Related Experiment Video
Updated: Jun 24, 2026
08:52
Hairy Root Transformation and Regeneration in Arabidopsis thaliana and Brassica napus
Published on: December 22, 2023
Evolution of MIR168 paralogs in Brassicaceae
Silvia Gazzani1, Mingai Li, Silvia Maistri
1Environment and Natural Resources Area, Fondazione Edmund Mach, via Mach 1, 38010 San Michele all'Adige (TN), Italy. silvia.gazzani@iasma.it
BMC Evolutionary Biology
|March 25, 2009
Summary
The evolution of MIR168 paralogs in Brassicaceae shows high conservation of functionally relevant regions, indicating sustained function. MIR168b has undergone partial subfunctionalization, and its pre-miRNA lower stem is longer than in animals, suggesting a role in biogenesis.
Area of Science:
- Plant molecular biology
- Evolutionary genomics
- RNA silencing pathways
Background:
- ARGONAUTE1 (AGO1) expression is regulated by a feedback loop involving miR168.
- This auto-regulatory loop maintains AGO1 homeostasis, crucial for miRNA pathway function.
Purpose of the Study:
- To investigate the genomic organization, structural, and functional evolution of MIR168 homologs in Brassicaceae.
- To determine the evolutionary history and conservation of MIR168 paralogs.
Main Methods:
- Comparative genomics and phylogenetic footprinting.
- Phylogenetic reconstruction to date duplication events.
- Analysis of conserved regions and secondary structures of MIR168 homologs.
Main Results:
- MIR168 paralogs originated before Brassicaceae radiation and Arabidopsis polyploidization.
- Orthologs of Arabidopsis MIR168a and MIR168b were found in all analyzed Brassicaceae species.
- Highly conserved functionally relevant regions and secondary structures were identified in MIR168 homologs.
Conclusions:
- MIR168 paralogs have been functionally maintained throughout Brassicaceae evolution.
- MIR168b shows evidence of partial subfunctionalization in Arabidopsis.
- The pre-miR168 lower stem's length suggests a significant role in multi-step biogenesis.
Related Concept Videos
02:02Cis-regulatory Sequences
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...
01:24Evolution of New Traits in Microbes
Microorganisms evolve rapidly due to their large population sizes and short generation times, often exhibiting measurable changes within days under laboratory conditions. Natural selection acts on standing genetic variation, enabling the retention and amplification of beneficial traits that confer fitness advantages in changing environments.Adaptive Pigment Regulation in RhodobacterIn Rhodobacter, a genus of purple non-sulfur bacteria, light-harvesting pigments such as bacteriochlorophyll and...
01:08Evolution of Microbial Genome
Microbial genome evolution is a highly dynamic process shaped by continual gene gain and loss across species and strains. This genomic flexibility allows microorganisms to adapt rapidly to environmental pressures and interactions with other organisms. Central to understanding this diversity is the distinction between the core and pan genomes.The core genome comprises the genes shared by all sampled strains of a species, representing essential functions needed for fundamental cellular processes.
02:37Gene Duplication and Divergence
The seminal work of Ohno in 1970 popularized the idea of gene duplication and divergence. DNA sequence comparison studies reveal that a large portion of the genes in bacteria, archaebacteria, and eukaryotes was generated by gene duplication and divergence, indicating its critical role in evolution.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
The duplicated copies of the gene are called Paralogs. Paralogs with similar sequences and functions form a gene family. Across several species, a large number of gene families are characterized.
02:26Conservation of Protein Domains Over Different Proteins
Protein domains are small structurally independent units that are part of a single amino acid chain. Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to form...
01:25Cell Signaling in Plants
Plant cells communicate to coordinate their cycle of growth, flowering and fruiting, and activities in roots, shoots, and leaves in response to the changing environmental conditions. Plant signaling is distinct from animal signaling. Plants primarily utilize enzyme-linked receptors, whereas the largest class of cell-surface receptors in animals are G-protein coupled receptors (GPCRs). Unlike animals, receptor tyrosine kinases are rare in plants. Instead, plants have a diverse class of...