Fig 1: Lipopolysaccharide (LPS) challenge reduces milk protein expression in the mammary gland. Mammary tissues treated with PBS or LPS for 12 or 24 h (n = 8) were collected and analyzed by real-time PCR for (a–c) mRNA expression and Western blot for protein levels ((d–f) quantitative presentation and (g) representative images in which each lane was a tissue sample from a different animal except the protein size ladder in the middle lane) of (a and d) β-casein (Csn2), (b and e) α-lactalbumin (Lalba), and (c and f) α-S1-casein (Csn1s1). Relative mRNA expression was calculated by the 2-ΔΔCt method and normalized by the expression of housekeeping genes Actb, Gapdh, Hrpt, Stx5a, and Hnrnpab. In (d)–(f), relative protein levels of milk proteins were normalized by the levels of GAPDH (d). Error bars represent standard error, and different letters above each bar indicate significant differences. Significance was declared when P < 0.05.