Progress in long non-coding RNAs in animals.

Long non-coding RNAs (lncRNAs) are important transcripts that are more than 200 nucleotides in length, and distribute extensively in animal and plant genomes. Accumulated studies demonstrate that lncRNAs play critical roles in biological processes related to embryogenesis, muscle development, lipid deposition and immune responses. They assist protein complexes in translocating to appropriate locations and participate in regulating gene activation and inactivation. Recently, rapid progress of lncRNA research is emerging, largely due to molecular biological technologies and information developed in the human genome project and the Encyclopedia of DNA Elements (ENCODE) project. For example, a dwarf open reading frame (DWORF) encoded by an annotated lncRNA was reported to activate the SERCA pump. Moreover, small regulatory polypeptide of amino acid response (SPAR) encoded by lncRNA LINC00961 was found to regulate muscle regeneration. These new results have revealed a novel model that lncRNA regulates biological processes using its small peptide product. In this review, we summarize the characteristics, databases, biological functions and molecular regulatory models, as well as research interests of lncRNAs in the future.