Table 2.

Individual amounts, sum and ratio of gill Na+/K+-ATPase isoforms α1a and α1b mRNA from Atlantic salmon, Arctic char and rainbow trout acclimated to freshwater or seawater for up to 30 days

Days in freshwater (control) Days in seawater
SpeciesIsoform1301241030
Arctic charα1a1.58±0.511.20±0.320.58±0.140.32±0.05ND0.51±0.200.73±0.12
α1b1.22±0.311.21±0.334.49±0.59*8.59±0.63*ND12.63±2.88*8.41±1.62*
α1a+α1b2.81±0.822.42±0.635.08±0.518.91±0.64a,b,cND13.15±2.68a,b,c9.15±2.45a,b
α1b:α1a0.82±0.061.04±0.1510.12±1.8030.91±6.81a,b,cND36.03±14.62a,b,c11.41±2.65
Atlantic salmonα1a0.90±0.200.99±0.11NDND0.08±0.020.17±0.060.20±0.03
α1b1.52±0.422.62±0.68*NDND3.93±0.42*6.48±1.01*4.83±0.76*
α1a+α1b2.43±0.573.61±0.79NDND4.01±0.446.65±1.07a5.03±0.76
α1b:α1a1.89±0.592.49±0.53δNDND52.99±7.08a,b51.20±10.90a,b28.41±7.91
Rainbow troutα1a2.79±0.251.72±0.43ND0.47±0.050.54±0.120.19±0.040.28±0.06
α1b4.18±0.771.75±0.33ND29.34±6.11*21.86±5.54*24.52±4.24*31.53±12.42*
α1a+α1b6.97±0.843.46±0.54ND29.80±6.1222.40±5.5324.71±4.2431.81±12.44b
α1b:α1a1.55±0.291.47±0.60ND64.46±11.0849.40±13.05140.71±33.65a,b120.86±36.97a,b
  • ND, not determined (species not sampled on that day).

    Individual isoform mRNA levels are relative to that of the control gene EF1α.

    Values are mean ± s.e.m.; sample size ranged from 5 to 8, and is listed in Results.

    Comparisons made over the time series for each isoform for each species as shown in Figs 3, 4, 5.

  • * α1b level is significantly different (P<0.05) from corresponding α1a level.

  • a,b,c Significantly different (P<0.05) from corresponding freshwater 1 day, freshwater 30 day and seawater 1 day groups, respectively. δLevel is significantly higher (P<0.05) than the corresponding 30 day freshwater Arctic char group.