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

Lampbrush Chromosomes01:51

Lampbrush Chromosomes

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 resemble the...
Lampbrush Chromosomes01:51

Lampbrush Chromosomes

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 resemble the...
Evolutionary Relationships through Genome Comparisons02:54

Evolutionary Relationships through Genome Comparisons

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...
Synteny and Evolution02:31

Synteny and Evolution

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 chromosome underwent...
Karyotyping01:17

Karyotyping

Describing the number and physical features of chromosomes can reveal abnormalities that underlie genetic diseases. This description is facilitated by special staining techniques that produce a particular banding pattern on each chromosome. State-of-the-art techniques make this approach even more powerful, enabling the detection of individual genes that cause disease.A Simple Chromosome Staining Technique Provides Valuable Scientific InsightSome genetic diseases can be detected by looking at...
Gene Evolution - Fast or Slow?02:05

Gene Evolution - Fast or Slow?

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...

You might also read

Related Articles

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

Sort by
Same author

Transposable element and host silencing activity in gigantic genomes.

Frontiers in cell and developmental biology·2023
Same author

Genome size drives morphological evolution in organ-specific ways.

Evolution; international journal of organic evolution·2022
Same author

Gigantic Genomes Provide Empirical Tests of Transposable Element Dynamics Models.

Genomics, proteomics & bioinformatics·2021
Same author

Forever young: Linking regeneration and genome size in salamanders.

Developmental dynamics : an official publication of the American Association of Anatomists·2020
Same author

Miniaturization, Genome Size, and Biological Size in a Diverse Clade of Salamanders.

The American naturalist·2020
Same author

Reflections on Bateson's rule: Solving an old riddle about why extra legs are mirror-symmetric.

Journal of experimental zoology. Part B, Molecular and developmental evolution·2019
Same journal

Combining ultrastructure expansion microscopy with immunofluorescence and Oligopaint DNA FISH.

Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology·2026
Same journal

Bridging methodological gaps in avian cytogenetics: comprehensive and optimized protocols for chromosomal preparation in birds.

Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology·2026
Same journal

The role of satellite DNA-enriched heterochromatic variants in reproductive disorders: Insights from standardized cytogenetic analysis.

Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology·2026
Same journal

Cytogenomics of Myloplus tiete reveals conserved satellite DNAs since the Late Eocene in Serrasalmidae (Teleostei, Characiformes).

Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology·2026
Same journal

Stable resynthesized Brassica napus lines show similar meiotic behaviour to established B. napus.

Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology·2026
Same journal

Characterization of neocentromeric marker chromosome derived from chromosome 11: a rare entity in four patients with acute leukemia.

Chromosome research : an international journal on the molecular, supramolecular and evolutionary aspects of chromosome biology·2026
See all related articles

Related Experiment Video

Updated: Jul 7, 2026

Isolation of Giant Lampbrush Chromosomes from Living Oocytes of Frogs and Salamanders
10:07

Isolation of Giant Lampbrush Chromosomes from Living Oocytes of Frogs and Salamanders

Published on: December 5, 2016

Evolutionary cytogenetics in salamanders.

Stanley K Sessions1

  • 1Department of Biology, Hartwick College, Oneonta, NY, 13820, USA. sessionss@hartwick.edu

Chromosome Research : an International Journal on the Molecular, Supramolecular and Evolutionary Aspects of Chromosome Biology
|February 23, 2008
PubMed
Summary
This summary is machine-generated.

Salamander cytogenetics reveal distinct karyotype evolution patterns and significant genome size variation. These variations correlate with phenotypic, biogeographic, and phylogenetic traits, offering insights into Urodele evolution.

More Related Videos

Generation of Chimeric Axolotls with Mutant Haploid Limbs Through Embryonic Grafting
07:17

Generation of Chimeric Axolotls with Mutant Haploid Limbs Through Embryonic Grafting

Published on: January 29, 2020

Simultaneous Whole-cell Recordings from Photoreceptors and Second-order Neurons in an Amphibian Retinal Slice Preparation
11:39

Simultaneous Whole-cell Recordings from Photoreceptors and Second-order Neurons in an Amphibian Retinal Slice Preparation

Published on: June 1, 2013

Related Experiment Videos

Last Updated: Jul 7, 2026

Isolation of Giant Lampbrush Chromosomes from Living Oocytes of Frogs and Salamanders
10:07

Isolation of Giant Lampbrush Chromosomes from Living Oocytes of Frogs and Salamanders

Published on: December 5, 2016

Generation of Chimeric Axolotls with Mutant Haploid Limbs Through Embryonic Grafting
07:17

Generation of Chimeric Axolotls with Mutant Haploid Limbs Through Embryonic Grafting

Published on: January 29, 2020

Simultaneous Whole-cell Recordings from Photoreceptors and Second-order Neurons in an Amphibian Retinal Slice Preparation
11:39

Simultaneous Whole-cell Recordings from Photoreceptors and Second-order Neurons in an Amphibian Retinal Slice Preparation

Published on: June 1, 2013

Area of Science:

  • Comparative genomics
  • Evolutionary biology
  • Cytogenetics

Background:

  • Salamanders (Urodela) exhibit diverse karyotypes, with some families showing high variation in chromosome number and structure, while others remain conserved.
  • They possess exceptionally large genomes with substantial interspecific variation in DNA content and chromosome size.

Purpose of the Study:

  • To review and synthesize current knowledge on karyological and genome size variation patterns in salamanders.
  • To discuss these patterns within an evolutionary framework.

Main Methods:

  • Literature review of cytogenetic studies on salamanders.
  • Analysis of existing data on chromosome number, size, shape, and genome size across Urodele families.

Main Results:

  • Identified a dichotomy in karyotype evolution: one group with high chromosome variation, another with conserved features, supporting 'karyotypic orthoselection'.
  • Documented extensive genome size variation in salamanders, exceeding that of chromosome number and shape.
  • Correlations between genome size variation and phenotypic, biogeographic, and phylogenetic factors were noted.

Conclusions:

  • Karyotype evolution in salamanders is characterized by distinct patterns, potentially driven by 'karyotypic orthoselection'.
  • Genome size variation is a significant evolutionary factor in salamanders, with demonstrable biological relevance.
  • The relatively small number of Urodele families facilitates broad-scale evolutionary analyses.