FIG. 5.

Decreased keratin gene expression (A), protein abundance (B), and attenuated STAT3 signaling pathway (C) in the skin of adult homozygous thrab 1-bp insertion (m/m) mutant fish. (A) The expression of keratin genes (krt4, krt5, krt15, krt17, and krt18) and skin-regulated genes (col1a1b, cyt1, and cki) from the belly skin of fish with genotypes indicated was determined by RT-qPCR as described in Materials and Methods section (number of fish = 22–25). (B-I) Total protein extracts were prepared from skin on the belly and Western blot analysis for keratin-5, -17, -18 and GAPDH as described in Materials and Methods section. (B-II) Quantitative analysis of relative protein abundance of keratin-5 (a), keratin-17 (b), and keratin-18 (c) from the belly skin of fish with genotypes indicated (number of fish = 10). (C-I) Western blot analysis of p-STAT3 (Tyr705), total STAT3, and downstream STAT3 target proteins [cyclinD1, CDK6, p-Rb (Ser 780), total-Rb] and GAPDH from the belly skin of fish with genotypes indicated. (C-II) Quantitative analysis of relative protein expression levels of the ratio of p-STAT3 to total STAT3 (a), p-Rb to total Rb (d), and relative level of cyclin D1 (b) and CDK6 (c) using GAPDH as a loading control (number of fish = 10). The data are expressed as mean ± SE (n = 3–6; the p-values are indicated). Two-tail unpaired t-test, p-adjusted <0.05 was used for statistical analysis.