Fig. 2
From: Identification and characterization of microRNAs involved in ascidian larval metamorphosis
Evolutionary history of tunicate miRNAs. C. savignyi miRNAs were compared with miRNAs of 16 other animal species from miRBase. Only miRNAs supported by experimental evidence were used. An miRNA family was defined as acquired at the origin of a taxon if it is shared by at least two daughter lineages of the taxon but if is absent in all ancestor and sister lineages. At the base of each taxon, numbers are shown for the miRNA families acquired (+) and lost (−) during the origin of this taxon. A number is also given in parentheses to indicate the acquired families that are present in C. savignyi (not lost in evolution)