Figure 10

Patterns of emergence and loss of UULs in selected animals and in M. brevicollis. This figure summarizes the most parsimonious hypothesis to explain the patterns of emergence and loss of UUL-encoding genes in selected species. Arrows indicate gene emergences and rectangles, gene losses. UBE4-like and WDSUB1-like refer to the presence of genes which encode proteins similar in sequence but different in structure to the canonical vertebrate proteins. Lophotrochozoan data are still quite fragmentary and some groups may have lost UUL-encoding genes.