Table 1.

miRNA expression profiles.

		C-C	C-HF	HF-C	HF-HF
miRNAs (N)		417	380	446	440
MAX/MIN	MEAN	2.6	3.5	3.2	2.2
	STD	2.9	6.1	4.2	1.6
	MEAN + 2 STD	8.3	15.7	11.6	5.5
	miRNAs with MAX/MIN >8.3 (N)	15	21	25	6
	miRNAs with MAX/MIN >8.3 (%)	3.6	5.5	5.6	1.4
CV	MEAN	0.28	0.29	0.32	0.24
	STD	0.18	0.16	0.20	0.13

Statistics. Expression profiles of male adult ARCs display complex populations of 380–446 miRNAs. We analyzed the variation of expression of each miRNA between the six profiles of groups C-C, C-HF, HF-C, or HF-HF by calculating its maximal to minimal ratio (MAX/MIN) and standard deviation to mean ratio (coefficient of variation; CV). Only a minor fraction of the miRNA population of each group displays MAX/MIN values higher than the value of 8.3 that corresponds to mean + 2 STD in group C-C: 1.1, 3.6, 5.5, and 5.6% in groups HF-HF, C-C, C-HF, and HF-C, respectively. Extensive intra-group homogeneity of miRNA expression in all groups is an important feature for sound analyses of inter-group differential expression.