Related Experiment Video

Updated: Jun 18, 2026

Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells
14:26

Genome-wide Purification of Extrachromosomal Circular DNA from Eukaryotic Cells

Published on: April 4, 2016

Ubiquitous internal gene duplication and intron creation in eukaryotes.

Xiang Gao1, Michael Lynch

  • 1Department of Biology, Indiana University, 1001 East Third Street, Bloomington, IN 47405, USA. gao3@indiana.edu

Proceedings of the National Academy of Sciences of the United States of America
|November 21, 2009
PubMed
Summary

Internal gene segment duplications are frequent evolutionary events, contributing to genomic novelty and intron gain. This study highlights their significant role in shaping genomes.

More Related Videos

Assessment of DNA Contamination in RNA Samples Based on Ribosomal DNA13:16

Assessment of DNA Contamination in RNA Samples Based on Ribosomal DNA

Published on: January 22, 2018

Related Concept Videos

Gene Duplication and Divergence02:37

Gene 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.
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...
Genome Size and the Evolution of New Genes03:21

Genome Size and the Evolution of New Genes

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.
Genome Size and the Evolution of New Genes03:21

Genome Size and the Evolution of New Genes

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.
Organization of Genes02:07

Organization of Genes

Overview
Gene Families01:57

Gene Families

Gene families consist of groups of genes proposed to have originated from a common ancestor. Typically these arise through events in which a gene or genes are mistakenly duplicated during cell division. Unlike their parent genes (which are subject to selection pressure to maintain function), these gene copies do not need to preserve their sequences and may evolve at a relatively faster rate.
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...