mutagen-methylcholanthrene. (Hollander and. Strong. 1951). The tail ofthis mouse was about. â two-thirds normal length, and the distal end showed a peculiar.
GENETICALLY CONTROLLED NUCLEUS PULPOSUS R. J. Franz
the
Medical
BERRY,
Research
DEGENERATION IN THE MOUSE
LONDON,
council
I n the a fairly
few years
radical
the
in
past
change,
production
As long
ago
disc
protrusion
other
levers
as
1948
to the
conclusion
normal
ageing
form
discs
predisposing
changes.
However,
If
why
Lance!
1958).
desiccation
This
discs
remain
fact
must
and
trauma
in the
is
discs
unexplained
may
in
major
unless
it can
“normal” changes during life. However, just such changes Hansen (1951, 1952) showed that breeds
the
of dogs,
nucleus
and
that
pulposus.
determined
effect
prolapse
The in the
a cephalo-caudad
111
in these
purpose
house
direction THE
the
The
work
described
pBr
strain
which
in
two-thirds
tip.”
The
a partial
are
fertile.
name
been
length,
and
mice
Pintail
shown
the
tail
kinks maintain
conclusion
is strengthened
two
at which
weeks,
THE The
VOL.
43B,
gene
of the NO.
have are
2,
MAY
the the
due
THE
certain
changes
Strong
1951).
showed
a peculiar
was
notochord
found
in a mouse
The
alleged
tail
ofthis
thin
and
to this trait. The and homozygous any
in
genetically
of the
carcinogen-and
and
hardly
animals. in different
a similar
reduction
end
(Pt/+)
people
it is found possible the first twenty or discs undergo only
to degenerative
which
powerful
given
to
MOUSE
a mutation
the
have
the
has
1961
or
occurred
an
more
incidental
tail
the
observation
leave
on but
in
no tail
of
their
nest
GENE the which
the
and
mouse
was
often
about
distorted
normally for
behaves the gene
debilitated:
they
(Pt/Pt)
are
of
mouse
somewhat
gene
intervertebral is only
part
The
of
kinks
run
only
around
THE
to appear
discs
tail
at
(Fig.
2),
explanation
discs one
which
are
another. about
This the
age
of
actively.
INTERVERTEBRAL
revealed
the
probable
intervertebral relationship
tail
and ON
distal
kinking.
abnormal
correct that
the
PINTAIL
effect
animals,
kinks
with
result in
mice
OF THE
living
one
have vertebrae by
time
EFFECT
Pintail
examination
mice
heterozygotes
to
distal
IN
to
with
that
unless during whose
difficult
(Annotation,
abnormalities.
usually
insufficient
is
Pintail
intestinal
Pintail
refers
treated
is “
is to describe a progressive
MUTATION
paper
the
is certainly from
(symbol Pt) was mice heterozygous
“
and
Homozygous
have
but several that
Pintail
“
dominant,
frequently
1960).
(Hollander
normal
as
resulting
(Berry
it
to
associated
in at least two experimental rates of disc prolapse exist
communication
mouse,
this
had
animals
of this
PINTAIL
mutagen-methylcholanthrene “
have been shown markedly different
is rarely
prolapse
be
to point
as similar
disc derangements
an inherent proneness to disc lesions, or, in other words, to divide the population into those whose discs show such changes thirty years of life that they are predisposed to prolapse, and those
to by
biophysical seem
regarded
people
have
1958).
predispose increased
1958)
be
their
factor
Lance!
and
Naylor
undergone
a large
which possibly
Histochemical 1958,
factor
free from
is not
defects nature,
in older
a major
have
(Annotation,
“
Hendry
degeneration
relatively
remain
that absent
pregnancy.”
1957,
gross
“
be
there are anatomical of a developmental
weaknesses in
the elderly
often
Malinsk’
Unit,
disc protrusion
conceded
may
toxaemia
1952,
that
prolapse.
understand
of trauma,
(Charnley
Research
of intervertebral
that likely
“
Ge,zetics
London
generally
and
suggested are most
which
in the
ofthe
prolapse,
Jackson
and
it is now
“
disc
College,
on the etiology
and
of
studies
with
ideas
THE
ENGLAND
Experimental
Unil’ersity
OF
which by
DISCS
is not
histological
obvious
from
an
techniques.
387
388
R. J. BERRY
One observed
ofthese that
preparations skeleton
techniques the
must
mucoid
(Noback of a number
be described.
nucleus
pulposus
1916,
Griineberg
of normal
and
GrUneberg is stained
1953). abnormal
(1958)
in a personal
clearly
in methylene
very
This
observation aged
animals
was
three
-:---
FIRST THORACIC VERTEBRA
weeks
and
clearance
and older
the was
axial
stained
NORMAL
--
FIR5T-.
__
LUMBAR VERTEBRA
-
::
blue
utilised
Pv+
Pt/+
I
communication
2
FIG. .
I-Freehand
Figure
lene of
blue the
and
vertebral
old
column
to show shape
Figure
with
nucleus
methylene
preparations
tied blue,
are
those
pulposus. to
a glass
dehydrated of
variation
Pt
-L
(left)
at twenty-five in size
and
pulposi.
drawings
of the distal
of the as those
tails of mice from the illustrated in Figure 1. from Genetical Research, 1, 1960.)
I
FIG.
and
the
2-Freehand
(Reproduced
the
mates
of methypreparations
of
litter
the nuclei
of
two-thirds same litter
straightened
clearance
± 7+ (right)
days
to show
drawings
stained
animals
The
animals
plate,
and
with aged
were fixed
killed
and
in formol
the
vertebral
saline.
The
alcohol
and
cleared
in
about
three
weeks.
Soon
THE
JOURNAL
column
specimens
methyl
salicylate.
afterwards OF
removed, were
BONE
the AND
stained The
best
affinity
JOINT
SURGERY
of
GENETICALLY
the
nuclei
pulposi
property or
There
are and
changes
caudad
the
normal
mouse
; in
in the
size
the
Pintail
in
staining
increase
boundary
in the
region
lower
lumbar
they
size of
are
PULPOSUS
diminishes. of the genotypes
age,
stain
and
staining
intensity
pulposi
in the
the
nucleus
more
or
pulposus less
THE
by
hardly
of
the
more
intense
as
is accompanied
by
particularly
age
nuclei
of eight
pulposi
region
progressively the
in staining
the
at all.
cervical
stained
389
MOUSE
decrease but
evenly
becomes
pulposus,
IN
This
same
nuclei
staining
nucleus
fashion
completely
of both
The
NUCLEUS
stain
region
intensity
of each
not
the
THE
in normals
size
mice the nuclei thoracic region
lumbar
are
for
2).
the
OF
than
the
in the
in a characteristic
caudad
both
More
normal and Pintail projection, in the and
in
1 and
This
staining
cervical
(Figs.
column
size.
the
in the
differences
pulposi
vertebral
region
in Pintails
Pintails
normal.
nuclei
discs
DEGENERATION
trunk
quicker
the
so
normals
in
in the
is rather
weeks
less
CONTROLLED
are
in
more
or
decreases. whole the
discs
a decrease
in the
in the
and
tail,
The
way
down
are
the
reduced
definition
the
of
shape
also
from head to tail. Between the cervical vertebrae in both pulposi are roughly cigar shaped as seen in a thoraco-ventral those of Pintails are more spherical than those of normals,
are
flatter
regular.
The
region.
There
and
thinner-but
nuclei are
the
pulposi
no
nuclei
outlines
in normal pulposi
of some mice
between
of those
reach the
their
first
more greatest
three
sacral
vertebrae. MEASUREMENT
In an the
attempt
nucleus
to make the in clearance
pulposus
OF
THE
above observations preparations were
NUCLEI
PULPOSI
quantitative, measured
the under
two main a microscope
diameters fitted
of with
-#{247}/+ Pt/+ Pt/Pt
---
INTERVERTEBRAL Variation in size ofthe nucleus pulposus of the two main diameters in arbitrary three Pt L (broken line) and
a Leitz micrometer the whole of the in
upon VOL.
the
last
43 B,
NO.
tail of
2,
discs litters
MAY
1961
made containing
NUMBER
FIG. 3 along the vertebral column. The vertical ordinate is the units. Mean values of a litter of two ± ‘-i(continuous one PtPt (dotted line) animals aged twenty-one days.
screw objective. length of the vertebral
few
a series
DISC
product line),
it was possible to measure these dimensions for almost column, although the diffuse boundary of the staining
accurate normal,
measurement Pt/±,
difficult.
and
Pt/Pt
Measurements animals.
All
were three
made
genotypes
390
R. J. BERRY
had
a fairly
lot of both
constant inter-
characterise
pattern
and
each
of size
intra-litter
nucleus
variation
variation.
pulposus.
FIG.
along
The The
the
product
sizes
of
column,
although
there
of the two
diameters
was
the
nuclei
pulposi
5
in
the
quite
a
best
to
genotypes
6
FIG.
4 TO 6 through lumbar intervertebral (Fig. 4), pt(Fig. 5) and PIP!
all
was found
FIGS.
Photomicrographs chlorantine
were
of
the
fast
same
showed
a marked
pulposi
in the
in
size
along
of sagittal lOj red of newborn
order
posterior the
in the
reduction vertebral
sections -
cervical
region
; from
in
in
Pintail
thoracic column
size; and
the
lumbar can
about
tenth
homozygote
regions.
be clearly
the The
seen
in
discs (Fig.
stained 6) litter
disc there
Figure THE
caudad, were
progressive
with alcian mates. (
nature
the
blue I 15.)
and
#{149}
abnormals
virtually
no
of the
nuclei
reduction
3.
JOURNAL
OF
BONE
AND
JOINT
SURGERY
GENETICALLY
CONTROLLED
DEGENERATION
OF
THE
HISTOLOGICAL
The
consequences
histologically.
in preference acid, The
sections
fast
red
by were
(Lison
and
The
material
Peterfi’s
stained
(Figs.
with
size the
was fixed
of
the
nuclei
lumbo-sacral
cell
of
wall
(stained
with
alcian
process
seemed
to
fluid,
serially
decalcified
sectioned
haematoxylin
nucleus
simple
and
reticulum
was
blue) have
pulposus
was
aggregations
advanced
of
unbroken.
penetrating
at
eosin,
l0i
farther
little
in
the
findings
disc
content, fast
though region
but
nitric
and
plane.
chlorantine
the
first
signs
cellular
in the
in both
cells,
which
of
acid
structure
abnormal
than
6 to show
(Fig.
preparations
traces
of
consisted
the tissue
4 to Pt
the
in the
apparent,
was
no
there
sheath
sign
of any found
tissue
interspersed
with
8)Iitter
were with
collagen
fibres
and
this
SS.Sc
8 in the
nucleus
pulposus
mates.
(:
nucleus
pulposus
in
much
and stained
In conformity
normal.
changes
(Fig.
well
mucopolysaccharides
were
advanced
/
ofcartilaginous
freely
more
7) and
notochordal
mainly
was
the
normal
were
80.)
some
acid
in the
sections.
The
mucopolysaccharide
(stained
red
with
chlorantine
red).
The during
penetration early
of acid
post-natal
containing
no
primitive
nucleus
pulposus
are enlarged
Pt/-
nucleus No The
trace
central
was
of the
original
entirely
of notochordal was
cell
walls
were
the
early
post-natal
or were
still
seeming
to have
showed
some
discs
seemed
to
Between vertebral
NO.
and
2,
1961
nuclei in the
It was
was
left
and
eosin,
not
fifty clear
cells visible,
in the
by
cells
The
the whole
cell
of
the
nuclei
of the small
in
cellular
homogeneous
mucoid
in a thirty-nine-day-old
Pt/+.
seemed
days
(Fig.
had
and
age
most
This were
Fig.
cellular and
of both
many area
the
outside.
8)the
original
change area,
the normal
was
remains
from
obvious
substance, fibrosus
7).
immigrated at this
the
to contain
these
of the
mucoid
annulus
but
normal
ingression
The
cells.
whether
that
In the
continuing
in vacuoles
of
of mucoid
the
regions.
at
cartilage
rapidly
by a zone between
islands
existed
clearly
disintegration.
surrounded substance
surrounded
structure
reticulum.
proceeded
with
nuclei
from some of these
and
Pintail
was
largely
normally. a
sometimes
MAY
the
confined of
collagen.
end-plates 43 B,
been signs
and wall
pulposus
By ten days
blocks
nuclei.
cell was
isolate
haematoxylin
fibrocytes and
differentiate
fifty
with
present
clearly
surrounding
pulposus
large
original
structure
cells
into cell
nucleus many
to
in the
with
nucleus
of this
at birth.
divided
badly
cells, ofthe
than
the
it was
sufficient
collagen
central
days
penetration
notochordal
with
cells
infiltrated
was
mucoid
no sign
been
more
stained
A definite
almost There
area
the
less well
Pt/+
there
disc
fibrocytes.
had
into
at five
and
stained
of
and
Already
nuclei,
and
pulposus
substance,
mucopolysaccharides
life.
naterial
VOL.
studied
sagittal
blue
FIG.
in clearance
animal,
actual
was
2 per cent
the
differentiated:
7
FIG.
Pt/Pt
investigated
spine
with
or alcian
notochordal The
into
sections to those shown in Figures of the abnormal in fifty-day-old
with
391
MOUSE
were
ofthe
.
Similar
THE
pulposi
section
in Bouin’s
and
Ehrlich’s
4 to 6) the
consisted
it
whose
in
interest,
technique
IN
CHANGES
reduction
medical
PULPOSUS
1954).
At birth mice
this
ofits
to others.
embedded
Pi/
of
Because
NUCLEUS
hundred
days
Ossification occurred.
the
mucoid
of parts
of the
structure
annulus
of
the
fibrosus
Pt/+
on
disc
the
inside
of the
392
R. J. BERRY
There
formerly,
were
no
further
while
the
cell
nuclei
were
now
only
more
in the
first
seven
major
wall just
changes.
At
reticulum
of the
discernible.
weeks
In
after
250
birth
days
normal
fact
than
the
did
the
Pt/+
disc
was
still
clearly
lumbar
those
discs
was
fibrous
visible,
of
of normals
more
Pt/±
although
animals
in the
than
first
the
changed
seven
months.
1960)
to
DISCUSSION
The
effect
reduction takes
of
in the
place
on
the
Pintail
mitotic
rate
the
gene
on
in the
nineteenth
development
notochord
or twentieth
has
beginning
day).
The
normal and Pintail mice is that there are more the greatly accelerated age changes in the discs their
reduced
in
the
(1952)
with
and
Malinsk’(l959)
increasing
more
different
shown
on the
tenth
essential
notochordal of Pintail
(Berry day
of gestation
difference
be
a
(birth
between
newborn
cells in the former. Evidently mice are a direct consequence of
size.
Peacock
of man
only
been
rapid
age.
in Pintail
genetic
though
Many
breeds
age
changes
in the
mice.
This
condition
it is uncertain
authors
studied
changes
they The
that
differ
work
subject
changes
and
to disc
prolapse
gene
discs
in the
in the
(1951,
in dogs
by a single
in protruded
place
those
and
the
been
resemble
hence
in man.
is
on
already
closely
as is Pintail
discs
mouse
1952)
has
degeneration
characteristic
it is produced
take
from
ofHansen
to disc degeneration
of breeds is a breed
the
the
in which cells.
of dog discs
whether
have
described
respect
ofnotochordal
of certain
The
those
main
disappearance
dispositions
mentioned.
have
The
presumably in the
mouse.
and
Decker
Eckert
(1947) found differences between discs removed at operation and those taken from cadavers of similar ages, the most striking being stroma degeneration of the nucleus pulposus in the operatively removed discs. Hendry (1958) showed that protruded discs in man have a lowered capacity gel ofthe
to take up water: he ascribed nucleus-that is, the same
to occur shown was
normally that
the
only
the
uniform
Mice
which
that
is, they
carry
of
lower
than
content
the
exhibit
Pt
gene
varies
show
a genetically
The suggestion put results from a congenital basis of such a weakness
years.”
content and
“
polysaccharide
“
advancing
polysaccharide
strikingly
“
which
with
this to the loss ofor deterioration in the muco-protein changes as have been shown by Sylv#{233}n(1951) and others
such
determined
forward weakness in man
of
that
with
just
Mitchell,
a series of
age,
Hendry
a comparable
declining
hypothesis
it is difficult derangements.”
answers
the
difficulty
to understand why If there is a human
“
of muco-protein of the
of it would
be particularly
such a gene an age when
for premature their relative
liable
to disc
of
in the
intervertebral
elderly which
have
operation
normal
discs, onwards.
in
nucleus
pulposus,
discs. often, if not always, proof of the genetic to disc protrusion
lends itself easily to family studies, in the incidence of the condition. populations. it would presumably a “ weak back.” However, a
by the
annotation
Lancet
remain relatively causes accelerated
lesions
at decade
fourth
is that disc protrusion themselves. The direct difficult : a predisposition
expressed
the gene
the
a loss
(1961)
removed
series
from
in the third or fourth decade of life is not a subject which particularly since there are sex and occupational differences There may be a gene similar to Pintail widespread in human manifest itself in no other way than giving its possessors genetical
Billewicz
discs
weakness
in this paper of the discs would be very
and
prolapsed
comparatively
free ageing
early
(1958),
that
from major disc changes, carriers
in life.
People
without
ageing would reach a similar degree of disc degeneration immobility would tend to protect them from injury.
only
at
SUMMARY A description pulposus accelerated
in
the age
is given
of a mutation
intervertebral changes.
disc The
of
consequences
in the the
adults. of
mouse
which The
reduces
discs
a similar
of
mutation
am indebted to Professor Hans Grflneberg, F.R.S., for his constant June Denny for the photography, and to Mr A. J. Lee for the drawings. from the Medical Research Council which is gratefully acknowledged. I
THE
the these in
man
encouragement
size
of the
nucleus
mice
show
greatly
are
discussed.
and criticism,
The
work
was
JOURNAL
OF
BONE
supported
AND
to Miss by a grant
JOINT
SURGERY
GENETICALLY
CONTROLLED
DEGENERATION
OF THE
NUCLEUS
PULPOSUS
IN
THE
393
MOUSE
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R. J. (1960):
Genetical
J.
The
CHARNLEY,
(1952):
Studies
C., and DECKER, Surgery, 29, 447.
A.
ECKERT,
H.
GRUNEBERG,
Jour,zal HANSEN,
(1953):
51,
H. (1958): H.-J.
N.
G. W.
HOLLANDER,
Mouse.
F.,
and
LANCET
the
(1948):
STRONG,
of
Intervertebral
Skeleton
of
Interpretation
Hydration and
Study
the
Genetical
Nucleus
Research,
Journal
VII.
Congenital
1, 439.
Lancet,
Pulposus.
Discs.
Mouse.
ofDisc of
of the Nucleus
Joint
Surgery,
L. C. (1951):
42, Association
The
of
Pintail.
of the
of
Bone
1, 124.
and
Joi,zt
Hydrocephalus.
Disc
Degeneration
Acta
in Dogs.
Degeneration
in
Dog.
Ac/a
Orthopaedica Orthopaedica
Ii.
of Bone
Intervertebral
of England,
(1958):
on
XXVI.
conz,nunication.
of Heredity,
Symptomatology Surgeo,zs
Studies
Studies
280. A Pathological-anatomical
Journal
Journal
H.
JACKSON,
Pathological
Mouse.
of Herniation
327.
Supplementum C. (1958): The
Derangement.
ofthe
as a Cause
A Pathologic-anatomical
20, (1952):
Scamlinavica, HENDRY,
(1947):
Personal
(1951):
Scanclinavica, HANSEN, H.-J.
of Fluid
Genetical
of Genetics,
GRUNEBERG,
on the Skeleton
imbibition
Pintail,
179. Between Disc
Certain
Protrusions
Pulposus
40-B,
and its Relation
a Dominant
Mutation
Anatomical in
to Intervertebral
Disc
132.
the
Lumbar
Linked
Facts, Region.
with
Normal Annals
Brown
and
in the
Morbid, of
Royal
House
and
the
College
of
2, 273.
Annotation:
Physical
Changes
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