Induction of tyrosine hydroxylase gene expression by bacteria in the fat body of eri-silkworm, Samia cynthia ricini.
A cDNA clone encoding tyrosine hydroxylase (TH) was isolated from larval fat body of immunized Samia cynthia ricini. In naive larvae, the TH gene was expressed only in the brain, but strongly induced in fat body and hemocytes after injecting UV-killed bacteria. The induction of the gene was rather short-lived compared to that of antibacterial protein genes, reaching the maximum levels 6h after bacterial challenge, and then quickly diminished. A strong induction of the gene expression was caused by both Gram-negative and positive bacteria and zymosan, but little if any by soluble peptidoglycan or lipopolysaccharide. A possible role of TH in the fat body of bacteria-challenged larvae would be to supply catecholamines as the substrate for phenoloxidase leading to melanization, working together with dopa decarboxylase.
Hashimoto
Kazuhiko
K
Department of Biochemistry and Biotechnology, Faculty of Agriculture, Tottori University, Tottori 680-8553, Japan.
Yamano
Yoshiaki
Y
Morishima
Isao
I
D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000378:metabolism*; D001483:Base Sequence; D012831:Bombyx / Q000201:enzymology* / Q000382:microbiology*; D002473:Cell Wall / Q000378:metabolism; D002999:Clone Cells; D018076:DNA, Complementary / Q000302:isolation & purification; D004790:Enzyme Induction; D005216:Fat Body / Q000201:enzymology* / Q000382:microbiology*; D020869:Gene Expression Profiling; D008969:Molecular Sequence Data; D009928:Organ Specificity; D016415:Sequence Alignment; D013997:Time Factors; D014446:Tyrosine 3-Monooxygenase / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics
D018076:DNA, Complementary; D014446:Tyrosine 3-Monooxygenase