RT Journal Article
SR Electronic
T1 Maternal- and somatic-type snoRNA expression and processing in zebrafish development
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 858936
DO 10.1101/858936
A1 Johanna  F.B. Pagano
A1 Mauro  D. Locati
A1 Wim  A Ensink
A1 Marina  van Olst
A1 Selina van Leeuwen
A1 Wim  C. De Leeuw
A1 Ulrike Nehrdich
A1 Herman  P Spaink
A1 Han Rauwerda
A1 Martijs  J. Jonker
A1 Rob  J. Dekker
A1 Timo  M Breit
YR 2020
UL http://biorxiv.org/content/early/2020/02/06/858936.abstract
AB Small nucleolar RNAs (snoRNAs) are non-coding RNAs that play an important role in the complex maturation process of ribosomal RNAs (rRNAs). SnoRNAs are categorized in classes, with each class member having several variants present in a genome. Similar to our finding of specific rRNA expression types in zebrafish embryogenesis, we discovered preferential maternal- and somatic-expression for snoRNAs. Most snoRNAs and their variants have higher expression levels in somatic tissues than in eggs, yet we identified three snoRNAs; U3, U8 and snoZ30 of which specific variants show maternal- or somatic-type expression. For U3 and U8 we also found small-derived snoRNAs that lack their 5’ rRNA recognition part and are essentially Domain II hairpin structures (U-DII). These U-DII snoRNAs from variants showed similar preferential expression, in which maternal-type variants are prominently expressed in eggs and subsequently replaced by a somatic-type variants during embryogenesis. This differential expression is related to the organization in tandem repeats (maternal type) or solitary (somatic-type) genes of the involved U snoRNA loci. The collective data showed convincingly that the preferential expression of snoRNAs is achieved by transcription regulation, as well as through RNA processing. Finally, we observed small-RNAs derived from internal transcribed spacers (ITSs) of a U3 snoRNA loci that via complementarity binding, may be involved in the biosynthesis of U3-DII snoRNAs. Altogether, the here described maternal- and somatic-type snoRNAs are the latest addition to the developing story about the dual ribosome system in zebrafish development.