Methane yield phenotypes linked to differential gene expression in the sheep rumen microbiome

Phylogenetic analysis of methanogens in sheep rumen. (A) A phylogenetic tree constructed based on full-length methyl coenzyme M reductase alpha subunit (McrA/MrtA) protein sequences. Known McrA/MrtA proteins from NCBI are shown in black; new ones from this study, in color. (B) Genes and transcripts for three groups of identified sheep rumen methanogens. (RPM) Reads per million; (NS) no statistical significance in Wilcoxon rank-sum test; (*) P < 0.05; (**) P < 0.01. Error bars, SE. (C) Relative contribution of each group of sheep rumen methanogens to the overall abundance (RPM) of genes and transcripts in low and high CH₄ yield sheep. The sizes of each pie indicate the abundance of genes/transcripts.