The DNA puff BhB10-1 gene encodes a glycine-rich protein secreted by the late stage larval salivary glands of Bradysia hygida.
We present the molecular characterization of a gene of Bradysia hygida DNA puff B10 whose temporal expression in the salivary gland correlates with the puff expansion. The transcription unit of this gene, named BhB10-1, was mapped in a 2-kb EcoRI genomic fragment that is amplified in the salivary gland of late fourth instar larvae. Its 1.3-kb transcript undergoes poly-A tail shortening during development, indicating that post-transcriptional controls as well as transcription activation are involved in the temporal regulation of the BhB10-1 gene. Analysis of the deduced amino acid sequence from the cDNA indicates that the BhB10-1 protein is a glycine-rich secretory protein. A BhB10-1-fusion protein expressed in bacteria was used to raise polyclonal antibodies. Using an immunopurified antibody, we identified the product of the DNA puff BhB10-1 gene as a 23-kDa polypeptide that is produced mainly by the salivary gland regions S1 and S3 and is present in the saliva of late larvae. This is the first direct identification of a protein encoded by a DNA puff amplified gene.
Fontes
A M
AM
Departamento de Morfologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, CEP 14049-900, Ribeirão Preto, Brazil.
Conacci
M E
ME
Monesi
N
N
de Almeida
J C
JC
Paçó-Larson
M L
ML
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004247:DNA; D018076:DNA, Complementary; D017344:Genes, Insect; D005998:Glycine / Q000032:analysis*; D019476:Insect Proteins; D007313:Insecta / Q000196:embryology / Q000235:genetics*; D007814:Larva / Q000378:metabolism*; D008969:Molecular Sequence Data; D012469:Salivary Glands / Q000196:embryology / Q000378:metabolism*; D012471:Salivary Proteins and Peptides / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
D018076:DNA, Complementary; D019476:Insect Proteins; C119619:PB10 protein, Bradysia hygida; D012471:Salivary Proteins and Peptides; D004247:DNA; D005998:Glycine