| We find that full function of the endogenous rDNA locus depends not merely on the presence of the rDNA cistrons but also on chromosomal context. |
| Almost all eukaryotes have multiple copies of their nuclear ribosomal RNA cistrons, arranged in a long tandem array. |
| The estimate was defined at the scale of cistrons so as to exclude the possibility of recombination. |
| Distribution of nucleotide differences between two randomly chosen cistrons in a finite population. |
