Fig. 4.

Phylogeny of Slfn genes based on neighbor-joining analysis of amino acid sequences. Only sequences that aligned unambiguously to the mouse SLFN core region (Fig. 1) were analyzed. This is an unrooted phylogram obtained using the “equal input” model implemented in MEGA 3.1 (Kumar et al., 2004). We designate four major clades ”Groups 1–4”. The pink arrow indicates the hypothesized occurrence of horizontal transfer of a Slfn gene from a rodent to the OPV ancestor. Numbers at nodes represent bootstrap support values based on 5000 pseudoreplicates. ⁎ indicates 70% or above bootstrap support (Hillis and Bull 1993). Values below 50% were removed. Scale: 0.1 indicates 10% estimated number of substitutions per position.