A) The phylogenetic tree of Rif1 homologues. The simplified version of the phylogenetic tree of Rif1 homologues (The detailed tree is shown in the Additional file 2). A common branching is seen in three major classes (Fungi, Invertebrates and Vertebrates) and the number of organisms from each branch having the Rif1 homologues is mentioned in the parentheses. B) The conserved domains of Rif1 homologues. The conserved domains of Rif1 homologues of human, fly and yeast are shown. The protein length is mentioned below the organism name. The conserved domains are highlighted in different shapes (SILK/PP1 interaction domain – diamond, DNA binding domain –oval (Horizontal), BLM interaction domain –rectangle, HEAT repeat – oval (vertical) and the core conserved region of HEAT repeat is highlighted in grey). The motifs are mapped approximately to the scale.