Chicken ribosomal intergenic spacer deciphering

Ribosomal DNA (rDNA) repeats are situated in the nucleolus organizer regions (NORs) of chromosomes and transcribed into rRNA for ribosome biogenesis. They are therefore an essential component of eukaryotic genomes. rDNA repeat units consist of rRNA gene clusters transcribed in single pre-rRNA molecules, each separated by intergenic spacers (IGSs) containing regulatory elements for rRNA gene cluster transcription. Because of their high repeat content, rDNA sequences are usually absent from genome assemblies and our purpose here is to take advantage of long-read sequencing technology to describe the chicken IGSs, filling in the gap in the rDNA sequence of one of the key domesticated animals.