Related Experiment Video
Updated: Jan 22, 2026
12:02
Molecular Evolution of the Tre Recombinase
Published on: May 29, 2008
10.1K
Changes throughout a Genetic Network Mask the Contribution of Hox Gene Evolution
Yang Liu1, Margarita Ramos-Womack2, Clair Han3
1Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 15260, USA.
Current Biology : CB
|July 2, 2019
Summary
Evolutionary changes in Hox gene expression can alter animal body plans. However, complex gene interactions, like epistasis, can mask the direct effects of these genes on traits such as pigmentation.
Area of Science:
- Developmental Biology
- Evolutionary Biology
- Genetics
Background:
- Hox genes are crucial for establishing the anterior-posterior axis in animals.
- Their role in the evolution of animal body plans is significant but challenging to pinpoint.
- Previous research linked Hox gene Abd-B to pigmentation in Drosophila yakuba.
Purpose of the Study:
- To investigate evolutionary modifications in the Hox gene Abd-B.
- To understand the genetic basis for the loss of body pigmentation in Drosophila santomea.
- To explore how gene networks and epistasis contribute to macroevolutionary changes.
Main Methods:
- Identified evolutionary modifications in the Hox gene Abd-B expression in Drosophila santomea.
- Manipulated Abd-B gene expression in current-day Drosophila santomea.
- Analyzed the pigmentation network involving Abd-B and other interacting genes.
Main Results:
- Significant alterations in Abd-B expression were found along the body plan of Drosophila santomea.
- Direct manipulation of Abd-B did not affect pigmentation in Drosophila santomea, contrary to predictions.
- Epistasis involving four other genes, three with altered expression patterns, explained the lack of Abd-B effect on pigmentation.
Conclusions:
- Body plan evolution can occur through incremental changes across Hox-regulated gene networks.
- Polygenicity and epistasis can obscure the direct contribution of individual genes to major evolutionary traits.
- Understanding complex genetic interactions is key to deciphering macroevolutionary mechanisms.
Related Concept Videos
03:21Genome Size and the Evolution of New Genes
9.0K
While every living organism has a genome of some kind (be it RNA, or DNA), there is considerable variation in the sizes of these blueprints. One major factor that impacts genome size is whether the organism is prokaryotic or eukaryotic. In prokaryotes, the genome contains little to no non-coding sequence, such that genes are tightly clustered in groups or operons sequentially along the chromosome. Conversely, the genes in eukaryotes are punctuated by long stretches of non-coding sequence.
9.0K
03:21Genome Size and the Evolution of New Genes
3.3K
3.3K
02:05Gene Evolution - Fast or Slow?
8.0K
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
8.0K
02:05Gene Evolution - Fast or Slow?
3.4K
3.4K
01:09Mutation, Gene Flow, and Genetic Drift
63.1K
In a population that is not at Hardy-Weinberg equilibrium, the frequency of alleles changes over time. Therefore, any deviations from the five conditions of Hardy-Weinberg equilibrium can alter the genetic variation of a given population. Conditions that change the genetic variability of a population include mutations, natural selection, non-random mating, gene flow, and genetic drift (small population size).
63.1K
02:55The Evidence for Evolution
47.7K
Genetic variations accumulating within populations over generations give rise to biological evolution. Evolutionary changes can result in the formation of novel varieties and entire new species. These changes are responsible for the diverse forms of life inhabiting the planet. The evidence for evolution suggests that all living organisms descended from common ancestors.
47.7K