title: Comparative transcriptome analysis reveals a regulatory network of microRNA-29b during mouse early embryonic development.
abstract: MicroRNAs are endogenous ~22 nt RNAs that regulate gene expression by translational inhibition and mRNA destabilization. MicroRNA-29b (miR-29b) is essential for progression of mouse embryos past preimplantation development; however, details of the underlying regulatory network remain to be elucidated. Here, we used RNA sequencing to identify changes in the transcriptome of mouse embryos in response to miR-29b inhibition. Morula-stage embryos that had been subject to miR-29b inhibition throughout preimplantation development exhibited significant expression changes in 870 genes compared with controls. Among 405 genes that were downregulated, 30 genes encoded factors with known essential function during early embryonic development, including the pluripotent stem cell factor Nanog. We identified 19 genes encoding putative miR-29b target transcripts. These included Zbtb40, Hbp1, Ccdc117, Ypel2, Klf4, and Tmed9, which are upregulated at the 4-cell state of mouse development concomitant with miR-29b downregulation. Luciferase reporter analysis confirmed that Zbtb40, Hbp1, Ccdc117, Ypel2, and Klf4 transcripts are direct targets of miR-29b. These results suggest that miR-29b decreases the mRNA levels of several target genes during early mouse development, including the gene encoding the reprogramming factor Klf4. We hypothesize that inhibition of miR-29b causes overexpression of its target genes, triggering downstream signaling networks to decrease the expression of genes that are essential for embryonic development. In conclusion, miR-29b controls an extensive regulatory network in early mouse embryos, which comprises reprogramming factors and molecular regulators of post-transcriptional modification processes.
authors.affiliation: Department of Reproduction, Nanjing Maternity and Child Health Care Hospital, Affiliated to Nanjing Medical University, Nanjing 210004, P.R. China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, P.R. China.
authors.forename: Tao
authors.initials: T
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, P.R. China.
authors.forename: Jinyuan
authors.initials: J
authors.lastname: Wan
authors.affiliation: Department of Reproduction, Nanjing Maternity and Child Health Care Hospital, Affiliated to Nanjing Medical University, Nanjing 210004, P.R. China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Reproduction, Nanjing Maternity and Child Health Care Hospital, Affiliated to Nanjing Medical University, Nanjing 210004, P.R. China.
authors.forename: Xiaojiao
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Reproduction, Nanjing Maternity and Child Health Care Hospital, Affiliated to Nanjing Medical University, Nanjing 210004, P.R. China.
authors.forename: Jiayi
authors.initials: J
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, P.R. China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Nanjing Medical University, Nanjing 210029, P.R. China.
authors.forename: Mingxi
authors.initials: M
authors.lastname: Liu
authors.affiliation: Department of Reproduction, Nanjing Maternity and Child Health Care Hospital, Affiliated to Nanjing Medical University, Nanjing 210004, P.R. China.
authors.forename: Xiufeng
authors.initials: X
authors.lastname: Ling
authors.affiliation: Department of Reproduction, Nanjing Maternity and Child Health Care Hospital, Affiliated to Nanjing Medical University, Nanjing 210004, P.R. China.
authors.forename: Junqiang
authors.initials: J
authors.lastname: Zhang
mesh_terms: D000818:Animals; D047108:Embryonic Development / Q000235:genetics*; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D053263:Gene Regulatory Networks / Q000235:genetics*; D000090062:Kruppel-Like Factor 4; D051379:Mice / Q000196:embryology* / Q000235:genetics; D035683:MicroRNAs / Q000235:genetics*; D011247:Pregnancy
chemical_list: C000715467:KLF4 protein, human; C000715468:Klf4 protein, mouse; D000090062:Kruppel-Like Factor 4; C532045:MIRN29a microRNA, human; D035683:MicroRNAs
keywords: Klf4; Nanog; embryogenesis; miR-29b; reprogramming