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...
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...
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.
Chromosomal Theory of Inheritance01:39

Chromosomal Theory of Inheritance

In 1866, Gregor Mendel published the results of his pea plant breeding experiments, providing evidence for predictable patterns in the inheritance of physical characteristics. The significance of his findings was not immediately recognized. In fact, the existence of genes was unknown at the time. Mendel referred to hereditary units as “factors.”
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...

You might also read

Related Articles

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

Sort by
Same author

Cryptic diversity and recent diversification in the Pyrrhulina australis species complex (Characiformes, Lebiasinidae) revealed by mitochondrial DNA.

Journal of fish biology·2026
Same author

Satellitome analysis of the black soldier fly Hermetia illucens reveals genome organization, interstocks dynamics, and insights into centromeric and telomeric repeat composition.

BMC biology·2026
Same author

Effects of anthropogenic influences in the DNA methylation and expression of genes involved in the metabolism of Geophagus surinamensis from the Pará River (Amazon, Brazil).

Ecotoxicology (London, England)·2026
Same author

Cytogenetics of Neotropical fishes: Patterns, advances and prospects after five decades of research.

Genetics and molecular biology·2026
Same author

Editoŕs corner: repetitive DNA landscapes in the era of large-scale genomic datasets and data integration.

Gene·2026
Same author

Genome assembly of Astatotilapia latifasciata uncovers B chromosome-linked chromatin reorganization.

Heredity·2026

Related Experiment Video

Updated: Jun 12, 2026

Preparation of Meiotic Chromosome Spreads from Zebrafish Spermatocytes
08:46

Preparation of Meiotic Chromosome Spreads from Zebrafish Spermatocytes

Published on: March 3, 2020

Chromosome differentiation patterns during cichlid fish evolution.

Andréia B Poletto1, Irani A Ferreira, Diogo C Cabral-de-Mello

  • 1Departamento de Morfologia, Universidade Estadual Paulista, Instituto de Biociências, Botucatu, SP, Brazil.

BMC Genetics
|June 17, 2010
PubMed
Summary

Cichlid fish chromosome evolution reveals distinct karyotype markers for African and American subfamilies. Chromosomal rearrangements and ribosomal RNA gene mapping provide insights into cichlid diversity and evolution.

More Related Videos

2D and 3D Chromosome Painting in Malaria Mosquitoes
09:57

2D and 3D Chromosome Painting in Malaria Mosquitoes

Published on: January 6, 2014

Dissection of Larval Zebrafish Gonadal Tissue
10:43

Dissection of Larval Zebrafish Gonadal Tissue

Published on: April 26, 2017

Related Experiment Videos

Last Updated: Jun 12, 2026

Preparation of Meiotic Chromosome Spreads from Zebrafish Spermatocytes
08:46

Preparation of Meiotic Chromosome Spreads from Zebrafish Spermatocytes

Published on: March 3, 2020

2D and 3D Chromosome Painting in Malaria Mosquitoes
09:57

2D and 3D Chromosome Painting in Malaria Mosquitoes

Published on: January 6, 2014

Dissection of Larval Zebrafish Gonadal Tissue
10:43

Dissection of Larval Zebrafish Gonadal Tissue

Published on: April 26, 2017

Area of Science:

  • Ichthyology
  • Cytogenetics
  • Evolutionary Biology

Background:

  • Cichlid fishes exhibit rapid adaptive radiation and ecological diversity.
  • They are crucial for tropical and subtropical aquaculture.
  • Understanding chromosome evolution is key to cichlid research.

Purpose of the Study:

  • To investigate chromosome evolution in cichlid species.
  • To analyze karyotypes of Asian, African, and South American cichlids.
  • To review chromosomal data for the cichlid family.

Main Methods:

  • Karyotype analysis of 33 cichlid species (1 Asian, 22 African, 30 South American).
  • Review of existing chromosomal data for the cichlid family.
  • Cytogenetic mapping of the 18S ribosomal RNA (18S rRNA) gene.

Main Results:

  • Modal chromosome numbers differ between South American (2n=48) and African (2n=44) cichlids.
  • The Asian species Etroplus maculatus has 46 chromosomes.
  • 18S rRNA gene mapping showed 2-6 clusters, varying among species.
  • Karyotype markers identified for African Pseudocrenilabrinae and American Cichlinae subfamilies.

Conclusions:

  • Karyotype diversification in cichlids is attributed to chromosomal rearrangements (fissions, fusions, inversions).
  • Karyotype analysis successfully discriminated major Pseudocrenilabrinae groups (tilapiine, haplochromine).
  • 18S rRNA gene evolution did not consistently track chromosome diversification or phylogenetic relationships.