Membrane structures and functional correlates in the bi-segmented eye lens of the cephalopod.

The cephalopod eye lens is unique because it has evolved as a compound structure with two physiologically distinct segments. However, the detailed ultrastructure of this lens and precise optical role of each segment are far from clear. To help elucidate structure-function relationships in the cephalopod lens, we conducted multiple structural investigations on squid.

Comparative evaluation of three real-time polymerase chain reaction assays to detect Myxobolus cerebralis.

Objective: We sought to evaluate accurate and reproducible detection of Myxobolus cerebralis (Mc), the causative agent of whirling disease, by using nested polymerase chain reaction (nPCR) and three previously established real-time quantitative PCR (qPCR) assays: K18S (Kelley 18S), C18S (Cavender 18S), and Hsp70 (heat shock protein 70). We used a "fit for purpose" approach combined with intra- and interlaboratory testing to identify a molecular testing method that would be equivalent to the currently accepted nPCR procedure for Mc.

Methods: Assay performance was compared using a combination of intra- and interlaboratory testing that used synthetic gBlocks along with naturally and experimentally infected fish tissue.

Structural control of corneal transparency, refractive power and dynamics.

The cornea needs to be transparent to visible light and precisely curved to provide the correct refractive power. Both properties are governed by its structure. Corneal transparency arises from constructive interference of visible light due to the relatively ordered arrangement of collagen fibrils in the corneal stroma.

Persistence of heterologous Flavobacterium psychrophilum genetic variants in microcosms simulating fish farm and hatchery environments.

Flavobacterium psychrophilum, the causative agent of bacterial coldwater disease, causes substantial economic losses in salmonid farms and hatcheries. Some multilocus sequence types (ST) of F. psychrophilum are more likely to be associated with fish farms and hatcheries, but it is unclear if these patterns of association represent genetic lineages that are more adapted to aquaculture environments.

Varying shedding dynamics in three bacterial coldwater disease-susceptible salmonid (Family ) species.

causes bacterial coldwater disease (BCWD) and is responsible for substantial losses in farm and hatchery-reared salmonids (Family ). Although infects multiple economically important salmonids and is transmitted horizontally, the extent of knowledge regarding shedding rates and duration is limited to rainbow trout (). Concurrently, hundreds of sequence types (STs) have been described using multilocus sequence typing (MLST), and evidence suggests that some variants have distinct phenotypes, including differences in host associations.