Cloning and characterization of microRNAs from Brassica napus.
A library containing approximately 40,000 small RNA sequences was constructed for Brassica napus. Analysis of 3025 sequences obtained from this library resulted in the identification of 11 conserved miRNA families, which were validated by secondary structure prediction using surrounding sequences in the Brassica genome. Two 21 nt small RNA sequences reside within the arm of a pre-miRNA like stem-loop structure, making them likely candidates for novel non-conserved miRNAs in B. napus. Most of the conserved miRNAs were expressed at similar levels in a F1 hybrid B. napus line and its four double haploid progeny that showed marked variations in phenotypes, but many were differentially expressed between B. napus and Arabidopsis. The miR169 family was expressed at high levels in young leaves and stems, but was undetectable in roots and mature leaves, suggesting that miR169 expression is developmentally regulated in B. napus.
Biotechnology Research Institute/The National Key Facility for Crop Gene Resources and Genetic Improvement, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
Lei
L
Wang
Ming-Bo
MB
Wang
Jin-Xing
JX
Tu
Christopher A
CA
Helliwell
Peter M
PM
Waterhouse
Elizabeth S
ES
Dennis
Ting-Dong
TD
Fu
Yun-Liu
YL
Fan
D017360:Arabidopsis / Q000235:genetics; D001483:Base Sequence; D029688:Brassica napus / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018506:Gene Expression Regulation, Plant; D035683:MicroRNAs / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D009690:Nucleic Acid Conformation; D010802:Phylogeny; D018749:RNA, Plant / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D017423:Sequence Analysis, RNA / Q000379:methods
D035683:MicroRNAs; D018749:RNA, Plant