Transcriptomic buffering of cryptic genetic variation contributes to meningococcal virulence

BMC Genomics

Table 2 Significantly enriched COG functional categories in cross-condition and cross-strain comparisons

	Non-directional^(a)		Directional^(b)
COG functional category	OR^(c)	FDR^(d)	OR^(e)	FDR^(d)
MC58 cross-condition comparisons
Saliva ↔ Blood
Nucleotide transport and metabolism (COG F)	2.66	0.044	n.s.	n.s.
Energy metabolism and conversion (COG C)	n.s.	n.s.	0.18	0.024
Cell wall/membrane/envelope biogenesis (COG M)	n.s.	n.s.	0.31	0.020
Posttranslational modification, protein turnover, chaperones (COG O)	n.s.	n.s.	0.13	0.023
Not in COG	n.s.	n.s.	6.53	<0.001
Blood ↔ CSF
Not in COG	n.s.	n.s.	0.06	<0.001
MC58 versus α522 cross-strain comparisons
Blood
Energy metabolism and conversion (COG C)	2.25	0.008	11.6	<0.001
Cell wall/membrane/envelope biogenesis (COG M)	n.s.	n.s.	0.19	<0.001
Saliva ↔ Blood
Energy metabolism and conversion (COG C)	2.99	<0.001	>5.33	<0.001
Translation, ribosomal structure and biogenesis (COG J)	n.s.	n.s.	0.04	<0.001
Cell wall/membrane/envelope biogenesis (COG M)	n.s.	n.s.	0.09	0.003
Blood ↔ CSF
Energy metabolism and conversion (COG C)	3.27	<0.001	n.s.	n.s.

^(a) Comparison of differently versus non-differently expressed genes to identify COG categories that are affected by differential expression in general
^(b) Comparison of differentially expressed genes to identify COG categories that are significantly affected by regulation in a distinct direction (gene expression asymmetry)
^(c) Odds ratios based on Fisher’s exact test. Values greater than 1 indicate that significantly differentially expressed genes are enriched for genes from the corresponding COG functional class
^(d) False discovery rate based on p-values from Fisher’s exact test and the Benjamini-Hochberg multiple testing correction with a significance cut-off of FDR < 0.05
^(e) For cross-condition comparisons, values greater than 1 indicate that genes highly expressed in blood were enriched for the respective COG category. In cross-strain comparisons, values greater than 1 indicate that the respective COG category is significantly highly expressed or upregulated in strain MC58

ISSN: 1471-2164