Fig. 1

Genomic distribution of grass carp miRNAs and miRNA phylogeny in Chordata. A Distribution of miRNA genes in the genome of C.idella. Tracks from outside in Track 1: 24 linkage groups of the genome. Track 2: Name of miRNAs (prefix “miR-” was omitted). Track 3: miRNA loci, clustered miRNAs at adjacent positions are displayed in a stacked style. Track 4: miRNA expression (normalized count), from inside out: muscle, intestine, heart, hatching stage, gill, brain. B Birth and death rates of miRNA families. Twelve animal species were used in the study, and estimated rates of miRNA families gain and loss, as inferred by parsimony procedure, are shown. Branch lengths reflect evolutionary divergence times per million years inferred from timetrees (http://www.timetree.org/). The number of gained ( +) and lost ( −) families and the rates of miRNA family gain per million years (MY) (in red) are indicated next to each branch. Each species' total number of families is shown before its name. C The physical locations of miRNAs in the grass carp genome