Expression profiles of TVS genes in mouse tissues. TVS mRNA levels in the mouse brain (B), muscle (M), lung (Lu), spleen (S), heart (H), liver (Li), kidney (K), and testis (T) were analyzed by semiquantitative RT-PCR, as shown in Fig. 2. Nearly ubiquitous expression was detected for the genes Gm2a, Naif1, Parp12, Parp11, and Art5. Art2b mRNA is expressed in the lung, spleen, and liver at high levels. Rsad2 mRNA is abundantly expressed in the lung, spleen, heart, and kidney. High levels of Crlf3 mRNA are expressed in the lung and spleen.