Fig. 1.

RIG-I is absent in the Chinese tree shrew. (A) Diagram illustrating the structure of the tree shrew RIG-I genomic region. Color codes: pink shading, homologous genes from human to tree shrew; gray shading, tree shrew RIG-I deficient region relative to human alignment. The green arrows indicated the primers for amplifying the fragment containing the predictive start codon of the RIG-I gene. (B) PCR amplification of the RIG-I gene fragment using the cDNAs of human HeLa (lane 1), Malayan flying lemur (lane 2) cells, and Chinese tree shrew primary renal cells (lane 3). Lane M refers to DNA ladder. (C) Western blot showing the RIG-I protein in human, monkey, mouse, and Chinese tree shrew tissues. RIG-I antibodies recognized the C terminus and the N terminus of RIG-I, respectively.