trait State in Taxon B
Drosophila auraria - Japan ; light
Ancestral State
Taxon A
Taxonomic Status
Taxon A
Common Name
-
Synonyms
-
Rank
species
Lineage
Show more ... era; Brachycera; Muscomorpha; Eremoneura; Cyclorrhapha; Schizophora; Acalyptratae; Ephydroidea; Drosophilidae; Drosophilinae; Drosophilini; Drosophila; Sophophora; melanogaster group; montium subgroup
NCBI Taxonomy ID
is Taxon A an Infraspecies?
Yes
Taxon A Description
Drosophila auraria - Japan ; dark
Taxon B
Common Name
-
Synonyms
-
Rank
species
Lineage
Show more ... era; Brachycera; Muscomorpha; Eremoneura; Cyclorrhapha; Schizophora; Acalyptratae; Ephydroidea; Drosophilidae; Drosophilinae; Drosophilini; Drosophila; Sophophora; melanogaster group; montium subgroup
NCBI Taxonomy ID
is Taxon B an Infraspecies?
Yes
Taxon B Description
Drosophila auraria - Japan ; light
GENOTYPIC CHANGE
Presumptive Null
No
Molecular Type
Aberration Type
Molecular Details of the Mutation
Inactivation of a conserved silencer resulting in gain-of-expression; the increase in ebony expression in the light strain occurred primarily through mutations affecting the ebony male-specific silencer element
Experimental Evidence
Authors
Johnson WC; Ordway AJ; Watada M; Pruitt JN; Williams TM; Rebeiz M
Abstract
The modification of transcriptional regulation has become increasingly appreciated as a major contributor to morphological evolution. However, the role of negative-acting control elements (e.g. silencers) in generating morphological diversity has been generally overlooked relative to positive-acting "enhancer" elements. The highly variable body coloration patterns among Drosophilid insects represents a powerful model system in which the molecular alterations that underlie phenotypic diversity can be defined. In a survey of pigment phenotypes among geographically disparate Japanese populations of Drosophila auraria, we discovered a remarkable degree of variation in male-specific abdominal coloration. In testing the expression patterns of the major pigment-producing enzymes, we found that phenotypes uniquely correlated with differences in the expression of ebony, a gene required for yellow-colored cuticle. Assays of ebony's transcriptional control region indicated that a lightly pigmented strain harbored cis-regulatory mutations that caused correlated changes in its expression. Through a series of chimeric reporter constructs between light and dark strain alleles, we localized function-altering mutations to a conserved silencer that mediates a male-specific pattern of ebony repression. This suggests that the light allele was derived through the loss of this silencer's activity. Furthermore, examination of the ebony gene of D. serrata, a close relative of D. auraria which secondarily lost male-specific pigmentation revealed the parallel loss of this silencer element. These results demonstrate how loss-of-function mutations in a silencer element resulted in increased gene expression. We propose that the mutational inactivation of silencer elements may represent a favored path to evolve gene expression, impacting morphological traits.
Additional References
RELATED GEPHE
Related Genes
Related Haplotypes
No matches found.
COMMENTS
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