09-27 smc

Distribution of repetitive DNA elements within Exon / Intron structures

    The 14  exons [numbered dark-green units] for a single protein-coding gene constitute a very small portion of the total 50 Kbp region. The introns  [light-green areas] include a number of families of repetitive DNA sequences, shown separately in the exploded views below. These include short interspersed repeats (SINES, including Alu family sequences), long interspersed repeats (LINEs, including the L1 family), long tandem repeats (LTRs), and simple sequence repeats (SSRs), also known as VNTRs (Variable Number of Tandem Repeats) or micro- or minisatellites. Note that the SSRs occur as two- or four-base motifs that are repeated n times each.

Figure modified from ©2002 by Griffiths et al.; all text material ©2015 by Steven M. Carr