Mesoderm-specific B104 expression in the Drosophila embryo is mediated by internal cis-acting elements of the transposon.
The Drosophila melanogaster genome contains about 100 copies of the B104 transposable element, which is strongly expressed during embryogenesis. Here we show that B104 expression is restricted to the esophageal and amnioproctodeal regions of the embryo and to the developing mesoderm. Mesoderm-specific B104 expression requires the activity of the mesoderm-determining factors twist and snail. Virtually the same expression patterns were observed in Drosophila yakuba, a species that a separated from D. melanogaster by some 15 million years of evolution. We show that B104 expression is directed by internal sequences of the retrotransposon that are capable of acting as a cis-acting regulatory element in front of a heterologous Drosophila promoter. Our findings suggest that retrotransposon insertions can affect the expression patterns of endogenous genes by adding and distributing specific cis-acting control elements throughout the host genome. We therefore propose that transposable elements in addition to reducing the fitness of their hosts may also provide a rich pool of cis-acting sequences that contribute to the long-term evolutionary potential of the population in a beneficial manner.
Brönner
G
G
Abteilung Molekulare Entwicklungsbiologie, Max-Planck-Institut für biophysikalische Chemie, Postfach 2841, D-37018 Göttingen, Germany.
Taubert
H
H
Jäckle
H
H
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D005075:Biological Evolution; D003001:Cloning, Molecular; D004247:DNA; D004330:Drosophila / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D015686:Gene Products, env / Q000235:genetics; D008648:Mesoderm / Q000378:metabolism*; D008969:Molecular Sequence Data; D011506:Proteins / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D018626:Retroelements; D013045:Species Specificity
D029721:Drosophila Proteins; D015686:Gene Products, env; D011506:Proteins; D018626:Retroelements; C095604:roo-ORF protein, Drosophila; D004247:DNA