title: Differential time-series expression of immune-related genes of Pacific white shrimp Litopenaeus vannamei in response to dietary inclusion of beta-1,3-glucan.
abstract: Time-series changes in transcript abundance of nine genes encoding important immune proteins in haemocytes or hepatopancreas of Pacific white shrimp Litopenaeus vannamei fed daily in a 1-week feeding trial diets containing three levels (0%, 0.2% or 1%) of beta-1,3-glucan from Schizophyllum commune were quantified by real-time PCR. As a whole, the immune modulation elicited by beta-glucan is bimodal, one swift reaction of up- or down-regulation occurred within 24h and a delayed regulation was commenced as late as 3-7days. Haemocyanin, crustin, prophenoloxidase (proPO) and transglutaminase (TGase) did not respond to the glucan treatment. While penaeidin 3 (Litvan PEN3) was swiftly down-regulated (0-24h), lysozyme and cytosolic manganese superoxide dismutase (cMnSOD) were swiftly up-regulated (0-24h). In contrast, the two pattern recognition proteins (PRPs), beta-glucan binding protein-high density lipoprotein (BGBP-HDL) and lipopolysaccharide/beta-glucan binding protein (LGBP), showed a delayed up-regulation. Their expressions were not maximized until as late as 72h or 7days, respectively, which coincide with the initiation of reported immune enhancement (6-24days) of PO and SOD activity, phagocytosis and superoxide anion production in penaeid shrimp receiving glucan-containing diet. These immune responses could be the downstream effects of the two PRP gene up-regulation that predispose the shrimp to a state of high immune responsiveness. Increased dosage of beta-glucan from 2 to 10gkg(-1) diet did not affect the expressions of the genes, indicating the sufficiency of beta-glucan supplementation at 2gkg(-1) diet.
authors.affiliation: Institute of Marine Biology, National Sun Yat-sen University, Kaohsiung 804, Taiwan.
authors.forename: Yu-Chi
authors.initials: YC
authors.lastname: Wang
authors.forename: Poh-Shing
authors.initials: PS
authors.lastname: Chang
authors.forename: Houng-Yung
authors.initials: HY
authors.lastname: Chen
mesh_terms: D000818:Animals; D005786:Gene Expression Regulation / Q000187:drug effects*; D006434:Hemocytes / Q000187:drug effects; D043143:Hepatopancreas / Q000187:drug effects; D033561:Penaeidae / Q000187:drug effects* / Q000235:genetics / Q000276:immunology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D047071:beta-Glucans / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D012333:RNA, Messenger; D047071:beta-Glucans; C033363:beta-1,3-glucan