A transposable element inserted just 5′ to a Drosophila glue protein gene alters gene expression and chromatin structure

摘要: The Drosophila Sgs-4 gene directs the developmentally regulated production of a glue protein in salivary glands mature larvae. Previous work suggests that expression requires remote upstream region becomes hypersensitive to DNAase I digestion when is active. Here we describe variant locus has 1.3 kb DNA insert separating from region. This defines new family transposable elements call hobo. Expression reduced 50 100 fold, and rather than one, normal transcript, there are now four transcripts, two starting within hobo element. These multiple transcripts still expressed only late larval glands, implying developmental regulation unaffected by changes site transcript initiation. When active, I-hypersensitive region, even more due insert, forms over its sequences. In contrast, sites form near starts transcripts.