Tissue-specific expression of two metallothionein genes in common carp during cadmium exposure and temperature shock

Characteristics, functions, and applications of metallothionein in aquatic vertebrates

“…And the role of MTs in nervous tissue of vertebrates has been suggested (Kramer et al, 1996;Tallkvist et al, 2002). Cd was the most potential for MTs induction among three metals (i.e., Cd, Cu, and Zn) in H. mylodon, and this outcome was consistent with previous discoveries that Cd was one of very powerful inducers for metallothionein transcription in fish (De Smet et al, 2001;Hermesz et al, 2001;Chan et al, 2006;Cho et al, 2008). It had been also suggested that transcriptional regulation of metallothionein in the fingerings of this species should be very sensitive to Cd, and any potential harmful stress to this species origin from the Cd pollution at much lower concentration than 0.1 mM in wild habitats may be detected by tracing the MTs expression in fingerlings if the exposure is extended (Cho et al, 2008).…”

Metallothionein-2 gene from the mandarin fish Siniperca chuatsi: cDNA cloning, tissue expression, and immunohistochemical localization

“…In previous reports, MT gene mRNA expression has often been proposed as a sensitive and efficient biomarker for evaluating the cumulative biological effects of metal exposure in the tissues of a wide range of aquatic species, e.g., the common carp (C. carpio) (Hermesz et al, 2001), brown trout (Salmo trutta) (Linde et al, 1999), and gudgeons (G. gobio) (Knapen et al, 2007). Further, it was considered useful for evaluating metal exposure in both laboratory and field studies (Viarengo et al, 1999;Fernandes et al, 2008) by using either common RT-PCR or real-time PCR.…”

“…Since fish are susceptible to metal contamination in water, MT can be used as a biomarker of metal ion contamination. Therefore, considerable efforts have been focused on the use of MT for monitoring metal contamination in water or in fish (Hermesz et al, 2001;Van Der Oost et al, 2003;Tom et al, 2004;Amado et al, 2006;Wu et al, 2007). However, tissue MT levels and metal contents in fish are influenced by age, season, sex, and species, e.g., in the flounder (Platichthys flesus), hepatic MT had the highest levels during the autumn in a year and increased significantly with age; in the mature female squirrelfish (Holocentrus adsencscionis), the MT mRNA and protein level increased at the onset of sexual maturation compared to immature females and males; the milkfish (Chanos chanos) had a higher tolerance to Cd exposure than either tilapia (Oreochromis mossambicus) or Acrossocheilus paradoxus (Goksoyr et al,1996;Hylland et al, 1998;Rotchell et al, 2001; Thompson et al, 2002;Wu et al, 2007).…”

“…Thus far, only 2 MT isoforms (MT-1 and MT-2) have been found and could be induced by exposure to metal ions in many species of fish such as the common carp (C. carpio) (Hermesz et al, 2001), icefish (Chionodraco hamatus) (Scudiero et al, 2001), and pike (Esox lucius) (Kille et al, 1993). In mammals, MT-1 is polypeptides with a higher degree of cysteine conservation compared to t MT-2 (Miles et al, 2000).…”

Activation of gene expression by metal-responsive signal transduction pathways.

“…Exposure to metals, organic chemicals, physical stress, intracellular damage, and physiologic agents causes an increase the steady-state level of MT mRNA (5,(37)(38)(39)(40). In addition, several of these nonmetal stressors activate MT transcription via MREs (10,22,41,42).…”