Methylation and expression dynamics in broiler liver following in-ovo sodium butyrate administration.

Butyrate is one of the three main short-chain fatty acids, and it provides energy, controls the state of the intestinal microbiota and mediates the immune response. Sodium butyrate supplementation improves poultry production and changes the intestinal microbiota dynamically. These changes may affect the liver directly and indirectly through pathways in the gut-liver axis, the bidirectional relationship between the liver and intestines. The study analysed gene expression and methylation in the broiler liver after in-ovo stimulation by sodium butyrate. Incubated Ross 308 broiler eggs were injected on day 12 with saline as the control group or with sodium butyrate as SB groups at three doses: 0.1%, 0.3% and 0.5%. Chicks' livers were collected postmortem on day 42 of rearing for RNA and DNA extraction. Gene expression was analysed by reverse-transcription qPCR, and gene methylation by methylation-specific qPCR for a panel of lipid metabolism and immune regulation genes comprising ANGPTL4, CD72, CXCR5, CYR61, IKZF1, KLHL6, NR4A3, SERPING, SYK and TNFRSF14. Sodium butyrate stimulation changed gene expression levels. Upregulation was noted of ANGPTL4 and NR4A3 in the 0.1% and 0.3% SB groups and downregulation of CYR61 in the 0.5% SB group. The gene-specific DNA methylation also significantly changed under the influence of the sodium butyrate doses for ANGPTL4, CXCR5 and KLHL6. The level of global methylation did not change significantly, but did decrease with increasing butyrate dose. The obtained results suggest that sodium butyrate affected both gene expression and methylation in the liver, indicating its potential epigenetic effects.