Diversity and evolution of mammalian lysozyme-like genes. A phylogeny, adapted from recent phylogenomic analyses [71-73], of the mammalian species examined in this study is shown; branch lengths are not proportional to evolutionary time. The numbers of each type of lysozyme-like gene identified in the mammalian genomes are shown by symbols on the right of the Figure. Species with genomes of higher quality (better coverage and assembly) are labeled in bold and with asterisks. The status of the genes in each genome are indicated by symbols, listed in the key box in the figure, where solid boxes indicate genes that are predicted to encode full-length sequences, open boxes indicate incomplete genes, which may be due to either incomplete genome sequences or may be pseudogenes, the Greek letter psi identifies well-characterized pseudogenes, zero indicates that no gene was identified in our searches, and the 'not' sign indicates genes that appear to have been deleted from the genomes. The question mark beside the sloth Lyzl8 gene indicates that this is a tentative assignment. Inferred evolutionary events are mapped onto their most likely lineage, based upon the data presented in this figure, coupled with our various evolutionary analyses. Duplication of genes is indicated by a gene name with an arc over it. Gene deletion is indicated by an X preceding the name of the deleted gene. X? means that the deletion is uncertain, as the missing gene may actually exist in a gap in the descendant genome(s). Pseudogene generation is indicated by the psi (ψ) that precedes the gene name; if the pseudogene is associated with a gene duplication event it also has an arc. If multiple events are shown on a lineage, the order shown does not imply historical order of occurrence.
Irwin et al. BMC Evolutionary Biology 2011 11:166 doi:10.1186/1471-2148-11-166