The preprotachykinin-1 peptides. SLNSGSSERSIAQNYE is similar to the C-terminal flanking peptide (CTFP) in mammalian protachykinin 1. Two previously unknown serine phosphorylations at positions S6 or S7 and S10 were discovered. (A) FTICR derived MS/MS spectra for single phosphorylated form (Mw 1820) at S6 or S7 and (B) S10 (Mw 1900.3). Amino acid sequence alignment (C) between chicken (continuous sequence in black color) and human (red text) preprotachykinin 1 precursor shows the differences between birds and mammals in the detected tachykinins, especially neuropeptide K (NPK). (D) Visualization of differences between the groups as calculated (Xclass-Xtot) for the hierarchical clustering in figure 1. The stars designate significance levels (*** p < 0.001, ** p < 0.01 and * p < 0.05) for the different factors in the model. a FDR adjusted p-value significance for F-test. Interaction effects were tested using Wald F-test. The last letters in the group definitions ed12/17XX stand for M = male, F = female, C = controls, E = ethinylestradiol exposed.