Molecular characterization of SINES integrated in endogenous retrovirus sequences from Leopardus geoffroyi and Puma concolor / Molecular characterization of SINES integrated in endogenous retrovirus sequences from Leopardus geoffroyi and Puma concolor

ABSTRACT

Background: Short interspersed nuclear elements (SINEs) are transposable elements which are transcribed by RNA polymerase III and widespread in mammalian genomes. Can-SINE is a family of SINE sequences specific to carnivores, predominant in their genomes and present in high copy numbers. The aim of this study was to characterize sequences of Can-SINEs integrated into sequences of endogenous retroviruses (ERVs) from Brazilian wild cats Puma concolor and Leopardus geoffroyi. Additionally, these sequences are considered from some perspectives of their evolution. Material, Methods and Results: By using PCR and sequencing to screen for ERVs within the genomes of L. geoffroyi and P. concolor, two new ERV sequences were amplified with an insertion around 220 nucleotides long, similar to published carnivore SINEs. The sequences were further identified and characterized using a combination of BLAST, BLAT searches and phylogenetic analyses. The results showed that SINE sequences integrated into the ERV from P. concolor (SINE_Pco) and L. geoffroyi (SINE_Lg) are lysine-tRNA derived. These sequences presented a typical RNA polymerase III-specific internal promoter sequence followed by a microsatellite region (TC)n and by an A/T-rich tail with the polyadenylation signal AATAAA. BLAST searches using the whole sequence of L. geoffroyi clone as query (ERV plus SINE) detected two sequences which

RESUMO

Background: Short interspersed nuclear elements (SINEs) are transposable elements which are transcribed by RNA polymerase III and widespread in mammalian genomes. Can-SINE is a family of SINE sequences specific to carnivores, predominant in their genomes and present in high copy numbers. The aim of this study was to characterize sequences of Can-SINEs integrated into sequences of endogenous retroviruses (ERVs) from Brazilian wild cats Puma concolor and Leopardus geoffroyi. Additionally, these sequences are considered from some perspectives of their evolution. Material, Methods and Results: By using PCR and sequencing to screen for ERVs within the genomes of L. geoffroyi and P. concolor, two new ERV sequences were amplified with an insertion around 220 nucleotides long, similar to published carnivore SINEs. The sequences were further identified and characterized using a combination of BLAST, BLAT searches and phylogenetic analyses. The results showed that SINE sequences integrated into the ERV from P. concolor (SINE_Pco) and L. geoffroyi (SINE_Lg) are lysine-tRNA derived. These sequences presented a typical RNA polymerase III-specific internal promoter sequence followed by a microsatellite region (TC)n and by an A/T-rich tail with the polyadenylation signal AATAAA. BLAST searches using the whole sequence of L. geoffroyi clone as query (ERV plus SINE) detected two sequences which