Identification and characterization of microRNAs in normal equine tissues by Next Generation Sequencing.
The role of microRNAs (miRNAs) as a post-transcriptional gene regulator has been elucidated in a broad range of organisms including domestic animals. Characterization of miRNAs in normal tissues is an important step to investigate the functions of miRNAs in various physiological and pathological conditions. Using Illumina Next Generation Sequencing (NGS) technology, we identified a total of 292 known and 329 novel miRNAs in normal horse tissues including skeletal muscle, colon and liver. Distinct sets of miRNAs were differentially expressed in a tissue-specific manner. The miRNA genes were distributed across all the chromosomes except chromosomes 29 and 31 in the horse reference genome. In some chromosomes, multiple miRNAs were clustered and considered to be polycistronic transcript. A base composition analysis showed that equine miRNAs had a higher frequency of A+U than G+C. Furthermore, U tended to be more frequent at the 5' end of miRNA sequences. This is the first experimental study that identifies and characterizes the global miRNA expression profile in normal horse tissues. The present study enriches the horse miRNA database and provides useful information for further research dissecting biological functions of miRNAs in horse.
Laboratory of Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
Myung-Chul
MC
Kim
Laboratory of Environmental Health, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
Seung-Woo
SW
Lee
Laboratory of Environmental Health, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea; Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
Doug-Young
DY
Ryu
Laboratory of Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
Feng-Ji
FJ
Cui
Theragen Bio Institute, Suwon-city, Gyeonggi-do, Republic of Korea.
Jong
J
Bhak
Laboratory of Clinical Pathology, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea; Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
Yongbaek
Y
Kim
D000818:Animals; D001482:Base Composition; D002874:Chromosome Mapping; D006736:Horses / Q000235:genetics*; D035683:MicroRNAs / Q000235:genetics*
D035683:MicroRNAs