Intron /
Exon
Structure of a eukaryotic gene
The mRNA
message
for ovalbumin was hybridized
with
the the ssDNA template strand from
which it was transcribed. Instead of a one-to-one colinear
pairing as expected, the ssDNA "loops
out" in
order to pair with the mRNA.
This
indicates that the structure of the gene is a series of exons (1
- 7, above) that are expressed
in the mRNA, separated by a series of intervening
introns
(A - G)
that have been "spliced out" of the hnRNA.
The mature mRNA is 1872bp long: introns
make
up >75% of the length of the gene.
Figure © 2000 by
Griffiths et al. ; text © 2008 by Steven M. Carr