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Journal of Biomedicine and Biotechnology
Volume 2012, Article ID 679563, 8 pages
Research Article

Genome-Wide Analysis of mir-548 Gene Family Reveals Evolutionary and Functional Implications

1Jiangsu Key Laboratory for Molecular and Medical Biotechnology, College of Life Science, Nanjing Normal University, Nanjing 210046, China
2Department of Epidemiology and Biostatistics and Ministry of Education Key Lab for Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing 210029, China

Received 16 May 2012; Accepted 25 July 2012

Academic Editor: Mouldy Sioud

Copyright © 2012 Tingming Liang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


mir-548 is a larger, poorly conserved primate-specific miRNA gene family. 69 human mir-548 genes located in almost all human chromosomes whose widespread distribution pattern implicates the evolutionary origin from transposable elements. Higher level of nucleotide divergence was detected between these human miRNA genes, which mainly derived from divergence of multicopy pre-miRNAs and homologous miRNA genes. Products of  mir-548, miR-548-5p, and miR-548-3p showed inconsistent evolutionary patterns, which partly contributed to larger genetic distances between pre-miRNAs. “Seed shifting” events could be detected among miR-548 sequences due to various 5′ ends. The events led to shift of seed sequences and target mRNAs, even generated to new target mRNAs. Additionally, the phenomenon of miRNA:miRNA interaction in the miRNA gene family was found. The potential interaction between miRNAs may be contributed to dynamic miRNA expression profiles by complementarily binding events to form miRNA:miRNA duplex with 5′-/3′-overhangs. The miRNA gene family had important roles in multiple biological processes, including signaling pathways and some cancers. The potential abundant roles and functional implication further led to the larger and poorly conserved gene family with genetic variation based on transposable elements. The evolutionary pattern of the primate-specific gene family might contribute to dynamic expression profiles and regulatory network.