Figure 9
From: Expansion of a novel endogenous retrovirus throughout the pericentromeres of modern humans
K222 provirus in the genomes of Old World monkeys, primates and humans. (A) Phylogenetic neighbor-joining tree of K222 integration sequences amplified from the DNA of baboon, orangutan, gorilla, chimpanzee, and human. The tree is unrooted, with taxa arranged for a balanced shape. The tree was constructed using the Kimura 2-parameter model. The stability of branches was evaluated by bootstrap tests with 10,000 replications. The scale bars represent the nucleotide substitutions per sequence. (B) Nucleotide sequence alignment of K222 insertion sequences amplified from the genomes of Old World monkeys, primates, and humans. The sequences are compared to the olive baboon sequence, which is the oldest germline sequence. Dots indicate nucleotide similarities to the master sequence. Nucleotide substitutions are indicated in letters. Several nucleotide insertions can be seen in the sequence of K222 in the orangutan, but not other primates or humans (B), which cause the divergence of the orangutan K222 in the phylogenetic tree (A), suggesting that these insertions arose only during the evolution of modern orangutans.