Increased expression of metabolism and lysosome-associated genes in a cuticle furrow mutant.

The collagen-based epidermal 'cuticle' of functions as an extracellular sensor for damage that regulates genes promoting osmotic balance, innate immunity, and detoxification. Prior studies demonstrate that SKN-1 , an ortholog of the mammalian Nrf transcription factors, activates core detoxification genes downstream from cuticle damage. Prior RNAseq data suggested that expression of five genes with functions in redox balance, ATP homeostasis, and lysosome function ( , , , , and ) were increased in a cuticle collagen mutant; this study employed RT-qPCR to verify this observation and to test the role of SKN-1 .

Compensation for hypercapnia by a euryhaline elasmobranch: effect of salinity and roles of gills and kidneys in fresh water.

Specimens of the euryhaline elasmobranch, Dasyatis sabina were acclimated to seawater and fresh water, and exposed to normocapnic (air) and hypercapnic (1% CO2 in air) environmental water. Blood pH, PCO2, and [HCO3-], as well as whole-animal net-acid excretion, were measured for up to 24 h of hypercapnia. In a separate experimental series, urine was collected from freshwater acclimated stingrays during 8 h of normocapnia and hypercapnia.