Expression levels of Bmal1 and Per2 genes (A,C) and associated proteins (B,D) in NK cells separated from animals at different time points in DD following either control or shifted paradigms. Representative immunoblots are shown above respective protein plots across all CTs. Densitometric quantification of protein levels was done by Image J software. Sine wave fits using linear harmonic regression with an assumed period of 24 h for control and shifted groups (solid and dotted lines, respectively) are superimposed with group means ± SEMs for each CT. All curve fits are significant (p < 0.01). *, p < 0.05, significant difference between groups at CT.