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

Karyotyping01:17

Karyotyping

49.3K
Overview
49.3K
Nondisjunction01:29

Nondisjunction

68.0K
During meiosis, chromosomes occasionally separate improperly. This occurs due to failure of homologous chromosome separation during meiosis I or failed sister chromatid separation during meiosis II. In some species, notably plants, nondisjunction can result in an organism with an entire additional set of chromosomes, which is called polyploidy. In humans, nondisjunction can occur during male or female gametogenesis and the resulting gametes possess one too many or one too few chromosomes.
68.0K
The Ratio of X Chromosome to Autosomes02:45

The Ratio of X Chromosome to Autosomes

11.5K
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...
11.5K
Evolutionary Relationships through Genome Comparisons02:54

Evolutionary 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
Synteny and Evolution02:31

Synteny and Evolution

2.9K
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...
2.9K
Nondisjunction01:21

Nondisjunction

4.5K
Nondisjunction is the failure of homologous chromosomes or sister chromatids to separate correctly and move to the opposite poles of the cells. This produces daughter cells with abnormal chromosome numbers.  Nondisjunction is common during anaphase I or anaphase II of meiosis.  Mutations in synaptonemal complex proteins that attach homologous chromosomes increase the chances of nondisjunction in anaphase I of meiosis I. In contrast, mutations in topoisomerases and condensins that hold...
4.5K

You might also read

Related Articles

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

Sort by
Same author

ERGA-BGE reference genome of the Eurasian Woodcock ( <i>Scolopax rusticola</i>), a game bird species with isolated populations of conservation interest.

Open research Europe·2026
Same author

The complete genome of 'Candidatus Phytoplasma phoenicium' highlights carboxylic acids as primary carbon and energy substrates in phytoplasmas.

Scientific reports·2026
Same author

ERGA-BGE reference genome of <i>Gambusia holbrooki</i>, a globally invasive freshwater fish.

Open research Europe·2026
Same author

Diversity Analysis of the Sugar Beet Pathogens '<i>Candidatus</i> Arsenophonus phytopathogenicus' and '<i>Ca</i>. Phytoplasma solani'.

Plants (Basel, Switzerland)·2026
Same author

An automated decision-making procedure for ranking and selecting species in biodiversity projects.

npj biodiversity·2026
Same author

ERGA-BGE reference genome of <i>Xylophaga dorsalis -</i> a common deep-sea wood-boring bivalve with Atlantic-Mediterranean distribution.

Open research Europe·2026

Related Experiment Video

Updated: Apr 30, 2026

Generation and Isolation of Cell Cycle-arrested Cells with Complex Karyotypes
05:22

Generation and Isolation of Cell Cycle-arrested Cells with Complex Karyotypes

Published on: April 13, 2018

13.3K

Phylogenomic analyses unravel annelid evolution.

Torsten H Struck1, Christiane Paul, Natascha Hill

  • 1University of Osnabrück, FB05 Biology/Chemistry, AG Zoology, Barbarastrasse 11, 49069 Osnabrück, Germany. struck@biologie.uni-osnabrueck.de

Nature
|March 4, 2011
PubMed
Summary

Phylogenomic analyses reveal the evolutionary history of Annelida (ringed worms), clarifying relationships between major clades like Errantia and Sedentaria. This study reconstructs the annelid tree of life, offering insights into body-plan evolution.

More Related Videos

Manipulation of Ploidy in Caenorhabditis elegans
07:54

Manipulation of Ploidy in Caenorhabditis elegans

Published on: March 15, 2018

12.1K
Semiconductor Sequencing for Preimplantation Genetic Testing for Aneuploidy
09:03

Semiconductor Sequencing for Preimplantation Genetic Testing for Aneuploidy

Published on: August 25, 2019

8.8K

Related Experiment Videos

Last Updated: Apr 30, 2026

Generation and Isolation of Cell Cycle-arrested Cells with Complex Karyotypes
05:22

Generation and Isolation of Cell Cycle-arrested Cells with Complex Karyotypes

Published on: April 13, 2018

13.3K
Manipulation of Ploidy in Caenorhabditis elegans
07:54

Manipulation of Ploidy in Caenorhabditis elegans

Published on: March 15, 2018

12.1K
Semiconductor Sequencing for Preimplantation Genetic Testing for Aneuploidy
09:03

Semiconductor Sequencing for Preimplantation Genetic Testing for Aneuploidy

Published on: August 25, 2019

8.8K

Area of Science:

  • Evolutionary Biology
  • Zoology
  • Phylogenetics

Background:

  • Annelida (ringed worms) is a diverse phylum crucial for understanding animal evolution.
  • Traditional classifications of Annelida are challenged by new evidence, necessitating a robust evolutionary framework.
  • Deep-level evolutionary relationships within Annelida remain poorly understood.

Purpose of the Study:

  • To reconstruct a well-supported phylogeny for Annelida using phylogenomic data.
  • To investigate the evolutionary history and deep-level relationships within the Annelida phylum.
  • To understand the evolution of body plans and lifestyles within Annelida.

Main Methods:

  • Phylogenomic analyses were conducted on 34 annelid taxa.
  • Utilized 47,953 amino acid positions for robust phylogenetic reconstruction.
  • Employed ancestral character trait reconstructions to infer evolutionary adaptations.

Main Results:

  • A well-supported annelid phylogeny was recovered, clarifying major splits.
  • Basal clades identified include chaetopterids, myzostomids, and sipunculids.
  • Two major clades, Errantia and Sedentaria, were resolved, showing adaptations to different lifestyles.

Conclusions:

  • The study provides a robust evolutionary framework for Annelida, including previously debated taxa.
  • Reconstructed phylogeny illuminates the evolution of errant and sedentary lifestyles and associated traits.
  • Life history characters are phylogenetically informative within Annelida, enhancing evolutionary understanding.