Regulation of midgut defensin production in the blood-sucking insect Stomoxys calcitrans.
The Stomoxys midgut defensin (Smd) family of genes are exclusively expressed in the anterior midgut of adult flies. Their putative function is protection of the stored bloodmeal from microbial attack. Smd genes are constitutively expressed, up-regulated in response to a bloodmeal and further up-regulated by immune stimulation per os but only in the presence of a bloodmeal not a sugar meal. Smd genes are down-regulated in response to a systemic immune challenge. Smd gene constructs transfected into l(2)mbn cells undertake constitutive expression but are not up-regulated by immune challenge. Electrophoretic mobility shift assays (EMSA) suggest the rel-like sites in the proximal promoter region of Smd genes do not bind midgut factors and so are non-functional.
Munks
R J
RJ
School of Biological Sciences, University of Wales, Bangor LL57 2UW, Wales, UK.
Hamilton
J V
JV
Lehane
S M
SM
Lehane
M J
MJ
D000818:Animals; D000890:Anti-Infective Agents; D003001:Cloning, Molecular; D023082:Defensins / Q000096:biosynthesis* / Q000235:genetics; D004064:Digestive System / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D015870:Gene Expression; D017930:Genes, Reporter; D019476:Insect Proteins / Q000096:biosynthesis* / Q000235:genetics; D009117:Muscidae / Q000235:genetics / Q000254:growth & development; D011401:Promoter Regions, Genetic; D017422:Sequence Analysis, DNA
D000890:Anti-Infective Agents; D023082:Defensins; D019476:Insect Proteins; C108780:Smd1 protein, insect; C108781:Smd2 protein, Stomoxys calcitrans