title: Haplotype distribution and evolutionary pattern of miR-17 and miR-124 families based on population analysis.
abstract: BACKGROUND
  MicroRNAs (miRNAs) are small, endogenously expressed non-coding RNAs that regulate mRNAs post-transcriptionally. Previous studies have explored miRNA evolutionary trend, but evolutionary history and pattern in the miRNA world are still not fully clear. In the paper, we intended to analyze miRNA haplotype distribution and evolutionary network by analyzing miRNA sequences of miR-17 and miR-124 families across animal species as special populations.
  
  
  RESULTS
  31 haplotypes were detected in miR-17 family while only 9 haplotypes were defined in miR-124 family. The complex miR-17 family was mainly distributed in vertebrates, but miR-124 was shared by more animal species from Caenorhabditis to Homo and had a wide distribution spectrum. Some haplotypes of the two miRNA families appeared discontinuous distributions across animals. Compared with a simple phylogenetic network in miR-124 family, miR-17 family indicated a complex network with some median vectors that might be lost ancestral or potential miRNA haplotypes. By analyzing different miRNAs across 12 animal species, we found these small RNAs showed different haplotype diversities, haplotype distributions and phylogenetic networks.
  
  
  CONCLUSIONS
  Different miRNAs had quite different haplotype distributions and evolutionary patterns. Discontinuous distributions of miRNAs and median vectors in phylogenetic networks implied more members in the miRNA world. miRNA may be an excellent phylogenetic marker to discover its evolutionary history and pattern across the animal kingdom.
authors: State Key Laboratory of Bioelectronics, School of Biological Science and Medical Engineering, Southeast University, Nanjing, China.
authors: Li
authors: L
authors: Guo
authors: Beili
authors: B
authors: Sun
authors: Fei
authors: F
authors: Sang
authors: Wei
authors: W
authors: Wang
authors: Zuhong
authors: Z
authors: Lu
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans; D016000:Cluster Analysis; D019143:Evolution, Molecular; D006239:Haplotypes; D006801:Humans; D035683:MicroRNAs / Q000235:genetics* / Q000378:metabolism; D008957:Models, Genetic; D010802:Phylogeny; D012984:Software; D013045:Species Specificity
chemical_list: C509207:MIRN124 microRNA, human; C524941:MIRN17 microRNA, human; D035683:MicroRNAs