Journal article
The fourth chromosome of Drosophila melanogaster: Interspersed euchromatic and heterochromatic domains
Proceedings of the National Academy of Sciences - PNAS, Vol.97(10), pp.5340-5345
04/25/2000
DOI: 10.1073/pnas.090530797
PMCID: PMC25830
PMID: 10779561
Abstract
The small fourth chromosome of
Drosophila melanogaster
(3.5% of the genome) presents a puzzle. Cytological analysis suggests that the bulk of the fourth, including the portion that appears banded in the polytene chromosomes, is heterochromatic; the banded region includes blocks of middle repetitious DNA associated with heterochromatin protein 1 (HP1). However, genetic screens indicate 50–75 genes in this region, a density similar to that in other euchromatic portions of the genome. Using a P element containing an
hsp70
-
white
gene and a copy of
hsp26
(marked with a fragment of plant DNA designated
pt
), we have identified domains that allow for full expression of the
white
marker (R domains), and others that induce a variegating phenotype (V domains). In the former case, the
hsp26
-
pt
gene shows an accessibility and heat-shock-inducible activity similar to that seen in euchromatin, whereas in the latter case, accessibility and inducible expression are reduced to levels typical of heterochromatin. Mapping by
in situ
hybridization and by hybridization of flanking DNA sequences to a collection of cosmid and bacterial artificial chromosome clones shows that the R domains (euchromatin-like) and V domains (heterochromatin-like) are interspersed. Examination of the effect of genetic modifiers on the variegating transgenes shows some differences among these domains. The results suggest that heterochromatic and euchromatic domains are interspersed and closely associated within this 1.2-megabase region of the genome.
Details
- Title: Subtitle
- The fourth chromosome of Drosophila melanogaster: Interspersed euchromatic and heterochromatic domains
- Creators
- Fang-Lin Sun - Washington University in St. LouisMatthew H. CuaycongCarolyn A. CraigLori L. WallrathJohn LockeSarah C. R. Elgin
- Resource Type
- Journal article
- Publication Details
- Proceedings of the National Academy of Sciences - PNAS, Vol.97(10), pp.5340-5345
- DOI
- 10.1073/pnas.090530797
- PMID
- 10779561
- PMCID
- PMC25830
- NLM abbreviation
- Proc Natl Acad Sci U S A
- ISSN
- 0027-8424
- eISSN
- 1091-6490
- Publisher
- National Academy of Sciences
- Language
- English
- Date published
- 04/25/2000
- Academic Unit
- Biochemistry and Molecular Biology; University College Courses
- Record Identifier
- 9984293075602771
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