title: A discovery of novel microRNAs in the silkworm (Bombyx mori) genome.
abstract: MicroRNAs (miRNAs) are pivotal regulators involved in various physiological and pathological processes via their post-transcriptional regulation of gene expressions. We sequenced 14 libraries of small RNAs constructed from samples spanning the life cycle of silkworms, and discovered 50 novel miRNAs previously not known in animals and verified 43 of them using stem-loop RT-PCR. Our genome-wide analyses of 27 species-specific miRNAs suggest they arise from transposable elements, protein-coding genes duplication/transposition and random foldback sequences; which is consistent with the idea that novel animal miRNAs may evolve from incomplete self-complementary transcripts and become fixed in the process of co-adaptation with their targets. Computational prediction suggests that the silkworm-specific miRNAs may have a preference of regulating genes that are related to life-cycle-associated traits, and these genes can serve as potential targets for subsequent studies of the modulating networks in the development of Bombyx mori.
authors.affiliation: Key Laboratory of Genome Information and Sciences, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, 100029, China.
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Yu
authors.forename: Qing
authors.initials: Q
authors.lastname: Zhou
authors.forename: Yimei
authors.initials: Y
authors.lastname: Cai
authors.forename: Qibin
authors.initials: Q
authors.lastname: Luo
authors.forename: Hongbin
authors.initials: H
authors.lastname: Lin
authors.forename: Songnian
authors.initials: S
authors.lastname: Hu
authors.forename: Jun
authors.initials: J
authors.lastname: Yu
mesh_terms: D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000235:genetics* / Q000254:growth & development; D017124:Conserved Sequence; D018507:Gene Expression Regulation, Developmental; D053263:Gene Regulatory Networks; D019476:Insect Proteins / Q000096:biosynthesis / Q000235:genetics; D008018:Life Cycle Stages; D035683:MicroRNAs / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity
chemical_list: D019476:Insect Proteins; D035683:MicroRNAs