1. Morpholino Oligos:
Making Sense of Antisense?
g
Based on the review of Janet Heasman
Division of Developmental Biology, Children’s Hospital Medical Center,
Cincinnati, Ohio
Developmental Biology 243, 209–214 (2002)
08.12.2008 Genie Genetique – Sebastian König and Sebastian Olényi
2. Overview
• Do nreg lating gene e pression helps
Downregulating expression
understanding their functions
• Most of the experiments are done to understand
embryonic development
• Morpholinos are synthetic, usually 25 bases long,
with a diff
ith different sugar-structure
t t t
• Typical model organisms: zebrafish, African clawed
frog,
frog sea urchin, chick and mice.
urchin mice
Genie Genetique – Sebastian König and
08.12.2008
Sebastian Olényi
3. Structures
Genie Genetique – Sebastian König and
08.12.2008
Sebastian Olényi
4. Principle
“DGI reliably
achieves >90%
knockdown of
gene expression”
Genie Genetique – Sebastian König and
08.12.2008
Sebastian Olényi
5. Advantages
• E
Equal or hi h efficacy and specificity
l higher ffi d ifi it
greatly superior to any other antisense
structural type
t t lt
• Morpholinos do not activate the complement
cascade or the interferon system and are not
degraded
• Excellent solubility and stability
• Working at high concentrations is p
g g possible
• No need for RNase H to ensure their activity
Genie Genetique – Sebastian König and
08.12.2008
Sebastian Olényi
6. Disadvantages
• Completely artificial molecule, so no
vectors possible
p
• Delivery usually only via microinjection or
electroporation
• Not always high effects, uncertain amount
of downregulation
• Side-effects for high dosage oligo-
dosage,
dependent
Genie Genetique – Sebastian König and
08.12.2008
Sebastian Olényi
7. Application
• 25
25mers, Little self-complementarity (l
Littl lf l t it (less th 4
than
contiguous intrastrand base pairs)
• Less than 36% guanine content
• No runs of more than triplets of GGG
• Concentrations between 1 and 12µM
• 2-4 days effectiveness
• Controls with
Co t o s t
– mRNA rescue experiments
– Two different morpholinos directed to different gene
parts with same effect
t ith ff t
– Other over- and/or underexpression studies
Genie Genetique – Sebastian König and
08.12.2008
Sebastian Olényi
9. Thank you!
References
http://www.sanger.ac.uk/Info/Press/gfx/zebrafish.jpg
http://www.columbia.edu/itc/cerc/danoff‐burg/invasion_bio/inv_spp_summ/xenopuslaevis.jpg
http://www.alaskaunderseatours.com/photos/Red‐Sea‐Urchin.jpg
http://www.gene‐tools.com/products_and_applications
http://www.bentham.org/ctmc/openaccessarticles/ctmc7‐7/0003R.pdf
Genie Genetique – Sebastian König and
08.12.2008
Sebastian Olényi
