A novel Drosophila antisense scaRNA with a predicted guide function.
A significant portion of eukaryotic small ncRNA transcriptome is composed by small nucleolar RNAs. From archaeal to mammalian cells, these molecules act as guides in the site-specific pseudouridylation or methylation of target RNAs. We used a bioinformatics search program to detect Drosophila putative orthologues of U79, one out of ten snoRNAs produced by GAS5, a human ncRNA involved in apoptosis, susceptibility to cancer and autoimmune diseases. This search led to the definition of a list of U79-related fly snoRNAs whose genomic organization, evolution and expression strategy are discussed here. We report that an intriguing novel specimen, named Dm46E3, is transcribed as a longer, unspliced precursor from the reverse strand of eiger, a fly regulatory gene that plays a key role in cell differentiation, apoptosis and immune response. Expression of Dm46E3 was found significantly up-regulated in a mutant strain in which eiger transcription is greatly reduced, suggesting that these two sense-antisense genes may be mutually regulated. Relevant to its function, Dm46E3 concentrated specifically in the Cajal bodies, followed a dynamic spatial expression profile during embryogenesis and displayed a degenerate antisense element that enables it to target U1b, a developmentally regulated isoform of the U1 spliceosomal snRNA that is particularly abundant in embryos.
Tortoriello
Giuseppe
G
Department of Structural and Functional Biology, University of Naples Federico II, Complesso Universitario Monte Santangelo, Napoli, Italy.
Accardo
Maria Carmela
MC
Scialò
Filippo
F
Angrisani
Alberto
A
Turano
Mimmo
M
Furia
Maria
M
D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002460:Cell Line; D002874:Chromosome Mapping; D019295:Computational Biology / Q000379:methods; D029721:Drosophila Proteins / Q000235:genetics*; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology / Q000235:genetics*; D004625:Embryo, Nonmammalian / Q000196:embryology / Q000378:metabolism; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D017404:In Situ Hybridization, Fluorescence; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D009154:Mutation; D016372:RNA, Antisense / Q000235:genetics* / Q000502:physiology; D020537:RNA, Small Nucleolar / Q000235:genetics* / Q000502:physiology; D022661:RNA, Untranslated / Q000235:genetics / Q000502:physiology; D020133:Reverse Transcriptase Polymerase Chain Reaction
D029721:Drosophila Proteins; D008565:Membrane Proteins; D016372:RNA, Antisense; D020537:RNA, Small Nucleolar; D022661:RNA, Untranslated; C464573:egr protein, Drosophila