Figure 4. Retrotransposition of KLF14 and Mammalian Evolution.
(A) Genomic distribution of KLF14 and flanking genes is shown. KLF14 is flanked by MKLN1 and TSGA13 in human and mouse. These two genes are present in opossum, yet KLF14 is absent. In chicken, there is a syntenic break in the region, placing genes on different chromosomes. Two microRNAs (miR-29 and miR-29b-2), which lie in the fragile site adjacent to KLF14 (FRA7H), are conserved.
(B) Presence of KLF14 and KLF16 in distant mammals is shown. The lower panel shows PCR amplification of KLF16 from mammals of diverse clades, and the upper panel shows the amplification of KLF14. The mammals shown are (L-R) cow (Bos taurus), tree shrew (Tupaia glis), nine-banded armadillo (Dasypus novemcinctus), tamandua (Tamandua tetradactyla), red-necked wallaby (M. rufogriseus), and red-legged short-tailed opossum (M. brevicaudata). It indicates that KLF14 is present in eutherian, but not marsupial mammals, and shows that KLF16 is more ancient than KLF14.