Heat shock proteins are not
sensitive indicators of hatchery stress in salmon
J. Zarate, T.M. Bradley-2003
Aquaculture, 223(1-4): 175-187
Abstract:
An array of physiological, endocrinological,
biochemical and behavioral indicators have been investigated for utility in
assessing the level of stress imposed on cultured finfish by rearing
conditions and husbandry practices. In the present report, juvenile Atlantic
salmon (Salmo salar) were exposed to common forms of hatchery stress
and the response of heat shock proteins (hsp) 30, 70 and 90 were measured as
possible indicators of stress. Treatments included exposure to two types of
anesthesia (tricaine methanesulfonate and 2-phenoxyethanol), formalin,
hypoxia, hyperoxia, capture stress, crowding, feed deprivation and cold
stress. Exposure of fish to heat stress at 26 °C (ΔT=11 °C)
served as a positive control, and untreated fish were used as a negative
control. Total RNA was isolated from gill tissue following treatment, and
subjected to Northern analysis with cDNA probes specific to the three hsps.
Hsp70 and Hsp90 mRNA levels increased three-fold and two-fold above control
levels, respectively, following 15-min heat stress. hsp30 mRNA levels were
unaffected by 15-min exposure to heat stress, but increased two-fold over
control levels following 30-min exposure. In contrast, Hsp mRNA was not
upregulated in response to the different hatchery stresses examined.
Although cold stress, crowding and capture stress caused an increase in
hsp90 mRNA levels, these were not significant. The findings suggest that
hsp30, hsp70 and hsp90 are not sensitive indicators of hatchery stress in
Atlantic salmon.