Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

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.
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...
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.
Genome Copying Errors02:46

Genome Copying Errors

DNA replication is a well-evolved process that copies millions of base pairs with high fidelity during each cell division. Occasionally a wrong base or a long stretch of wrong bases may get added to the daughter strands. If the errors are left unchecked, cells might accumulate several mutations that might endanger their  survival. Therefore, the copying errors are checked and repaired at three levels.
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...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Transposable element insertions have strongly affected human evolution.

Proceedings of the National Academy of Sciences of the United States of America·2010
Same author

The majority of human genes have regions repeated in other human genes.

Proceedings of the National Academy of Sciences of the United States of America·2005
Same author

Coding sequences of functioning human genes derived entirely from mobile element sequences.

Proceedings of the National Academy of Sciences of the United States of America·2004
Same author

Majority of divergence between closely related DNA samples is due to indels.

Proceedings of the National Academy of Sciences of the United States of America·2003
Same author

Divergence between samples of chimpanzee and human DNA sequences is 5%, counting indels.

Proceedings of the National Academy of Sciences of the United States of America·2002

Related Experiment Video

Updated: Jul 18, 2026

G2-seq: A High Throughput Sequencing-based Technique for Identifying Late Replicating Regions of the Genome
06:40

G2-seq: A High Throughput Sequencing-based Technique for Identifying Late Replicating Regions of the Genome

Published on: March 22, 2018

Almost all human genes resulted from ancient duplication.

Roy J Britten1

  • 1California Institute of Technology, 101 Dahlia Avenue, Corona del Mar, CA 92625, USA. r.britten@comcast.net

Proceedings of the National Academy of Sciences of the United States of America
|December 6, 2006
PubMed
Summary

Gene duplication is a key evolutionary process. This study reveals extensive, previously unreported protein relationships in human genes, suggesting ancient duplication events shaped the genome.

More Related Videos

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

Following the Dynamics of Structural Variants in Experimentally Evolved Populations
04:52

Following the Dynamics of Structural Variants in Experimentally Evolved Populations

Published on: February 3, 2023

Related Experiment Videos

Last Updated: Jul 18, 2026

G2-seq: A High Throughput Sequencing-based Technique for Identifying Late Replicating Regions of the Genome
06:40

G2-seq: A High Throughput Sequencing-based Technique for Identifying Late Replicating Regions of the Genome

Published on: March 22, 2018

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

Following the Dynamics of Structural Variants in Experimentally Evolved Populations
04:52

Following the Dynamics of Structural Variants in Experimentally Evolved Populations

Published on: February 3, 2023

Area of Science:

  • Genomics
  • Evolutionary Biology
  • Bioinformatics

Background:

  • Gene duplication is a fundamental mechanism driving genome evolution.
  • Understanding the history of gene duplications provides insights into genomic complexity.

Purpose of the Study:

  • To identify and quantify previously unreported protein relationships within the human genome.
  • To investigate the extent of ancient gene duplication events as revealed by protein sequence similarity.

Main Methods:

  • Utilized BLASTp with an open criterion (expectation value ≤ 2) for protein sequence comparison.
  • Analyzed a curated library of 13,298 human genes (Known Genes Maximum Variant - KGMV), including only the longest transcript variant for each gene.
  • Validated the significance of observed matches using random protein sequence comparisons.

Main Results:

  • >97% of human genes exhibit significant sequence similarity to each other when all match lengths are considered.
  • A substantial number of proteins share matches with numerous other proteins, indicating a mosaic structure derived from ancient duplications.
  • Random sequence comparisons confirmed that the observed matches in the KGMV set are highly significant and not due to chance.

Conclusions:

  • The human genome shows a vast network of ancient protein relationships, largely underestimated until now.
  • Protein sequence analysis strongly supports gene duplication as a major force in shaping the human genome.
  • The findings highlight the pervasive impact of ancient duplication events on the structure and evolution of human genes.