Fig. 8.

Graphical summary depicting the functional diversification of the uL18 RP family in Angiosperms. The uL18 protein family comprises eight members that evolved from ancestral organellar uL18 genes. Five members are transported into mitochondria and three into plastids. Two uL18 proteins (uL18m and very likely uL18c) have retained the original uL18 function and are subunits of organellar ribosomes. Among the other six uL18-Like members, uL18-L1 and uL18-L8 have evolved toward splicing and specifically associate in vivo with introns whose splicing they promote.