Table 2.

The number of clustered miRNAs and isolated miRNAs found in the human, mouse and rat genomes using our definition of miRNA cluster.

		Human	Mouse	Rat
Version of miRBase		10.0	10.0	10.1
Total # of clusters		60	55	48
Size of clusters	Min	2	2	2
	Mean	4	4.31	3.04
	Max	43	52	17
Isolated miRNAs	#	288	220	154
	%	54.55%	48.14%	51.33%
Clustered miRNAs	#	240	237	146
	%	45.45%	51.86%	48.67%
Total # of miRNAs		528	457	300

"Version of miRBase" denotes the update version of miRBase where the datasets are downloaded. "Size of clusters" is equivalently to the number of miRNAs found in a single cluster. There are 60, 55 and 47 clusters identified in the three genomes respectively, which are equivalent to 45.45%, 51.86% and 48.67% of the total human, mouse and rat miRNAs.