title: Identification of baboon microRNAs expressed in liver and lymphocytes.
abstract: BACKGROUND
  MicroRNAs (miRNAs) are small noncoding RNAs (~22 nucleotides) that regulate gene expression by cleaving mRNAs or inhibiting translation. The baboon is a well-characterized cardiovascular disease model; however, no baboon miRNAs have been identified. Evidence indicates that the baboon and human genomes are highly conserved; based on this conservation, we hypothesized that comparative genomic methods could be used to identify baboon miRNAs.
  
  
  METHODS
  We employed an in silico comparative genomics approach and human miRNA arrays to identify baboon expressed miRNAs in liver (n = 6) and lymphocytes (n = 6). Expression profiles for selected miRNAs in multiple tissues were validated by RT-PCR.
  
  
  RESULTS
  We identified in silico 555 putative baboon pre-miRNAs, of which 41% exhibited 100% identity and an additional 58% shared more than 90% sequence identity with human pre-miRNAs. Some of these miRNAs are primate-specific and are clustered in the baboon genome like human miRNA clusters. We detected expression of 494 miRNAs on the microarray and validated expression of selected miRNAs in baboon liver and lymphocytes by RT-PCR. We also observed miRNA expression in additional tissues relevant to dyslipidemia and atherosclerosis. Approximately half of the miRNAs expressed on the array were not predicted in silico suggesting that we have identified novel baboon miRNAs, which could not be predicted using the current draft of the baboon genome.
  
  
  CONCLUSIONS
  We identified a subset of baboon miRNAs using a comparative genomic approach, identified additional baboon miRNAs using a human array and showed tissue-specific expression of baboon miRNAs. Our discovery of baboon miRNAs in liver and lymphocytes will provide resources for studies on the roles of miRNAs in dyslipidemia and atherosclerosis, and for translational studies.
authors.affiliation: Department of Genetics, Southwest Foundation for Biomedical Research, San Antonio, 7620 NW Loop 410, TX 78227, USA.
authors.forename: Genesio M
authors.initials: GM
authors.lastname: Karere
authors.forename: Jeremy P
authors.initials: JP
authors.lastname: Glenn
authors.forename: John L
authors.initials: JL
authors.lastname: VandeBerg
authors.forename: Laura A
authors.initials: LA
authors.lastname: Cox
mesh_terms: D000818:Animals; D002318:Cardiovascular Diseases / Q000235:genetics; D055028:Comparative Genomic Hybridization; D017931:DNA Primers / Q000235:genetics; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000235:genetics*; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008214:Lymphocytes / Q000378:metabolism*; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D010215:Papio / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D035683:MicroRNAs