Genes expressed in Japanese flounder Paralichthys olivaceus spleen: analysis of genes involved in immune function

Abstract

Expressed sequence tag (EST) analysis is an efficient tool for gene discovery and for profiling gene expression. A cDNA library developed from messenger RNA of the Japanese flounder, Paralichthys olivaceus spleen was constructed by directional cloning, in order to isolate functional genes involved in immunity in fish. A total of 1010 ESTs from the library were sequenced and compared with sequences in the GenBank database. Of the 1010 ESTs, 618 ESTs (61%) were identified as being homologous with known genes from many organisms by BLAST searches, whereas 392 (39%) appeared to be unknown and are likely to represent newly described genes. Of the identified genes, 105 (17%) encoded proteins associated with cell/organism defence and homeostasis. Of these 105 genes, 21 were identified for the first time in Japanese flounder. These included macrophage inflammatory protein (MIP)-3 α, granulin-A, novel immune-type receptor (NITR), interferon regulatory factor (IRF)-10, presenilin-like protein-2, and antizyme inhibitor. A comparison of ESTs derived from spleen, kidney, liver and leukocytes suggested that expression of immune-related genes in different tissues, organs, or cells are different.KEY WORDS: cDNA sequence, expressed sequence tag, Japanese flounder, spleen.

Dietary low or excess levels of lipids reduced growth performance, and impaired immune function and structure of head kidney, spleen and skin in young grass carp (Ctenopharyngodon idella) under the infection of Aeromonas hydrophila

“…Based on the quadratic regression analysis for PWG (Y PWG ¼ À0.0378 x 2 þ 3.3064x þ 158.96, R 2 ¼ 0.861), the dietary lipids requirement of young grass carp is estimated to be 43.7 g/kg diet. Fish growth is often related to disease resistance, which has been correlated with immune organ function [4]. Hence, we next investigated the effects of lipids on the head kidney and spleen immune function in young grass carp.…”

“…It has been reported that the head kidney and spleen are the major sites of antibacterial compounds production to protect fish from pathogens in teleosts, which include lysozyme (LA), acid phosphatase, complement and antimicrobial peptides [4,75,76]. In the present study, compared to the optimal dietary lipids supplement, low or excess levels of lipids decrease LA and ACP activities and C3, C4 and IgM contents and down-regulate LEAP-2a, LEAP-2b, Hepcidin and b-defensin-1 mRNA levels in the head kidney and spleen of young grass carp, indicating that low or excess levels of lipids could reduce the immune function in the head kidney and spleen of fish.…”

“…To our knowledge, fish growth is positively related to disease resistance [3]. Arma et al [4] reported that fish disease resistance is related to immune response, which partly relies on the function and structure of immune organs. Fish skin is an important immune organ that is postulated to be the site of pathogens entry to the other organs and tissues (such as the lymphatic immune organs) [5].…”

“…3 Low or excess levels of lipids trigger the inflammatory response by up-regulating pro-inflammatory cytokines IL-1b, TNF-a, IL-8, IL-15b, IL-12 p40 (not p35), TNF-a and IFN-g2 mRNA levels, as well as down-regulating anti-inflammatory cytokines IL-6, IL-4(13)A, IL-4(13)B, IL-10, IL-11 TGF-b1 and TGF-b2 mRNA levels in the head kidney and spleen, which could be partly regulated by several signalling molecules, such as NF-kB p65 (not p52), IkBa, IKKb, IKKg, TOR, S6K1 4EBP 1 and 4EBP 2 in the head kidney and spleen of fish. 4 Low or excess levels of lipids could decrease young grass carp immunity by declining the antibacterial compounds including LA, ACP, IgM, C3, C4 and antimicrobial peptides. 5 Low or excess levels of lipids increase the skin haemorrhage and lesions.…”

The adenosinergic system, not the cholinergic system, exerts an anti-inflammatory profile in lymphatic immune organs of fish naturally infected with Ichthyophthirius multifiliis

“…Fish disease resistance is linked to the immune response, which partly relies on the proper function and structure of immune organs, such as the head kidney and spleen, two important lymphatic immune organs (Arma et al, 2005;Seker et al, 2011). In this…”