title: Dynamic evolution and biogenesis of small RNAs during sex reversal.
abstract: Understanding origin, evolution and functions of small RNA (sRNA) genes has been a great challenge in the past decade. Molecular mechanisms underlying sexual reversal in vertebrates, particularly sRNAs involved in this process, are largely unknown. By deep-sequencing of small RNA transcriptomes in combination with genomic analysis, we identified a large amount of piRNAs and miRNAs including over 1,000 novel miRNAs, which were differentially expressed during gonad reversal from ovary to testis via ovotesis. Biogenesis and expressions of miRNAs were dynamically changed during the reversal. Notably, phylogenetic analysis revealed dynamic expansions of miRNAs in vertebrates and an evolutionary trajectory of conserved miR-17-92 cluster in the Eukarya. We showed that the miR-17-92 cluster in vertebrates was generated through multiple duplications from ancestor miR-92 in invertebrates Tetranychus urticae and Daphnia pulex from the Chelicerata around 580 Mya. Moreover, we identified the sexual regulator Dmrt1 as a direct target of the members miR-19a and -19b in the cluster. These data suggested dynamic biogenesis and expressions of small RNAs during sex reversal and revealed multiple expansions and evolutionary trajectory of miRNAs from invertebrates to vertebrates, which implicate small RNAs in sexual reversal and provide new insight into evolutionary and molecular mechanisms underlying sexual reversal.
authors.affiliation: Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, P. R. China.
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, P. R. China.
authors.forename: Majing
authors.initials: M
authors.lastname: Luo
authors.affiliation: Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, P. R. China.
authors.forename: Yue
authors.initials: Y
authors.lastname: Sheng
authors.affiliation: Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, P. R. China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Hong
authors.affiliation: Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, P. R. China.
authors.forename: Hanhua
authors.initials: H
authors.lastname: Cheng
authors.affiliation: Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, P. R. China.
authors.forename: Rongjia
authors.identifier: 0000000297018009
authors.initials: R
authors.lastname: Zhou
mesh_terms: D000818:Animals; D005075:Biological Evolution; D019143:Evolution, Molecular; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D006066:Gonads / Q000502:physiology*; D034741:RNA, Small Interfering / Q000235:genetics*; D019849:Sex Determination Processes / Q000235:genetics*; D012733:Sex Differentiation / Q000235:genetics*
chemical_list: D034741:RNA, Small Interfering