Figure 3.

Splicing of a SINEC_Cf sequence into the canine mRNA for Tipin. (A) The 5′-end of the canine Tipin gene differs from that of human by inclusion of an additional untranslated exon that is derived from a SINEC_Cf. (B) Alignment of sequences representing the 5′-ends of Tipin mRNA from human (GenBank accession no. BP248314) and dog (BM540124) with genomic sequences from human (NCBI build 34) and dog (CanFam1). Nucleotide identity between the human and dog genomic sequences is shaded, exons are boxed, and intronic sequences are in lower case. Between exons 1 and 2, the dog genome contains a SINEC_Cf sequence that is flanked by a characteristic 15-bp duplication of the insertion site (white lettering on black). This element provides a 3′-splice acceptor site, and causes activation of a cryptic 5′-splice site downstream of the element, resulting in the incorporation of the SINEC_Cf sequence within the dog Tipin mRNA.