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Immunofluorescence Analysis of Endogenous and Exogenous Centromere-kinetochore Proteins
Published on: March 3, 2016
Uncoupling of satellite DNA and centromeric function in the genus Equus
Francesca M Piras1, Solomon G Nergadze, Elisa Magnani
1Dipartimento di Genetica e Microbiologia Adriano Buzzati-Traverso, Università di Pavia, Pavia, Italy.
Plos Genetics
|February 20, 2010
Summary
Centromere repositioning in horse evolution is common. Centromeres can function without satellite DNA, which is acquired later in centromere evolution, as shown in Equus species.
Area of Science:
- Genetics
- Evolutionary Biology
- Molecular Cytogenetics
Background:
- Centromere repositioning, a shift in centromeric function without DNA rearrangement, occurs frequently in Equus evolution.
- Previous studies indicated frequent centromere repositioning events in the horse genus.
Purpose of the Study:
- To investigate the relationship between satellite DNA and centromere function during evolution in Equus.
- To analyze the chromosomal distribution of satellite DNA in various horse species.
- To understand the maturation process of evolutionary new centromeres (ENCs).
Main Methods:
- Chromosomal analysis of satellite tandem repeat distribution in four Equus species.
- Immuno-FISH experiments using satellite DNA and anti-CENP-A antibodies.
- Phylogenetic reconstruction of centromere repositioning events.
Main Results:
- Several centromeres, including ENCs, were found to be devoid of satellite DNA.
- Satellite repeats were observed at non-centromeric termini, potentially representing inactive centromere relics.
- Immuno-FISH confirmed that satellite-less primary constrictions possess centromeric function.
- Phylogenetic analysis revealed that satellite DNA acquisition follows centromere formation and can be absent for millions of years.
Conclusions:
- Centromeres can function effectively without satellite DNA for extended evolutionary periods.
- Satellite DNA is acquired after centromere formation, indicating a non-essential role in initial centromere establishment.
- Equus species provide a model for studying intermediate stages in the evolution of new centromeres.
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