Related Experiment Video
Updated: Jul 11, 2025
09:57
2D and 3D Chromosome Painting in Malaria Mosquitoes
Published on: January 6, 2014
10.3K
Patterns of chromosome evolution in ruminants.
Cristina Arias-Sardá1, Sarah Quigley1, Marta Farré1
1School of Biosciences, University of Kent, Canterbury, UK.
Molecular Ecology
|November 8, 2023
Summary
Gross genomic rearrangements in ruminants reveal evolutionary patterns. Evolutionary breakpoint regions (EBRs) are gene-poor, offering new insights into genome evolution and speciation.
Area of Science:
- Genomics
- Evolutionary Biology
- Comparative Genomics
Background:
- Understanding genome structure changes is crucial for deciphering evolutionary processes and speciation.
- Ruminants exhibit significant karyotype diversity, making them an ideal model for studying chromosomal evolution.
Purpose of the Study:
- To identify and characterize gross chromosomal rearrangements in ruminant evolution.
- To pinpoint evolutionary breakpoint regions (EBRs) and understand their genomic features.
Main Methods:
- Reconstruction of five ancestral ruminant karyotypes using 26 genome assemblies.
- Classification of chromosomal rearrangement events (inversions, interchromosomal rearrangements) across ruminant lineages.
- Identification and analysis of evolutionary breakpoint regions (EBRs) and synteny fragments.
Main Results:
- Ruminant karyotype evolution is dominated by inversions, with early interchromosomal rearrangements in the oldest ancestor.
- Evolutionary breakpoint regions (EBRs) were identified and found to be depleted of protein-coding and housekeeping genes.
- EBRs are not enriched in high GC regions, suggesting alternative mechanisms for their formation beyond meiotic double-strand breaks.
Conclusions:
- This study provides a detailed map of chromosome rearrangements in ruminant evolution.
- Findings offer novel insights into the characteristics and potential origins of evolutionary breakpoint regions (EBRs).
- Understanding these genomic events contributes to the broader knowledge of genome evolution and the genetic basis of speciation.
Related Concept Videos
02:31Synteny and Evolution
3.3K
John H. Renwick first coined the term “synteny” in 1971, which refers to the genes present on the same chromosomes, even if they are not genetically linked. The species with common ancestry tend to show conserved syntenic regions. Therefore, the concept of synteny is nowadays used to describe the evolutionary relationship between species.
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral...
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral...
3.3K
02:05Gene Evolution - Fast or Slow?
7.1K
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...
7.1K
02:54Evolutionary Relationships through Genome Comparisons
5.8K
Genome comparison is one of the excellent ways to interpret the evolutionary relationships between organisms. The basic principle of genome comparison is that if two species share a common feature, it is likely encoded by the DNA sequence conserved between both species. The advent of genome sequencing technologies in the late 20th century enabled scientists to understand the concept of conservation of domains between species and helped them to deduce evolutionary relationships across diverse...
5.8K
02:13Overview of Transposition and Recombination
15.6K
Transposons make up a significant part of genomes of various organisms. Therefore, it is believed that transposition played a major evolutionary role in speciation by changing genome sizes and modifying gene expression patterns. For example, in bacteria, transposition can lead to conferring antibiotic resistance. Movement of transposable elements within the genetic pool of pathogenic bacteria can aid in transfer of antibiotic-resistant genetic elements. In eukaryotes, transposons can carry out...
15.6K
02:37Gene Duplication and Divergence
6.1K
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...
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...
6.1K
01:51Lampbrush Chromosomes
7.9K
In 1882, Flemming observed lampbrush chromosomes (LBC) in salamander eggs. Later in 1892, Rückert observed LBCs in shark egg cells and coined the term "lampbrush chromosomes" because they looked like brushes used to clean kerosene lamps.
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops...
LBCs are made up of two pairs of conjugating homologous chromatids. Each chromatid consists of alternatively positioned regions of condensed-inactive chromatin and loosely placed-active side loops, which can be contracted and extended. The loops...
7.9K