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Origin, Composition, and Structure of the Supernumerary B Chromosome of Drosophila melanogaster
The number of chromosomes carried by an individual species is one of its defining characteristics. Some species, however, can also carry supernumerary chromosomes referred to as B chromosomes. B chromosomes were recently identified in a laboratory stock of Drosophila melanogaster—an established mode...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Genetics Society of America
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6283169/ https://www.ncbi.nlm.nih.gov/pubmed/30249684 http://dx.doi.org/10.1534/genetics.118.301478 |
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author | Hanlon, Stacey L. Miller, Danny E. Eche, Salam Hawley, R. Scott |
author_facet | Hanlon, Stacey L. Miller, Danny E. Eche, Salam Hawley, R. Scott |
author_sort | Hanlon, Stacey L. |
collection | PubMed |
description | The number of chromosomes carried by an individual species is one of its defining characteristics. Some species, however, can also carry supernumerary chromosomes referred to as B chromosomes. B chromosomes were recently identified in a laboratory stock of Drosophila melanogaster—an established model organism with a wealth of genetic and genomic resources—enabling us to subject them to extensive molecular analysis. We isolated the B chromosomes by pulsed-field gel electrophoresis and determined their composition through next-generation sequencing. Although these B chromosomes carry no known euchromatic sequence, they are rich in transposable elements and long arrays of short nucleotide repeats, the most abundant being the uncharacterized AAGAT satellite repeat. Fluorescent in situ hybridization on metaphase chromosome spreads revealed this repeat is located on chromosome 4, strongly suggesting the origin of the B chromosomes is chromosome 4. Cytological and quantitative comparisons of signal intensity between chromosome 4 and the B chromosomes supports the hypothesis that the structure of the B chromosome is an isochromosome. We also report the identification of a new B chromosome variant in a related laboratory stock. This B chromosome has a similar repeat signature as the original but is smaller and much less prevalent. We examined additional stocks with similar genotypes and did not find B chromosomes, but did find these stocks lacked the AAGAT satellite repeat. Our molecular characterization of D. melanogaster B chromosomes is the first step toward understanding how supernumerary chromosomes arise from essential chromosomes and what may be necessary for their stable inheritance. |
format | Online Article Text |
id | pubmed-6283169 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | Genetics Society of America |
record_format | MEDLINE/PubMed |
spelling | pubmed-62831692018-12-18 Origin, Composition, and Structure of the Supernumerary B Chromosome of Drosophila melanogaster Hanlon, Stacey L. Miller, Danny E. Eche, Salam Hawley, R. Scott Genetics Investigations The number of chromosomes carried by an individual species is one of its defining characteristics. Some species, however, can also carry supernumerary chromosomes referred to as B chromosomes. B chromosomes were recently identified in a laboratory stock of Drosophila melanogaster—an established model organism with a wealth of genetic and genomic resources—enabling us to subject them to extensive molecular analysis. We isolated the B chromosomes by pulsed-field gel electrophoresis and determined their composition through next-generation sequencing. Although these B chromosomes carry no known euchromatic sequence, they are rich in transposable elements and long arrays of short nucleotide repeats, the most abundant being the uncharacterized AAGAT satellite repeat. Fluorescent in situ hybridization on metaphase chromosome spreads revealed this repeat is located on chromosome 4, strongly suggesting the origin of the B chromosomes is chromosome 4. Cytological and quantitative comparisons of signal intensity between chromosome 4 and the B chromosomes supports the hypothesis that the structure of the B chromosome is an isochromosome. We also report the identification of a new B chromosome variant in a related laboratory stock. This B chromosome has a similar repeat signature as the original but is smaller and much less prevalent. We examined additional stocks with similar genotypes and did not find B chromosomes, but did find these stocks lacked the AAGAT satellite repeat. Our molecular characterization of D. melanogaster B chromosomes is the first step toward understanding how supernumerary chromosomes arise from essential chromosomes and what may be necessary for their stable inheritance. Genetics Society of America 2018-12 2018-09-24 /pmc/articles/PMC6283169/ /pubmed/30249684 http://dx.doi.org/10.1534/genetics.118.301478 Text en Copyright © 2018 by the Genetics Society of America Available freely online through the author-supported open access option. |
spellingShingle | Investigations Hanlon, Stacey L. Miller, Danny E. Eche, Salam Hawley, R. Scott Origin, Composition, and Structure of the Supernumerary B Chromosome of Drosophila melanogaster |
title | Origin, Composition, and Structure of the Supernumerary B Chromosome of Drosophila melanogaster |
title_full | Origin, Composition, and Structure of the Supernumerary B Chromosome of Drosophila melanogaster |
title_fullStr | Origin, Composition, and Structure of the Supernumerary B Chromosome of Drosophila melanogaster |
title_full_unstemmed | Origin, Composition, and Structure of the Supernumerary B Chromosome of Drosophila melanogaster |
title_short | Origin, Composition, and Structure of the Supernumerary B Chromosome of Drosophila melanogaster |
title_sort | origin, composition, and structure of the supernumerary b chromosome of drosophila melanogaster |
topic | Investigations |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6283169/ https://www.ncbi.nlm.nih.gov/pubmed/30249684 http://dx.doi.org/10.1534/genetics.118.301478 |
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