Molecular characterization of the cyclin-dependent protein kinase 6 in whitefish (Coregonus lavaretus) and its potential interplay with miR-34a.

Cyclin-dependent protein kinase 6 (CDK6) plays a pivotal role in the regulation of the cell cycle and cell proliferation in mammals, and disruption of its expression by various microRNAs has been implicated in the pathogenesis of multiple human cancers. In mammals, miR-34a acts as a downstream effector of p53, and thus indirectly targets Cdk6, abrogating its effects. However, no studies have been done so far to examine the mechanistic involvement of miR-34a in the silencing of cdk6 in fish.

Microcystin-LR-Triggered Neuronal Toxicity in Whitefish Does Not Involve MiR124-3p.

Microcystin-LR (MC-LR) is a potent hepatotoxin that has also been pointed out of causing neurotoxicity, but the exact mechanisms of action still remain ambiguous and need to be elucidated. Data from studies on mammals show that pathology of astrocyte cells points to perturbations of microRNA signaling. Glial fibrillary acidic protein (GFAP), a neuronal cell/astrocyte-specific protein, and a microRNA-124-3p (MiR124-3p) are among putative triggers and regulators of neuronal cell/astrocyte reactivity.

Transfer of zearalenone to the reproductive system of female rainbow trout spawners: A potential risk for aquaculture and fish consumers?

To investigate whether ZEN transfers from the alimentary tract of fish to the somatic cells of ovaries or the oocytes, mature females of rainbow trout were orally exposed to ZEN at a dose of 1 mg·kg body mass. At sampling times of 2, 6, 12, 24, 48, and 96 h, tissues of the fish (intestine, liver, ovaries, oocytes, muscles, and plasma) were extracted to determine the concentration of ZEN and its metabolites using immunoaffinity columns and HPLC-FLD. Our results confirm that ZEN is transferred from the alimentary tract to the reproductive system of the fish, and indicate that the mycotoxin concentrates in the somatic cells of the ovaries.

Intraperitoneal exposure of whitefish to microcystin-LR induces rapid liver injury followed by regeneration and resilience to subsequent exposures.

To date, there has been no systematic approach comprehensively describing the sequence of pathological changes in fish during prolonged exposure to microcystin-LR (MC-LR). Towards this aim, juvenile whitefish individuals received an intraperitoneal injection with pure MC-LR, and the injection was repeated every week to maintain continuous exposure for 28days. During the exposure period, growth and condition of the fish were assessed based on biometric measurements.

Illumina Sequencing Reveals Aberrant Expression of MicroRNAs and Their Variants in Whitefish (Coregonus lavaretus) Liver after Exposure to Microcystin-LR.

Molecular analyses show that challenging fish with microcystin-LR (MC-LR) causes perturbations of microRNA (miRNA) signaling. However, the significance and scope of these alterations is currently unknown. To address this issue, we studied miRNA gene expression in the liver of juvenile whitefish, C.