Related Experiment Video
Updated: Feb 18, 2026
08:03
Methods for Staging Pupal Periods and Measurement of Wing Pigmentation of Drosophila guttifera
Published on: January 24, 2018
12.4K
Evolution of flower color pattern through selection on regulatory small RNAs
Desmond Bradley1, Ping Xu2, Irina-Ioana Mohorianu2,3
1Department of Cell and Developmental Biology, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK.
Science (New York, N.Y.)
|November 18, 2017
Summary
Population-wide snapdragon color differences arise from inverted duplications producing small RNAs (sRNAs). These sRNAs regulate pigment genes, driving evolutionary diversity and demonstrating selection on recent sRNA evolution.
Area of Science:
- Evolutionary biology
- Genetics
- Molecular biology
Background:
- Small RNAs (sRNAs) are crucial gene regulators in both plants and animals.
- Phenotypic variation, such as flower color patterns, can arise from genetic changes.
Purpose of the Study:
- To investigate the genetic basis of population-wide color pattern differences in snapdragon flowers.
- To understand the role of small RNAs (sRNAs) in generating phenotypic diversity.
Main Methods:
- Analysis of inverted duplications and their generated transcripts.
- Characterization of small RNA (sRNA) production and function.
- Population genetics analysis in a natural hybrid zone.
Main Results:
- An inverted duplication was identified as the cause of sRNA generation leading to color variation.
- These sRNAs were shown to repress a pigment biosynthesis gene, creating a distinct yellow highlight.
- The duplication showed steep allele frequency clines, indicating it is under natural selection.
Conclusions:
- Evolutionarily recent sRNAs, originating from duplications, can be targets of natural selection.
- These sRNAs contribute significantly to the evolution of phenotypic diversity in natural populations.
- The findings suggest these duplications are intermediates in microRNA evolution.
Related Concept Videos
02:02Cis-regulatory Sequences
12.0K
Cis-regulatory sequences are short fragments of non-coding DNA that are present on the same chromosomes as the genes that they regulate. These fragments serve as binding sites for transcriptional regulators, proteins that are responsible for controlling gene transcription and differential gene expression across cell types in eukaryotes. Cis-regulatory sequences can be close to the gene of interest or thousands of bases away in the DNA sequence; however, those sequences that are further away are...
12.0K
01:21Frequency-dependent Selection
24.3K
When the fitness of a trait is influenced by how common it is (i.e., its frequency) relative to different traits within a population, this is referred to as frequency-dependent selection. Frequency-dependent selection may occur between species or within a single species. This type of selection can either be positive—with more common phenotypes having higher fitness—or negative, with rarer phenotypes conferring increased fitness.
24.3K
01:29Translational Regulation
691
Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
691
02:32Position-effect Variegation
7.2K
In 1928, a German botanist Emil Heitz observed the moss nuclei with a DNA binding dye. He observed that while some chromatin regions decondense and spread out in the interphase nucleus, others do not. He termed them euchromatin and heterochromatin, respectively. He proposed that the heterochromatin regions reflect a functionally inactive state of the genome. It was later confirmed that heterochromatin is transcriptionally repressed, and euchromatin is transcriptionally active chromatin.
7.2K
01:23Regulation of Expression at Multiple Steps
1.4K
The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the...
1.4K
02:24Regulation of Expression Occurs at Multiple Steps
26.6K
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
26.6K