Porter and Bailey: Using measurements of muscle cell nuclear RNA to assess larval condition of Gadus chalcogrammus 
343 
30,000 
24,500 
19,000 
13,500- 
8,000 
10 10 
Nuclear RNA fluorescence 
30,000 
10 10 
Nuclear RNA fluorescence 
Figure 3 
Scatter plots of cell-cycle analysis by flow cytometry of muscle cell nuclei of (A) an 
always-fed larva (fed 4 days) and (B) an unfed larva (starved 14 days) of Walleye 
Pollock (Gadus chalcogrammus) reared in 2009. The rectangles outlined in black 
indicate the gates used to determine the number of Gl-phase nuclei with elevated 
nuclear RNA content needed to enter the S phase (GIB), and the total number of 
nuclei in the S phase of the cell cycle (S). The G1 phase of the cell cycle is when 
cell growth occurs before cell division, and the S phase is when DNA replicates. The 
always-fed larva had a distinct group of S-phase nuclei, and, for the unfed larva, 
S-phase nuclei were fewer and dispersed. Fluorescence values are arbitrary units. 
RNASelect stain concentration and DAPI+2000-nM 
Syto RNASelect stain concentration were significant- 
ly higher than the values for the DAPI+500-nM Syto 
RNASelect stain concentration (ANOVA, Fo igp 165.94, 
P <0.001; Tukey’s test, P<0.01 for both stain concentra- 
tions; Fig. 4A), but there was no significant difference 
in fluorescence between them (ANOVA, F (3 ig)=165.94, 
P<0.001; Tukey’s test, P=0.44; Fig. 4A). 
There was no significant difference in DNA fluores- 
cence between the control and the 500-nM and 1000- 
nM Syto RNASelect stain concentrations (ANOVA, 
F(3,19)=10.90, P<0.001; Dunnett’s test, P= 0.57 and 
