BIO 4120 Lab SEC 009
January 25, 2018
Regeneration of Tissue and Skin in African Spiny Mice
How do African Spiny Mice
regenerate their skin and tissue?
Skin shedding and tissue
regeneration in African spiny mice (Acomys)
The purpose of this paper is to show the
first mammal to be able to demonstrate autotomy in mammals and can regenerate
the tissue lost (Seifert, 2012).
Their approach was to trap two types of
Acomys, A. kempi and A. percivali, and having them go through vigorous movement
and watching the result of the movement.
They also tested the tensile strength
between the skin of Acomys compared to Mus.
They tested cellular features of Acomys
and found that it was comparable to other mice, but did not find a fracture
plane which is what some reptiles use for skin autonomy.
The vigorous movement of Acomys caused
their skin to tear easily and leads to autotomy causing them to lose most of
their tissue and skin.
This led the scientists to test the
tensile strength of Acomys skin and compare it to Mus. It was found that Mus
skin has skin 20 times stronger than Acomys and that it required 77x more
energy to break Mus skin compared to Acomys. This result led to the scientists
believing that skin tearing easily in response to low tension shows a
mechanical basis for the reason of their skin weakness.
The results showed how Acomys can
demonstrate Autotomy and regenerate their tissue lost. This study shows how
mammals may have the ability to have higher capacity of regeneration. Acomys
can be a good organism to promote research in regeneration in tissue of
article testing for skin autotomy and tissue regeneration in African spiny mice
was a great article in showing how a mammal can have reptile like features and
regenerate tissue (Seifert, 2012). They tested for the strength of the skin,
connective tissue, and looked at different cells of Acomys during the
experiment (Seifert, 2012). But they did not answer the question of what genes are
expressed during regeneration of Acomys. The next article tests the difference
of gene expression when skin is regenerated in Mus and Acomys.
How is the gene expression
of tissue and skin regeneration different in Acomys and Mus?
A Comparative Analysis of
Gene expression profiles during Skin regeneration in Mus and Acomys
To understand the difference of gene
expression of Acomys that show scar-free healing to Mus scarring.
The researchers put 8mm wounds and looked
at gene expression at days 3, 5, 7, and 14 of both Acomys and Mus. They extracted
RNA and generated cDNA. The researchers then processed the RNA for microarray
genes up and 1 gene downregulated at day 3
genes up and 3 genes downregulated at day 5
genes up and 1 gene downregulated at day 3
genes up and 2 genes downregulated at day 5
For both mus results the up genes are
involved in inflammatory pathway and neutrophil and macrophage activation and
For both Acomys results the up genes were
shown to be involved in tissue remodeling and extracellular degradation and
The results show the difference between
how Acomys and mus react to wounds on a genetic level. The results also show an
understanding of how Acomys can produce scar free healing. This research progresses
in trying to figure out how humans can have scar-free healing.
This article showed how the gene of Acomys react to
wounds compared to other types of Mus. This is important in progressing the
research and trying to figure out how humans might be able to regenerate tissue
scar-free (Brant, 2015). But it does not really explain how important immune
system affects the tissue regeneration in Acomys. This next article explains
how macrophages are important during tissue regeneration.
How is the immune system affected
during tissue regeneration of Acomys?
Macrophages are necessary
for epimorphic regeneration in African spiny mice
To figure out how the immune system is
affects tissue regeneration.
Used African spiny mouse and examined
The researchers tested their hypothesis
that macrophages are important during tissue regeneration.
did this by looking at the differences between ear injuries of Acomys and Mus.
During injury, the researchers depleted
macrophages and expected the regeneration of Acomys to fail.
The researchers found that both species
have an acute inflammatory response, but the scarring of Mus showed a stronger
The difference in Acomys was that ROS had
a higher production rate and showed more persistence.
They also found that when in absence of
macrophages, during regeneration pro-inflammatory macrophages failed to enter
the regeneration blastemal.
The researchers concluded that their
results showed how important inflammatory cells are to tissue regeneration in
Seifert, A. W., Kiama, S. G.,
Seifert, M. G., Goheen, J. R., Palmer, T. M., & Maden, M. (2012). Skin
shedding and tissue regeneration in African spiny mice (Acomys). Nature,
489(7417), 561-+. doi:10.1038/nature11499
Brant, J. O., Lopez, M. C.,
Baker, H. V., Barbazuk, W. B., & Maden, M. (2015). A Comparative Analysis
of Gene Expression Profiles during Skin Regeneration in Mus and Acomys. Plos
One, 10(11). doi:10.1371/journal.pone.0142931
Simkin, J., Gawriluk, T. R.,
Gensel, J. C., & Seifert, A. W. (2017). Macrophages are necessary for
epimorphic regeneration in African spiny mice. Elife, 6.