DNA, Ribosomal Spacer

**Definition:** The intergenic DNA segments that are between the ribosomal RNA genes (internal transcribed spacers) and between the tandemly repeated units of rDNA (external transcribed spacers and nontranscribed spacers).

**Tree numbers:** - D13.444.308.324.230 - D13.444.308.475.230

**Synonyms:** - Ribosomal Spacer DNA