Expression of two metallothionein genes in different brain regions of common carp

Abstract

The expression pattern of two metallothionein (MT) genes in response to temperature shock and exposure to Cd(2+) was investigated in the brain of common carp ( Cyprinus carpio ), in whole-animal experiments. The changes in the levels of MT-1 and MT-2 mRNA in the olfactory lobe, midbrain and cerebellum were followed by semiquantitative RT-PCR. The inducibility of the two MT genes was brain region and stressor-specific. Cd(2+) affected mostly the expression of MT-2, while the level of the MT-1 transcript did not change significantly in any of the brain regions examined. Moreover, the MT-2 expression was regulated spatially; MT-2 was induced significantly more strongly in the olfactory lobe than in the cerebellum or midbrain. A sudden temperature drop mainly affected the expression of the MT-1 gene; after 5 h of cold shock, the MT-1 mRNA level was about 25% of the basal value in the cerebellum and the midbrain region. The MT-2 expression did not change significantly during this treatment.

Imidacloprid exposure cause the histopathological changes, activation of TNF-α, iNOS, 8-OHdG biomarkers, and alteration of caspase 3, iNOS, CYP1A, MT1 gene expression levels in common carp (Cyprinus carpio L.)

“…Metallothioneins (MTs) can bind to zinc and copper. MTs have been shown to eliminate the adverse effects of exposure to toxic elements, including heavy metals and pesticides, and to protect organisms from several stress conditions such as oxidative stress [ [34] , [35] , [36] ]. Pesticides can induce MT synthesis in fish [ 37 ].…”

An updated review of cold shock and cold stress in fish

“…Increases in HIF2α and other hypoxia‐inducing factors are conceivable because of restricted blood flow following cold stress, which may be an adaptive response to reduce the rate of brain cooling during exposure to low temperatures (Donaldson et al ., 2008). Transcription rates of metallothionein 1 (MT‐1), but not metallothionein 2 (MT‐2), increased in common carp ( Cyprinus carpio L. 1758) olfactory bulbs, midbrains and cerebella (Ali et al ., 2009). Gene transcription associated with the production of heat shock protein 90 (HSP90, a molecular chaperone) was elevated in the brains of grass carp ( Ctenopharyngodon idella Valenciennes 1844) following acute cold shock (Wu et al ., 2012), as was stearoyl‐CoA‐desaturase 1 (SCD1) transcription in large yellow croaker ( Larimichthys crocea Richardson 1846; Xu et al ., 2015) and AMPK transcription (resulting in the production of 5′ AMP‐activated protein kinase, which plays a key role in regulating energy metabolism) in olive flounder ( Paralichthys olivaceus Temminck & Schlegel 1846; Nie et al ., 2020).…”