Overlapping Lsp-2 gene sequences target expression to both the larval and adult Drosophila fat body.
Larval serum protein-2 gene (Lsp-2) of Drosophila melanogaster encodes one of the major hexameric haemolymph proteins of third-instar larvae and a major component of adult serum. Regulated transcription of Lsp-2 results in high-level, ecdysone-stimulated expression throughout the larval fat body and low-level, spatially restricted expression in the adult fat cells. To localize cis-acting regulatory sequences responsible for the stage- and tissue-specific activity at Lsp-2, the expression of Lsp-2-lacZ fusion genes was studied by P element-mediated germline transformation of Drosophila. A 230 base pair larval enhancer, which includes an ecdysone response element (EcRE), specifically targets gene activity to the larval fat body. Although the adult mode of Lsp-2 expression depends on the larval enhancer, additional negative regulatory elements dictate both tissue-specificity and unique spatial restriction within the adult fat body. Implications of these findings for the identification of fat body-specific gene regulatory units in other insects are discussed.
Benes
H
H
Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, 72205 , USA.
Neal
K C
KC
Willis
R L
RL
Gadde
D
D
Castleberry
A B
AB
Korochkina
S E
SE
D000818:Animals; D001483:Base Sequence; D004247:DNA; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D004742:Enhancer Elements, Genetic; D005216:Fat Body; D005260:Female; D018507:Gene Expression Regulation, Developmental; D005807:Genes, Overlapping; D007301:Insect Hormones / Q000235:genetics*; D007763:Lac Operon; D007814:Larva / Q000235:genetics; D008969:Molecular Sequence Data; D012045:Regulatory Sequences, Nucleic Acid
D029721:Drosophila Proteins; D007301:Insect Hormones; C034648:larval serum protein, Drosophila; D004247:DNA