switch from systems microbiology to systems cell biology...
TRANSCRIPT
1
Due
dat
e fo
r PS
#3 h
as b
een
exte
nded
to
Thur
sday
11/
04/0
4(a
void
ing
elec
tion
day)
2
L14:
14
Lect
ures
pas
t and
11
to g
o
Part
I: ‘T
he c
ell a
s a
wel
l-stir
red
bior
eact
or’
topi
cs
- Lam
bda
phag
e ly
sis-
lyso
geny
sw
itch
- Syn
thet
ic g
enet
ic s
witc
h- S
witc
hes
as m
emor
y st
orag
e- C
hem
otax
is: p
erfe
ct a
dapt
atio
n or
not
?- S
ynth
etic
gen
etic
osc
illat
ors
mai
n as
sum
ptio
n
- wel
l-stir
red
reac
tor
- abs
ence
of c
hem
ical
gra
dien
ts(ju
stifi
catio
n: s
mal
l cel
ls, d
iffus
ion
mix
es)
3
Sw
itch
from
Sys
tem
s M
icro
biol
ogy
toS
yste
ms
Cel
l Bio
logy
The
impo
rtanc
e of
diff
usio
n an
d gr
adie
nts
for c
ellu
lar r
egul
atio
n
4
Part
II: S
yste
ms
Cel
l Bio
logy
‘Impo
rtanc
e of
gra
dien
ts a
nd d
iffus
ion
in c
ellu
lar r
egul
atio
n’A
fter t
wo
lect
ures
on
diffu
sion
and
reac
tion-
diffu
sion
equ
atio
ns,
we
will
focu
s du
ring
the
com
ing
lect
ures
on
the
follo
win
gbi
olog
ical
sys
tem
s:
1. E
ukar
yotic
che
mot
axis
Gra
dien
t sen
sing
in D
icty
oste
lium
(aka
‘am
oeba
’)2.
Com
putin
g th
e m
iddl
e of
a c
ell
Pol
e-to
-pol
e os
cilla
tions
in E
sche
richi
a co
li
3. S
elf o
rgan
izat
ion
of th
e cy
tosk
elet
on
5
Prok
aryo
tic v
ersu
s eu
kary
otic
cel
ls
e.g
E. c
oli,
cyan
obac
teria
~ 10
6 bp,
~ 5
000
gene
s6
Prok
aryo
tic v
ersu
s eu
kary
otic
cel
ls
e.g.
yea
st, a
moe
ba,
plan
ts, f
lies,
m
an &
mic
e ...
~ 10
9 bp,
~ 4
0000
gen
es !!
7
Topi
c I:
Spat
ial o
scill
atio
n in
E. c
oli
sim
ilar t
o ge
netic
osc
illat
ors,
but
now
we
cann
ot ig
nore
the
spat
ial d
imen
sion
s
biol
ogic
al fu
nctio
n:
dete
rmin
e th
e ce
nter
of t
he c
ell,
to p
repa
re fo
r pro
per c
ell d
ivis
ion
8
9gf
p-m
inC
10
GFP-minD
11gf
p-m
inE
is lo
caliz
edin
a ri
ng
minE
minD
12
gfp-minE
1314
Rec
ent r
esul
ts d
emon
stra
teth
at th
e m
in p
rote
ins
asse
mbl
e in
helic
es
15
Topi
c II:
Gra
dien
t sen
sing
my
favo
rite
mov
ie ..
.
neut
roph
il ch
asin
ga
bact
eriu
m
Dic
tyos
teliu
m (a
moe
ba)
sens
ing
a gr
adie
nt o
fcA
MP
sim
ilar t
o ch
emot
axis
of E
. col
i, bu
t now
we
cann
ot ig
nore
the
spat
ial d
imen
sion
s
16
17
cycl
ic A
MP
(cA
MP
) is
an a
ttrac
tant
for D
icty
oste
lium
(soc
ial a
moe
ba)
18
uni
form
ste
p in
cA
MP
cA
MP
gra
dien
t
19
Res
pons
e of
Dic
tyos
teliu
m to
cA
MP
initi
aldi
strib
utio
nt ~
3 s
stea
dy-s
tate
dist
ribut
ion
t ∞
unifo
rm s
tep
in c
AM
P
unifo
rm a
nd tr
ansi
ent
pola
rized
and
per
sist
ent
cAM
P g
radi
ent
20
Res
pons
e of
Dic
tyos
teliu
m to
pul
sed
cAM
P
21
geom
etry
of c
ell:
circ
ular
insi
de c
ytop
lasm
: wel
l-stir
red
insi
de m
embr
ane:
diff
usio
n-lim
ited
GFP
-PH
bin
ds s
peci
al li
pids
in m
embr
ane:
PIP
2 an
d P
IP3
22
The
mol
ecul
es in
the
mod
el:
23
aggr
egat
ion
of a
pop
ulat
ion
of a
moe
ba
biol
ogic
al fu
nctio
n:de
velo
pmen
t of a
mul
ticel
lula
r stru
ctur
e24
PH-GFP
powerful reporter
25
Topi
c III
: Sel
f-org
aniz
atio
n of
the
cyto
skel
eton
Cen
ter f
indi
ng in
an
euka
ryot
ic c
ell:
fissi
on y
east
The
impo
rtanc
e of
the
cyto
skel
eton
26
27C
hang
et a
l.28
Pos
itive
feed
back
as
a m
echa
nism
sfo
r spo
ntan
eous
cel
l pol
ariz
atio
n ?
29
Cel
ls a
rres
ted
in G
1
Ove
rexp
ress
ed c
dc42
-GFP
(dom
inan
tly a
ctiv
e)
All
inte
rnal
and
ext
erna
lcu
es re
mov
ed
1 ho
ur a
fter i
nduc
tion
of c
dc42
-gfp
3 ho
ur a
fter i
nduc
tion
of c
dc42
-gfp
Wed
lich-
Sol
dner
et a
l.S
cien
ce 2
99, 1
231
(200
3)30
dyna
mic
s of
sym
met
rybr
eaki
ng
31
Pos
itive
feed
back
thro
ugh
cyto
skel
etal
med
iate
d cd
c42
trans
port
32
mor
e in
itial
cdc
42 o
n m
embr
ane,
mor
e ca
psst
rong
er fe
edba
ck, l
ess
caps
mod
el:
expe
rimen
ts: