Figure 4.

Hypothesis on horizontal transfer in evolution of Loc-103275158. BLAST match of the orf segments as shown in Figure. 1, suggest intermediate species as hosts for protozoan vectors of the tigger TE. Thus, the 5′-block matches the T.gondii TGVEG to IF-2 in C. lanigera, which could have passed the HCG4-tigger block into T. syrichta via T. gondii. The 3′-block is suggested to involve P. reticulata, wherein the CK1b footprint matches an uncharacterized orf of Hammondia (a close relative of T. gondii). Ostensibly, this would require protozoan:protozoan transfer from a fish protozoan to Hammondia, which could have then infected T. syrichta. The red arrows indicate possible gene conversions in T. syrichta leading to the symmetrical, MHC central location in the orf.