With no explanation, label each line with "O", "other-biologything", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
``
Nodal
``
was
first
described
in
the
chick
embryo
,
where
genes
``
activin
receptor
IIa
,
Sonic
hedgehog
(
Shh
)
,
''
and
``
chick
nodal-related
1
(
cNR-1
)
''
were
found
to
be
asymmetrically
expressed
across
Hensen
’
s
node
with
``
cnR-1
``
expressed
on
the
left
side
.
``:O
Nodal:other-biologything
``:O
was:O
first:O
described:O
in:O
the:O
chick:O
embryo:O
,:O
where:O
genes:O
``:O
activin:other-biologything
receptor:other-biologything
IIa:other-biologything
,:O
Sonic:other-biologything
hedgehog:other-biologything
(:O
Shh:other-biologything
):O
,:O
'':O
and:O
``:O
chick:other-biologything
nodal-related:other-biologything
1:other-biologything
(:O
cNR-1:other-biologything
):O
'':O
were:O
found:O
to:O
be:O
asymmetrically:O
expressed:O
across:O
Hensen:O
’:O
s:O
node:O
with:O
``:O
cnR-1:other-biologything
``:O
expressed:O
on:O
the:O
left:O
side:O
.:O