Features of DNA polymerase α (pol α) genes from nine spirotrichous ciliates. A schematic macronuclear DNA pol α gene is shown in the inset. This is flanked by telomeres. The inset also shows the consensus sequence of the 5' conserved motif (AATACCGCC), the transcription start site (right arrow), the putative translation start site (ATG), introns (3 found in seven stichotrichous ciliates as small grey boxes and 2 in Euplotes spp. as small hatched boxes), the putative translation termination codon (STOP), the putative polyadenylation signal sequence (poly(A)), and the mRNA polyadenylation site (solid black diamond). Although relative positions of these features are shown, they are not drawn to scale. Italicized numbers indicate intron lengths; allelic differences, when detected, are separated by "/". Numbers in the last column indicate the putative lengths (number of amino acids) of DNA pol α proteins from each species. Other numbers represent the distances from one motif to the next motif. For example, numbers in the first column represent distances from the 5' telomere to the 5' conserved motif. The symbol "#" indicates that data were not available due to the unavailability of RNA, while a dashed line ("-") indicates that the feature was not detected. Nucleotides in the 5' conserved motifs are shown as dots if they are identical to the consensus AATACCGCC. For each species, only nucleotides that differ from this consensus sequence are shown, as well as nucleotides that comprise the putative polyadenylation signal. A phylogenetic tree  is provided at the left of the figure for reference.