title: miR-34 is maternally inherited in Drosophila melanogaster and Danio rerio.
abstract: MicroRNAs (miRNAs) are small, endogenous, regulatory RNA molecules that can bind to partially complementary regions on target messenger RNAs and impede their expression or translation. We rationalized that miRNAs, being localized to the cytoplasm, will be maternally inherited during fertilization and may play a role in early development. Although Dicer is known to be essential for the transition from single-celled zygote to two-cell embryo, a direct role for miRNAs has not yet been demonstrated. We identified miRNAs with targets in zygotically expressed transcripts in Drosophila using a combination of transcriptome analysis and miRNA target prediction. We experimentally established that Drosophila miRNA dme-miR-34, the fly homologue of the cancer-related mammalian miRNA miR-34, involved in somatic-cell reprogramming and having critical role in early neuronal differentiation, is present in Drosophila embryos before initiation of zygotic transcription. We also show that the Drosophila miR-34 is dependent on maternal Dicer-1 for its expression in oocytes. Further, we show that miR-34 is also abundant in unfertilized oocytes of zebrafish. Its temporal expression profile during early development showed abundant expression in unfertilized oocytes that gradually decreased by 5 days post-fertilization (dpf). We find that knocking down the maternal, but not the zygotic, miR-34 led to developmental defects in the neuronal system during early embryonic development in zebrafish. Here, we report for the first time, the maternal inheritance of an miRNA involved in development of the neuronal system in a vertebrate model system.
authors.affiliation: CSIR-Institute of Genomics and Integrative Biology, Delhi 110 007, India, Ambedkar Centre for Biomedical Research, Delhi University, Delhi 110007, India.
authors.forename: Kartik
authors.initials: K
authors.lastname: Soni
authors.forename: Ashwani
authors.initials: A
authors.lastname: Choudhary
authors.forename: Ashok
authors.initials: A
authors.lastname: Patowary
authors.forename: Angom Ramcharan
authors.initials: AR
authors.lastname: Singh
authors.forename: Shipra
authors.initials: S
authors.lastname: Bhatia
authors.forename: Sridhar
authors.initials: S
authors.lastname: Sivasubbu
authors.forename: Shanti
authors.initials: S
authors.lastname: Chandrasekaran
authors.forename: Beena
authors.initials: B
authors.lastname: Pillai
mesh_terms: D000818:Animals; D001921:Brain / Q000196:embryology; D019295:Computational Biology; D029721:Drosophila Proteins / Q000378:metabolism* / Q000502:physiology; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D055785:Gene Knockdown Techniques; D040582:Inheritance Patterns; D035683:MicroRNAs / Q000032:analysis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D009474:Neurons / Q000378:metabolism; D009865:Oocytes / Q000737:chemistry; D020365:RNA Helicases / Q000502:physiology; D043244:Ribonuclease III / Q000502:physiology; D015027:Zebrafish / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D015053:Zygote / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; C570893:MIRN34 microRNA, Drosophila; C581930:MIRN34 microRNA, zebrafish; D035683:MicroRNAs; C515033:Dcr-1 protein, Drosophila; D043244:Ribonuclease III; D020365:RNA Helicases