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Hypertrehalosemic hormone‐regulated gene expression for cytochrome P4504C1 in the fat body of the cockroach, Blaberus discoidalis
Author(s) -
Lu KuangHui,
Bradfield James Y.,
Keeley Larry L.
Publication year - 1995
Publication title -
archives of insect biochemistry and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.576
H-Index - 66
eISSN - 1520-6327
pISSN - 0739-4462
DOI - 10.1002/arch.940280107
Subject(s) - biology , gene expression , cockroach , cycloheximide , gene , transcription (linguistics) , cytochrome p450 , hormone , adipokinetic hormone , messenger rna , microbiology and biotechnology , endocrinology , genetics , protein biosynthesis , fat body , metabolism , ecology , linguistics , philosophy
Hypertrehalosemic hormone (HTH) up‐regulates expression of a gene for a cytochrome P450 of family 4 ( CYP4C1 ) in the fat body of adult male B. discoidalis cockroaches. Studies were undertaken to determine the characteristics of HTH‐dependent CYP4C1 expression. A dot‐blot assay was developed for routine measurement of the relative levels of CYP4C1‐mRNA in fat body RNA extracts. A single injection of 10 pmol HTH produced a maximum CYP4C1 response within 8 h. This dose corresponds with the dose needed for a maximum in vivo hypertrehalosemic response to HTH (Keeley et al., 1991). Multiple treatments with HTH at 8 or 24 h intervals were no more effective than a single treatment for producing CYP4C1 expression. These results indicate that CYP4C1 expression is sensitive to physiological doses of HTH and responds rapidly. CYP4C1 expression was suppressed by treatment with α‐amanitin, an inhibitor of RNA polymerase II, but was unaffected by cycloheximide, an inhibitor of protein synthesis. HTH appears to influence CYP4C1 transcription without involvement of intervening regulatory genes. These results suggest that regulation of fat body CYP4C1 expression is a major physiological action of HTH. © 1995 Wiley‐Liss, Inc.