Spacers were the fictional first humans to emigrate to space in Isaac Asimov's Foundation and related Robot and Empire series. In these stories, about a millennium thereafter, they severed political ties with Earth, and embraced low population-growth and extreme longevity (with lifespans reaching 400 years) as a means for a high standard of living, in combination with using large numbers of robots as servants.

Why nuclear ribosomal DNA spacers (ITS) tell different stories in Quercus.
Holding chambers (spacers) versus nebulisers for beta-agonist treatment of acute asthma.
Solid supporrt with oligonucleotides, spacers, linking groups and double strands
Making a better RNAi vector for Drosophila: use of intron spacers.
Ribosomal External and Internal Transcribed Spacers: Combined Use in the Phylogenetic Analysis of Medicago (Leguminosae)
Phylogenetic utility of the internal transcribed spacers of nuclear ribosomal DNA in plants: an example from the compositae.
The CRISPRdb database and tools to display CRISPRs and to generate dictionaries of spacers and repeats
Phylogenetic analysis of Sorghum and related taxa using internal transcribed spacers of nuclear ribosomal DNA.
Identification of yeasts by RFLP analysis of the 5.8S rRNA gene and the two ribosomal internal transcribed spacers.
Discrimination of Streptomyces albidoflavus strains based on the size and number of 16S-23S ribosomal DNA intergenic spacers.