Systematic identification and evolutionary features of rhesus monkey small nucleolar RNAs.
BACKGROUND
Recent studies have demonstrated that non-protein-coding RNAs (npcRNAs/ncRNAs) play important roles during eukaryotic development, species evolution, and in the etiology of disease. Rhesus macaques are the most widely used primate model in both biomedical research and primate evolutionary studies. However, most reports on these animals focus on the functional roles of protein-coding sequences, whereas very little is known about macaque ncRNAs.


RESULTS
In the present study, we performed the first systematic profiling of intermediate-size ncRNAs (50 to 500 nt) from the rhesus monkey by constructing a cDNA library. We identified 117 rhesus monkey ncRNAs, including 80 small nucleolar RNAs (snoRNAs), 29 other types of known RNAs (snRNAs, Y RNA, and others), and eight unclassified ncRNAs. Comparative genomic analysis and northern blot hybridizations demonstrated that some snoRNAs were lineage- or species-specific. Paralogous sequences were found for most rhesus monkey snoRNAs, the expression of which might be attributable to extensive duplication within the rhesus monkey genome. Further investigation of snoRNA flanking sequences showed that some rhesus monkey snoRNAs are retrogenes derived from L1-mediated integration. Finally, phylogenetic analysis demonstrated that birds and primates share some snoRNAs and host genes thereof, suggesting that both the relevant host genes and the snoRNAs contained therein may be inherited from a common ancestor. However, some rhesus monkey snoRNAs hosted by non-ribosome-related genes appeared after the evolutionary divergence between birds and mammals.


CONCLUSIONS
We provide the first experimentally-derived catalog of rhesus monkey ncRNAs and uncover some interesting genomic and evolutionary features. These findings provide important information for future functional characterization of snoRNAs during primate evolution.
Zhang
Yong
Y
National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, PR China.
Liu
Jun
J
Jia
Chunshi
C
Li
Tingting
T
Wu
Rimao
R
Wang
Jie
J
Chen
Ying
Y
Zou
Xiaoting
X
Chen
Runsheng
R
Wang
Xiu-Jie
XJ
Zhu
Dahai
D
D000818:Animals; D002645:Chickens; D055028:Comparative Genomic Hybridization; D019143:Evolution, Molecular; D020440:Gene Duplication; D015723:Gene Library; D023281:Genomics; D008253:Macaca mulatta / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D010802:Phylogeny; D020537:RNA, Small Nucleolar / Q000235:genetics*; D017423:Sequence Analysis, RNA
D020537:RNA, Small Nucleolar