A novel Giraffidae-specific interspersed repeat with a microsatellite, originally found in an intron of a ruminant paralogous p97bcnt gene.

The ruminant-specific p97bcnt gene (bcntp97) is a paralogous gene that includes a region derived from a retrotransposable element 1 (RTE-1). The region comprises an exon (RTE-1 exon) encoding 325 amino acids in the middle of the p97bcnt protein. To understand how the bcntp97 paralog evolved, we examined its organization in several ruminants. We found a 700-base pair (bp) insert in the 5′ intron of the RTE-1 exon in giraffe bcntp97. This insert is missing in the corresponding regions of bovine and sika deer. Furthermore, the sequence of the insert is interspersed in the genome of giraffe but not bovine and also contains a (GA)n microsatellite. A highly homologous insert harboring significantly different (GA)n microsatellite was detected in the corresponding region of okapi bcntp97. Therefore, the interspersed fragments with (GA)n microsatellite might serve as a marker for tracking how duplicated genes evolve in a family-specific manner.