Jax5_Protocol
Project
protocol
—
Contents
Workflow
and
sampling
Equipment
and
supplies
Reagents
and
solutions
Procedure
Additional
information
Data
Workflow
and
sampling
Step |
Procedure
done |
Dates |
|
1 |
JAX
breeding
performance
data
was
collected
from
Production
Colonies
(pedigreed
expansion
stocks)
from
which
JAX®
Mice
are
shipped.
|
December
2005
to
June
2008
|
female
reproductive/
breeding
performance
|
2 |
Males
and
females
were
paired,
and
in
addition,
trios
were
set
up
for
NOD.Cg-Prkdcscid
Il2rgtm1Wjl/SzJ). |
December
2005
to
June
2008
|
|
3 |
Cages
were
monitored
by
JAX
animal
caretakers
for
the
duration
of
the
study.
|
December
2005
to
June
2008
|
|
4 |
The
number
of
pups
born
and
date
of
birth
were
recorded,
and
the
number
and
sex
of
surviving
pups
were
recorded
at
the
time
of
weaning
(usually
3-4
wks
of
age).
|
December
2005
to
June
2008
|
|
Equipment
and
supplies
- Vivarium
for
breeding
mice
- Essentials
for
recording
female
mice
breeding/reproductive
performance
- Gloves,
masks,
laboratory
gown,
and
head
wear
- Large
forceps
Investigator
Notes:
"All
mouse
colonies
(even
within
the
same
facility)
are
different
and
breeding
performance
may
vary.
Thus,
the
breeding
performance
data
in
this
study
should
be
used
as
a
guideline
to
indicate
strain
breeding
potential
and
to
help
identify
potential
breeding
problems."
Reagents
and
solutions
Alcohol
for
disinfection
Procedures
Data
submission
&
curation
Data
were
submitted
to
MPD
by
litter
per
dam.
To
standardize
the
study
and
ensure
data
are
maximally
useful
for
comparisons
across
strains,
the
following
guidelines
were
followed
to
omit
data
that
did
not
meet
certain
criteria.
MPD
criteria
1.
Dam
age
at
mate:
3-6
wks
of
age
(e.g.,
data
were
excluded
from
females
that
were
first
mated
at
>6
wks
of
age)
2.
Max
age
of
dam
at
birth
of
last
litter:
40
wks
of
age
3.
Interval
between
litters
for
dam:
≤10
wks
(e.g.,
data
were
excluded
if
breeders
were
not
productive
within
a
10
wk
window).
If
number
of
pups
born
was
submitted
as
less
than
number
of
pups
weaned,
the
value
reported
for
'pups
born'
was
adjusted
to
equal
to
the
number
of
'pups
weaned',
assuming
there
was
an
initial
miscount
as
a
result
of
minimally
disturbing
the
family
unit.
MPD
notes:
Less
than
4%
of
submitted
data
did
not
meet
our
requirements.
These
data
are
omitted
from
the
data
file
and
not
used
for
computation.
Strain
performance
data
have
been
summarized
in
two
ways:
1.
By
dam:
summary
of
all
litters
per
dam,
then
summarized
for
strain
2.
By
litter:
summary
of
all
litters
(regardless
of
dam)
per
strain
A
summary
table
from
this
study
is
available
in
The
Jackson
Laboratory
Handbook
on
Genetically
Standardized
Mice,
Sixth
Edition
(2009).
To
order
the
manual
click
here.
For
Breeding
Strategies
for
Maintaining
Colonies
of
Laboratory
Mice
go
here.
For
convenience
we
have
made
the
following
information
publicly
available:
Table
1.
Strategies
for
maximizing
productivity
of
a
breeding
colony.
Table
2.
Reproductive
characteristics
for
most
inbred
strains
of
laboratory
mice.
Table
3.
Environmental
factors
that
can
affect
breeding.
Table
4.
Breeding
problems
and
possible
resolutions.
Additional
information
from
The
Jackson
Laboratory
Handbook
on
Genetically
Standardized
Mice
Table
1.
Strategies
for
maximizing
productivity
of
a
breeding
colony.
|
Factors
|
Action
to
promote
successful
breeding |
Comments |
1 |
When
to
set
up
breeding |
•
Mate
mice
when
they
are
6–8
weeks
old.
|
•
Note
that
it
is
not
unusual
for
the
first
litter
to
be
smaller
than
the
second
or
third,
which
are
typically
the
largest. |
2 |
When
to
foster
pups |
•
Foster
pups
-
if
the
mother
does
not
"nest"
the
pups
right
away
but
leaves
them
scattered
around
the
cage
,
or
-
if
milk
spots
do
not
appear
in
the
pups
by
the
time
they
are
24-hours
old. |
•
If
you
need
offspring
from
a
female
who
is
a
poor
mother,
plan
ahead
to
have
foster
mothers
ready
when
she
gives
birth.
|
| •
Housing
2
females
together
will
often
allow
them
to
work
together
and
successfully
raise
2
litters.
|
3 |
When
to
replace
breeding
pairs
for
optimal
performance |
•
Replace
breeding
pairs
as
their
reproductive
performance
declines
(typically
6–8
months
of
age;
see
Table
2.)
|
•
A
colony
of
mixed-age
breeders
produces
a
more
consistent
quantity
of
pups
than
does
a
colony
with
mice
of
the
same
age.
|
| •
For
a
large
colony,
maintain
a
stable
supply
of
breeding
pairs
at
various
ages
by
replacing
a
specific
percentage
on
a
weekly
or
monthly
basis.
|
4 |
When
to
replace
individual
female
breeders
|
•
Replace
female
breeders
when
they
-
do
not
produce
a
litter
within
60
days
of
pairing
(unless
this
delay
is
normal
for
the
strain),
or
-
do
not
produce
a
litter
within
60
days
of
their
last
-
produce
litters
but
pups
do
not
survive
for
2–3
litters. |
- |
5 |
When
to
replace
individual
male
breeders |
•
Replace
male
breeders
-
when
they
reach
1
year
of
age,
or
-
if
they
are
infertile
with
a
young,
fertile
female. |
- |
6 |
When
to
cull
a
litter
|
•
Reduce
the
number
of
pups
in
a
litter
if
the
mother
is
having
problems
feeding
the
pups. |
•
Some
mothers
may
be
unable
to
provide
milk
for
more
than
a
few
pups. |
|
•
For
segregating
strains,
remove
unwanted
pups
as
soon
as
they
can
be
phenotyped
or
genotyped. |
7 |
How
to
improve
breeding
behavior |
•
With
young
females,
use
experienced
males. |
•
Males
mature
later
than
females;
therefore
age
at
first
litter
for
same-aged
breeding
pairs
is
often
determined
by
the
male. |
|
•
Isolate
males
for
2
weeks
before
pairing.
|
| •
Rotate
males
within
a
strain
among
cages. |
Table
2.
Reproductive
characteristics
for
most
inbred
strains
of
laboratory
mice.
|
Characteristic |
Normal
range |
Comments |
1 |
Sexual
maturity |
4–8
wks
of
age |
Males
usually
reach
sexual
maturity
by
6
weeks,
females
by
4–6
weeks. |
2 |
Estrous
cycle |
4-day
or
5-day
cycle |
The
normal
cycle
can
be
interrupted
by
mating,
pheromones,
vibration,
noise,
and
other
environmental
stresses. |
3 |
Postpartum
estrus |
6-
to
8-hr
period |
This
is
the
estrous
period
females
enter
within
a
few
hours
after
giving
birth.
If
a
male
is
in
the
cage,
mating
and
pregnancy
are
likely. |
4 |
Ovulation
rate
|
4-12
ova
per
estrus |
Strain
dependent.
|
5 |
Litter
size
|
2–12+
pups
(aver.
6–8
pups) |
Strain
dependent.
Pattern
is
for
litter
size
to
increase,
reach
a
peak
at
about
3–4
months
of
age,
then
start
decreasing. |
6 |
Fertility
rate |
50–100% |
With
some
strains,
all
pairs
of
mice
are
fertile;
with
others,
as
few
as
50%
are. |
7 |
Gestation
length |
18–21
days |
Gestation
length
is
typically
18–19
days
for
most
strains;
may
be
longer
if
litters
are
smaller
(4
or
fewer
pups)
or
mothers
are
older. |
8 |
Time
between
litters |
22–50
days |
Typically
the
shortest
time
between
litters
occurs
between
3–4
months
of
age
(between
the
first
and
second
litter),
then
progressively
increases. |
9 |
Generation
time |
About
10
wks |
Strain
dependent.
Conception-to-conception
time
is
determined
as
follows:
3
weeks
gestation,
3–4
weeks
suckling,
1–3
additional
weeks
until
sexual
maturity.
But,
generation
time
for
the
first
litter
is
often
longer. |
10 |
Weaning
age |
21–28
days |
In
husbandry
context,
the
age
at
which
pups
are
removed
from
their
mother,
not
when
they
start
eating
solid
food.
Varies
among
strains;
depends
on
weanling
size
and
maturity.
Most
strains
are
weaned
at
21
days,
some
at
28
days.
Do
not
remove
pups
from
mother
before
17
days
unless
they
are
transferred
to
a
foster
mother. |
11 |
Total
litters |
2–8 |
Total
litter
number
varies
by
strain.
A
total
of
4+
litters
is
typical,
but
some
strains
produce
as
few
as
1
or
2
litters. |
12 |
Reproductive
lifespan
(female) |
Terminates
at
6-12
mo.
of
age |
Strain
dependent.
For
inbred
strains,
fecundity
usually
begins
to
decrease
with
the
3rd
litter.
By
6–8
months,
some
females
become
infertile,
and
litter
size
for
most
females
of
most
strains
has
diminished
to
the
point
that
it
is
more
economical
to
set
up
a
new
breeding
pair. |
13 |
Reproductive
lifespan
(male) |
Terminates
at
12-14
mo.
of
age |
Strain
dependent.
Fertility
in
some
strains
decreases
starting
at
10
months. |
14 |
Delayed
implantation |
n/a |
Implantation
normally
occurs
during
the
fifth
day
after
conception.
However,
if
a
female
is
nursing,
implantation
may
be
delayed
for
more
than
a
week,
during
which
time
embryonic
development
is
held
in
suspension. |
15 |
Seasonal
breeding
fluctuations |
n/a |
Some
strains
are
susceptible
to
changes
in
breeding
behavior
based
on
season. |
Table
3.
Environmental
factors
that
can
affect
breeding
|
Factors |
Action
to
promote
successful
breeding |
Comments |
1 |
Location
of
cages |
•
Avoid
locating
cages
near
a
heavily
trafficked
or
noisy
area,
such
as
near
a
door
or
sink
or
a
loudspeaker
used
for
paging. |
•
Changes
in
levels
of
noise
and
vibration
can
decrease
breeding
performance
and
may
induce
mothers
to
resorb
litters,
cannibalize
their
pups,
or
stop
breeding. |
| •
Place
cage
racks
several
inches
from
the
wall
to
prevent
building
vibrations
from
transferring
to
the
cages. |
•
Construction-related
noise
and
vibrations
may
be
especially
problematic.
|
2 |
Lighting |
•
Maintain
a
single,
consistent,
lighting
cycle.
The
most
common
cycles
are
14:10
(on:off)
and
12:12. |
•
Disruption
of
the
light
cycle
may
have
an
adverse
effect
on
breeding. |
| •
For
wild-derived
mice,
use
less
intense
lighting. |
3 |
Barometric
pressure |
•
Maintain
a
stable
barometric
pressure. |
•
Falling
barometric
pressure
can
cause
some
strains
to
become
hyperactive,
which
reduces
breeding
performance. |
4 |
Temperature
and
humidity |
•
Keep
the
temperature
at
16–26°C
(64–79°F)
|
•
Thermoneutral
temperature
for
mice
is
around
27–28°C
(80–82°F).
In
contrast,
for
humans,
it
is
about
22–23°C
(72–74°F).
|
| •
Keep
the
humidity
at
40–60%.
|
5 |
Air
quality
and
odors |
•
Keep
the
room
air
fresh,
free
from
strong
odors.
|
•
Mice
are
extremely
sensitive
to
strong
or
noxious
odors,
but
they
like
their
own
scent
to
be
strong
in
their
environment.
|
| •
Establish
a
"no
perfume"
policy
for
caretakers,
technicians,
or
anyone
who
works
with
the
mice. |
•
Noxious
fumes
may
reduce
breeding
performance. |
| •
Use
clean
forceps
or
clean
(or
new)
gloves
for
each
cage. |
6 |
Handling |
•
Work
gently,
slowly,
and
quietly
when
handling
breeding
mice.
|
•
Laboratory
mice
respond
best
to
calm,
consistent
handling. |
•
Try
to
regularly
assign
caretakers
to
the
same
cages
so
that
the
mice
receive
consistent
care
with
familiar
handling
and
odors.
|
| •
Avoid
changing
cages
more
often
than
once
a
week;
if
females
are
ready
to
give
birth,
skip
cage
changing
until
pups
are
2
days
old
or
you
can
see
milk
spots. |
•
Often,
mice
do
not
like
new
technicians. |
| •
Minimize
handling
and
checking
on
the
mice,
especially
if
mice
are
pregnant
or
giving
birth,
or
have
new
litters.
|
•
Wild-derived
mice
are
especially
sensitive
to
handling
stress. |
| •
Unless
absolutely
necessary,
do
not
handle
pups
until
they
are
3
days
old. |
7 |
Bedding
and
nesting
material |
•
Provide
nesting
materials
in
the
cage,
especially
if
bedding
(such
as
pellets
from
corn
cob)
does
not
lend
itself
to
nesting. |
•
The
addition
of
material
such
as
Kimwipes®
or
Nestlets®
can
promote
nesting.
|
| •
Nesting
behavior
is
strain
dependent. |
8 |
Diet |
•
Provide
food
with
a
dietary
fat
content
of
4–11%
fat
w/w. |
•
The
optimal
percentage
of
fat
in
the
diet,
with
respect
to
fecundity,
is
strain
dependent.
Optimal
fat
content
ranges
from
4–12%
w/w;
a
commercially
available
breeder
diet
with
9%
fat
w/w
works
well
for
most
strains
of
mice. |
| •
If
mice
have
bad
teeth,
broken
teeth
(e.g.,
from
gnawing
or
malocclusion),
no
teeth,
or
other
phenotypes
that
affect
their
ability
to
eat
normal
mouse
food,
provide
an
alternate
food
supply,
perhaps
either
ground
or
dampened
food. |
| •
If
mice
cannot
reach
the
"normal"
water
or
food
supply,
provide
access
to
both
on
the
cage
floor. |
Table
4.
Breeding
problems
and
possible
resolutions.
|
Problem
|
Possible
resolution |
1
|
Mice
are
not
breeding. |
A |
Make
sure
you
have
male
and
female
breeders. |
B |
Add
nesting
material
specifically
designed
for
that
purpose. |
C |
Try
a
different
diet,
for
example,
one
with
more
or
less
fat. |
D |
Minimize
stress—including
human
contact
with
the
mice
and
activity
and
noise
in
the
room.
Construction-related
vibrations,
even
outside
the
building,
can
disrupt
breeding.
If
possible,
move
mice
to
a
quieter
area.
|
E |
Try
a
14:10
light
cycle. |
F |
Make
sure
mice
are
healthy
and
able
to
breed
(for
example,
not
too
obese
or
too
old).
Try
healthier,
younger
animals. |
G |
If
you
never
see
vaginal
plugs,
try
a
new
male. |
2
|
Females
are
not
getting
pregnant. |
H |
Determine
whether
the
problem
is
the
male
or
female:
pair
a
proven
breeder
female
with
the
male
and
a
proven
breeder
male
with
the
female. |
I |
Surgically
evaluate
the
reproductive
tract.
If
the
female
appears
normal,
try
low
dose
gonadotrophins,
ovarian
transplant,
IVF;
if
the
male
appears
normal,
try
IVF. |
J |
Research
the
strain
reproductive
characteristics.
For
a
transgenic,
check
the
effect
of
the
transgene
on
breeding.
For
a
strain
carrying
a
mutation,
check
the
effect
of
the
mutation.
Adjust
the
breeding
strategy
accordingly. |
3 |
Mice
get
pregnant
but
you
never
see
pups
(females
are
resorbing
fetuses). |
D
(above) |
The
most
common
cause
of
fetal
resorption
is
stress. |
4 |
Individual
breeders
are
not
producing
an
expected
number
of
pups. |
B,
C,
D,
E,
F,
H,
J
(above) |
- |
5 |
Females
give
birth,
but
don’t
raise
their
pups. |
D,
J
(above)
K |
If
you
introduced
a
male
to
a
cage
with
pups,
he
may
have
killed
them.
Wait
to
add
a
male
until
all
pups
have
been
weaned
and
removed. |
6 |
Pups
disappear
or
do
not
survive. |
|
7 |
Colony
productivity
has
dropped. |
L |
Check
for
environmental
factors
that
might
have
changed.
Consider
room
conditions
(temperature,
vibrations,
building
construction,
odors,
etc.),
caretaker,
and
diet.
If
more
than
one
cage,
area,
or
strain
is
affected,
expand
the
search.
If
possible,
restore
environment
to
previous
conditions. |
Data
&
information
collected
*
=
accessioned
as
MPD
measurement
L)
=
local
parameter
•
=
supplementary
data
or
information
•
JAX®
Animal
Facility
•
Mating
type
(pair,
trio)
•
Dates
of
birth
(dam),
mating,
birth
of
litter
L)
Litter
number
(order)
*
Number
of
pups
born
per
litter
•
Number
of
males
weaned
per
litter
•
Number
of
females
weaned
per
litter
Data
determined
or
derived:
L)
Age
of
dam
at
mating•
Interval
between
consecutive
litters
*
Latency
to
first
litter
(after
breeding
cage
established)
L)
Age
of
dam
at
birth
of
every
litter
L)
Age
of
dam
at
birth
of
first
litter
•
Interval
between
consecutive
litters
*
Total
number
of
pups
weaned
per
litter
•
Percent
females
per
litter
*
Wean
to
born
ratio
per
litter
*
Total
number
of
litters
per
dam
*
Mean
interval
between
consecutive
litters
per
dam
*
Total
number
of
pups
born
per
dam
*
Total
number
of
pups
weaned
per
dam
*
Mean
number
of
pups
born
per
number
of
litters
born
*
Mean
number
of
pups
weaned
per
number
of
litters
born
*
Percent
females
weaned
per
dam
MPD
derived:
*
Parenting
index
(wean
to
born
ratio
per
dam,
computation
requires
that
at
least
3
litters
born
and
at
least
10
pups
born
total)
*
Fecundity
index
(total
pups
weaned
per
dam
divided
by
mean
interval
between
litters,
computation
requires
that
at
least
3
litters
born
and
at
least
10
pups
born
total)
*
Sex
ratio
(female
to
male
ratio
per
dam,
computation
requires
that
at
least
3
litters
born
and
at
least
10
pups
born
total)
|
|
only
Test age:
6-40wks