Repetitive sequences of the tree shrew genome (Mammalia, Scandentia)

Copies of two repetitive elements of the common tree shrew (Tupaia glis) genome were cloned and sequenced. The first element, Tu III, is a ～260 bp long short interspersed element (SINE) with the 5′ end derived from glycine RNA. Tu III carries long polypurine-and polypyrimidine-rich tracts, which may contribute to the specific secondary structure of Tu III RNA. This SINE was also found in the genome of the smooth-tailed tree shrew of another genus (Dendrogale). Tu III appears to be confined to the order Scandentia since it was not found in the DNA of other tested mammals. The second element, Tu-SAT1, is a tandem repeat with a monomer length of 365 bp. Some properties of its nucleotide sequence suggest that Tu-SAT1 is a centromeric satellite.