Page 115 - 80_02

The
role
of
the
catecholaminergic…

Figure
3.
The
chick
and
the
human
embryos
at
early
stages
of
cardiogenesis.
The
chick

embryo
reaches
the
stage
15
([16])
at
~2.5
days
of
incubation.
The
heart
tube
is
already
turned
and

specified
in
auricular
and
ventricular
regions.
The
human
embryo
reaches
the
stage
12
(Carnigie

classification,
http://php.med.unsw.edu.au/embryology/index.php?title=Carnegie_Stages)
at
26-­-30

days
of
pregnancy.
The
heart
prominence
is
indicated
by
the
arrow.
Note
the
great
similarity
of

both
embryos
at
these
stages.

The
chimeric
transcripts
containing
exons
from
th
and
ins
genes
give
rise
to

two
novel
isoforms
of
the
TH
protein
(TH-­-INS1
and
2)
with
markedly
reduced

functionality,
when
compared
to
the
canonical
TH.
The
levels
of
L-­-DOPA
in
cells

expressing
TH-­-INS1
are
approximately
5-­-fold
lower
than
those
found
in
cells

expressing
similar
or
lower
amounts
of
TH
protein
(Figure
2).

In
addition,
the
TH-­-

351