Yh. Lee et Ll. Keeley, HYPERTREHALOSEMIC HORMONE EFFECTS ON TRANSCRIPTIONAL ACTIVITY IN THE FAT-BODY OF THE COCKROACH, BLABERUS-DISCOIDALIS, Insect biochemistry and molecular biology, 24(4), 1994, pp. 357-362
Gene expression was examined in the fat body of adult male Blaberus di
scoidalis, cockroaches in response to the hypertrehalosemic hormone (H
TH). HTH regulates a natural peak of heme synthesis in the fat body at
day 4 of adult life. Inhibition of transcriptional activity by alpha-
amanitin suppressed both the natural increase in heme biosynthesis at
day 4, and the increase that was induced in decapitated animals by HTH
administration. In contrast, the regimen of alpha-amanitin treatments
that suppressed HTH-responsive heme biosynthesis had no effect on the
ability of HTH to increase hemolymph carbohydrate. HTH administration
to decapitated animals produced a 25% increase in total fat body RNA
and a 3-fold increase in [H-3]uridine incorporation. In vitro translat
ion of fat body RNA showed that HTH increased the synthesis of polypep
tides at 24, 60 and 77 kDa. The results suggest that HTH affects fat b
ody heme synthesis through gene expression, and evidence was obtained
for three polypeptides that increase in the fat body in response to HT
H.