High impact information on Pig1

• In this paper, we show that three adjacent elements located within the short region between these genes can account for the switch from Pig-1 to Sgs-4 expression [1].
• The Pre-intermoult gene-1 (Pig-1) of Drosophila melanogaster maps on the X chromosome, at polytene bands 3C11-12, and is nested within the 79 kb intron of the dunce gene [2].
• We also report that the level of Pig-1 transcript is nearly fourfold reduced in a variant strain carrying a deletion within the Pig-1 upstream sequence, thus identifying a regulatory element required for high level gene expression [2].
• The corresponding gene is active only in larval salivary glands and, therefore, is named gland specific gene, gsg [3].
• Point mutations that disrupt this site had no significant effect on activation of the Sgs-4 promoter in constructs lacking the Pig-1 promoter [4].

Biological context of Pig1

• The Drosophila genes Pig-1 and Sgs-4 are adjacent and oppositely transcribed genes which share a common enhancer region located in the intergenic region between the two transcription start sites [4].
• The transcriptional switch between the Drosophila genes Pig-1 and Sgs-4 depends on a SEBP1 binding site within a shared enhancer region [4].

Anatomical context of Pig1

• Pig-1 and Sgs-4 are a pair of closely linked and divergently transcribed Drosophila melanogaster genes, which are both expressed in larval salivary glands but at different times during development [1].

References