Organization and possible origin of the Bari-1 cluster in the heterochromatic h39 region of Drosophila melanogaster.
The molecular organization of the heterochromatic h39 region of the Drosophila melanogaster second chromosome has been investigated by studying two BAC clones identified both by Southern blotting and by FISH experiments as containing tandem arrays of Bari1, a transposable element present only in this region. Such BAC clones appear to contain different portions of the h39 region since they differ in the DNA sequences flanking the Bari1 repeats on both sides. Thus, the 80 Bari1 copies estimated to be present in the h39 region are split into at least two separated subregions. On the basis of the analysis of the flanking sequences a possible mechanism depending on an aberrant activity of the Bari1 transposase is proposed for the genesis of the heterochromatic tandem arrays of the element.
Dipartimento di Anatomia Patologica e di Genetica, Sezione di Genetica, Università di Bari. Via G. Amendola 165/A, 70126 Bari, Italy.
René Massimiliano
RM
Marsano
Rosabella
R
Milano
Crescenzio
C
Minervini
Roberta
R
Moschetti
Corrado
C
Caggese
Paolo
P
Barsanti
Ruggiero
R
Caizzi
D000818:Animals; D015139:Blotting, Southern; D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial; D004251:DNA Transposable Elements / Q000235:genetics*; D004331:Drosophila melanogaster / Q000235:genetics*; D006570:Heterochromatin / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D020080:Tandem Repeat Sequences
D004251:DNA Transposable Elements; D006570:Heterochromatin