Related Experiment Video

Updated: Jul 26, 2026

Determination of the Optimal Chromosomal Location(s) for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach
11:12

Determination of the Optimal Chromosomal Location(s) for a DNA Element in Escherichia coli Using a Novel Transposon-mediated Approach

Published on: September 11, 2017

Dynamics of R1 and R2 elements in the rDNA locus of Drosophila simulans

C E Pérez-González1, T H Eickbush

  • 1Department of Biology, University of Rochester, Rochester, New York 14627, USA.

Genetics
|August 22, 2001
PubMed
Summary

Mobile elements R1 and R2 rapidly turn over in arthropod rDNA loci due to strong recombinational bias. This suggests a higher retrotransposition frequency than previously thought, impacting gene locus evolution.

More Related Videos

Single Nucleotide Polymorphism-sensitive FISH Detection of Locus-specific Ribosomal RNA Transcription in Drosophila melanogaster04:59

Single Nucleotide Polymorphism-sensitive FISH Detection of Locus-specific Ribosomal RNA Transcription in Drosophila melanogaster

Published on: March 28, 2025

RNA-Associated Chromatin DNA-DNA Interaction Method11:01

RNA-Associated Chromatin DNA-DNA Interaction Method

Published on: April 30, 2026

Related Concept Videos

Position-effect Variegation02:32

Position-effect Variegation

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.
Polytene Chromosomes02:04

Polytene Chromosomes

Polytene chromosomes are giant interphase chromosomes with several DNA strands placed side by side. They were discovered in the year 1881 by Balbiani in salivary glands, intestine, muscles, malpighian tubules, and hypoderm of larvae Chironomus plumosus. Hence, these are also called "Salivary gland chromosomes." These are found in insects of the order Diptera and Collembola; in certain organs of mammals; and synergids, antipodes of flowering plants. Polytene chromosomes are also regularly...
Cis-regulatory Sequences02:02

Cis-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...
The Ratio of X Chromosome to Autosomes02:45

The Ratio of X Chromosome to Autosomes

In most organisms, sex is determined by the ratio of X and Y chromosomes. However, in some organisms, such as Drosophila and C.elegans, sex is determined by the ratio of the number of X chromosomes to the number of sets of autosomes. The Y chromosome in Drosophila is active but does not determine sex. It contains genes responsible for the production of sperms in adult flies.  
Normal male Drosophila has a ratio of one X chromosome to two sets of autosomes. In contrast, normal female Drosophila...
Exon Recombination02:32

Exon Recombination

The evolution of new genes is critical for speciation. Exon recombination, also known as exon shuffling or domain shuffling, is an important means of new gene formation. It is observed across vertebrates, invertebrates, and in some plants such as potatoes and sunflowers. During exon recombination, exons from the same or different genes recombine and produce new exon-intron combinations, which might evolve into new genes. 
Exon shuffling follows “splice frame rules.” Each exon has three reading...