Fig 4. Relative mRNA expression of barrier function and nutrient sensing genes in different segments of intestinal mucosa in chickens injected in ovo with GOS.

The panel includes genes encoding mucin, (A) MUC6; tight junctions components, (B) CLDN1 and (C) TJAP1; free fatty acid receptors, (D) FFAR2 and (E) FFAR4; and glucose transporters, (F) GLUT1, (G) GLUT2 and (H) GLUT5. Intestinal segments: DUO–duodenum, JEJ–jejunum, ILE–ileum and CEC–caecum. In ovo treatment groups: control (white bars)–injected in ovo with physiological saline; GOS (black bars)–injected in ovo with galactooligosaccharides. In ovo injection was carried out on day 12 of egg incubation. Intestinal samples (n = 10) were collected from chickens on day 42 post-hatching. RT-qPCR data were generated with custom-designed primers used for amplification with SYBR green dye; Glucose-6-phosphate dehydrogenase (G6PDH) and beta-actin (ACTB) were used as reference genes; relative gene expression calculated as 2^–ΔΔCt; Two-way ANOVA with a post hoc HSD Tukey test was used to compare the groups. Asterisk indicates pair-wise significant differences (P < 0.05). The results of fold induction less than 1 have been transformed by the formula -1/fold induction.