The effect of 3-nitrooxypropanol, a potent methane inhibitor, on ruminal microbial gene expression profiles in dairy cows

Table 3 Changes in genes and transcripts (copies per million, CPM) encoding for methyl-coenzyme M reductase (MCR) enzyme (EC: 2.8.4.1) in the rumen of dairy cows supplemented with 3-nitrooxypropanol (3-NOP) compared to control cows at weeks 4, 8, and 12. Based on raw reads and based on metagenome assembled genomes (MAGs). K00399, alpha subunit of MCR; K00401, beta subunit of MCR; K00402, gamma subunit of MCR

MCR genes identification based on raw reads
	Metagenomics
	W4			W8			W12
	Control	3-NOP	% reduction	Control	3-NOP	% reduction	Control	3-NOP	% reduction	Treatment P value
K00399	265	213	20	306	230	25	227	253	−11	0.18
K00401	245	178	27	239	163	32	169	192	−14	0.18
K00402	253	197	22	293	223	24	210	251	−20	0.22
2.8.4.1	763	588	23	838	616	26	606	697	−15	0.12
Metatranscriptomics
K00399	2756	2578	6	3656	2548	30	2667	2333	13	0.15
K00401	2135	1781	17	2529	1606	36	1885	1415	25	0.001
K00402	2679	2908	−9	3946	2905	26	2829	2571	9	0.64
EC:2.8.4.1	7570	7268	4	10131	7059	30	7381	6320	14	0.06
MCR gene identification based on MAGs
Metagenomics
K00399	32	33	−3	49	47	5	36	51	−42	0.47
K00401	52	43	17	55	37	33	38	42	−11	0.10
K00402	142	92	35	88	41	54	69	54	22	0.06
EC:2.8.4.1	75	56	26	64	42	35	48	49	−3	0.07
Metatranscriptomics
K00399	411	507	−24	777	607	22	596	591	1	0.92
K00401	537	565	−5	877	570	35	681	545	20	0.08
K00402	1282	988	23	1276	816	36	891	605	32	0.02
EC:2.8.4.1	743	687	8	977	664	32	723	580	20	0.01

\(\mathrm{Percent}\ \mathrm{reduction}=\frac{\left(\mathrm{Control}\right)-\left(3-\mathrm{NOP}\right)}{\left(\mathrm{Control}\right)}\ \mathrm{X}\ 100\)

ISSN: 2049-2618