Response of phase I and II detoxification enzymes, glutathione, metallothionein and acetylcholine esterase to mercury and dimethoate in signal crayfish (Pacifastacus leniusculus).

Metals and pesticides are common pollutants and the modulation of biomarkers can indicate sub-lethal influences on the physiology of organisms inhabiting impacted aquatic systems. We examined the effects of mercury and the organophosphate pesticide dimethoate on EROD, MROD, glutathione S-transferase (GST), acetylcholine esterase (AChE), metallothionein (MT) and glutathione (GSH) in the signal crayfish (Pacifastacus leniusculus). Crayfish were injected with mercury chloride or dimethoate (0.

Prophage-mediated defence against viral attack and viral counter-defence.

Temperate phages are common, and prophages are abundant residents of sequenced bacterial genomes. Mycobacteriophages are viruses that infect mycobacterial hosts including Mycobacterium tuberculosis and Mycobacterium smegmatis, encompass substantial genetic diversity and are commonly temperate. Characterization of ten Cluster N temperate mycobacteriophages revealed at least five distinct prophage-expressed viral defence systems that interfere with the infection of lytic and temperate phages that are either closely related (homotypic defence) or unrelated (heterotypic defence) to the prophage.

Function, expression, specificity, diversity and incompatibility of actinobacteriophage parABS systems.

More than 180 individual phages infecting hosts in the phylum Actinobacteria have been sequenced and grouped into Cluster A because of their similar overall nucleotide sequences and genome architectures. These Cluster A phages are either temperate or derivatives of temperate parents, and most have an integration cassette near the centre of the genome containing an integrase gene and attP. However, about 20% of the phages lack an integration cassette, which is replaced by a 1.