In contrast to the catalytic subunit of telomerase, its RNA subunit (TR) is highly divergent in size, sequence and biogenesis pathways across eukaryotes. Current views on TR evolution assume a common origin of TRs transcribed with RNA polymerase II in Opisthokonta (the supergroup including Animalia and Fungi) and Trypanosomida on one hand, and TRs transcribed with RNA polymerase III under the control of type 3 promoter, found in TSAR and Archaeplastida supergroups (including e.g. ciliates and Viridiplantae taxa, respectively). Here, we focus on unknown TRs in one of the largest Animalia order - Hymenoptera (Arthropoda) with more than 300 available representative genomes. Using a combination of bioinformatic and experimental approaches, we identify their TRs. In contrast to the presumed type of TRs (H/ACA box snoRNAs transcribed with RNA Polymerase II) corresponding to their phylogenetic position, we find here short TRs of the snRNA type, likely transcribed with RNA polymerase III under the control of the type 3 promoter. The newly described insect TRs thus question the hitherto assumed monophyletic origin of TRs across Animalia and point to an evolutionary switch in TR type and biogenesis that was associated with the divergence of Arthropods.

Agricultural Research Ltd Troubsko CZ 664 41 Czech Republic

Biology Centre of the Czech Academy of Sciences Institute of Entomology České Budějovice CZ 37005 Czech Republic

Department of Cell Biology and Radiobiology Institute of Biophysics of the Czech Academy of Sciences Brno CZ 61265 Czech Republic

Laboratory of Functional Genomics and Proteomics NCBR Faculty of Science Masaryk University Brno CZ 61137 Czech Republic

Mendel Centre for Plant Genomics and Proteomics CEITEC Masaryk University Brno CZ 62500 Czech Republic

The Boyce Thompson Institute Cornell University 533 Tower Road Ithaca NY 14850 USA

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