BIOL 142 Lecture Notes - Lecture 26: Regulatory Sequence, Chromatin Remodeling, Deoxyribonuclease
30 Apr 2018
School
Department
Course
Professor
!"#$%&%'()*+",-&."/
1)#Describe#the#general#mechanisms#of#eukaryotic#gene#regulation#within#and#
outside#the#nucleus.#
2)#Test#the#role#of#chromatin#remodeling#in#transcriptionally#active#areas#of#the#
genome#using#the#enzyme#DNAase.#
3)#Describe#the#common#promoter#and#variable#regulatory#elements#of#
eukaryotic#genes
0"%"("12$"//&)%(,3#%'"/(#44)5("67#$8)-&,(,"44/( -)($"/2)%9(-)("%.&$)%:"%-#4(,3#%'"/(
#%9(,#6/"(9&/-&%,-(,"44( -82"/(-)(9"."4)2;(
<%(:64-&,"4464#$("67#$8)-"/=(9&>>"$"%-('"%"("12$"//&)%(&/($"/2)%/&*4"(>)$(
,$"#-&%'(9&>>"$"%-(,"44( -82"/=(#$$#%'&%'(-3":(&%-)(-&//6"/=(#%9(,))$9&%#-&%'(-3"&$(
#,-&.&-8
?)(-6$%()%(#('"%"(#-(#(-&:"(#%9(24#,"
○
@""9"9(-)($"'64#-"(9"."4)2:"%-
A$$)$/(4"#9(-)(2#-3)238/&)4)'8
§
○
B
C3#-(&-(-#7"/(>)$(#(9&24)&9(2$",6$/)$(,"44(-)(9"."4)2(&%-)(#%()$'#%&/:
D"&)/&/(4"#9/(-)('"%"-&,#448(9&/-&%,-(,"44/
E2"$:(F("''(G(%"5(9&24)&9(,"44(#%9(&%9&.&96#4(&%(%"1-('"%"$#-&)%(>)$(
)$'#%&/:
§
○
B
C&-3(>"5("1,"2-&)%/=(#44(,"44/(&%(#%()$'#%&/:(3#."(-3"(/#:"('"%"/=(*6-(-3"8("12$"//(
-3":(9&>>"$"%-48;(
H)$("1#:24"=(*)-3(*$#&%(#%9(4&."$(,"44/(-$#%/,$&*"(I3)6/"7""2&%'J('"%"/(-3#-(
,)9"(>)$("%K8:"/(#%9()-3"$(:)4",64"/("//"%-(-)(-3"(/6$.&.#4()>(#44(,"44/;(
A12$"//"9(&%(*)-3(,"44( -82"/
L)-3(,"44/(%""9(:"-#*)4&/:(>)$("%"$'8
§
○
M$"(%)-(/2",&>&,(-)(2#$-&,64#$(,"44(-82"/
○
B
N)5"."$=(4&."$(,"44/(-$#%/,$&*"(/):"('"%"/(>)$(4&."$O/2",&>&,(2$)-"&%/=(#%9(*$#&%(
,"44/(-$#%/,$&*"(/):"('"%"/(>)$(*$#&%O/2",&>&,(2$)-"&%/;(
P%48("12$"//"9(&%(,"$-#&%(24#,"/
○
L$#&%(,"44/( >)$(%"6$)%/(-)(,)%96,-(&-/(#,-&.&-&"/
○
B
?3"(9&>>"$"%,"(&%(-3"(2$)96,-&)%()>(2$)-"&%/(&/(96"(-)(differential*gene*
expression;
B
1.#Control#of#Gene#Expression#in#Eukaryotes
P."$.&"5()>(Q('"%"$#4(4"."4/(-)($"'64#-"(&>(#('"%"(&/(#,-&."(&%(#("67#$8)-&,(,"44B
E):"(3#22"%(&%(-3"(%6,4"6/(RSOTU(#%9(/):"(&%(,8-)24#/:(RVOQUB
W"'64#-&)%()>("67#$8)-&,('"%"(&/(:)$"(,):24"1(*",#6/"(2$)7#$8)-&,('"%"/(9)%X-(
3#."(%6,4"&
B
P."$.&"5()>('"%"($"'64#-&)%Y(
A67#$8)-&,('"%"("12$"//&)%(,#%(*"($"'64#-"9(#-(T(/-"2/(within*the*nucleus
Z3$):#-&%($":)9"4&%'Y([@M(&/(2#,7#'"9(5&-3(2$)-"&%/(&%-)(,):24"1(
/-$6,-6$"/(-3#-(:6/-(*"()2"%"9(>)$(-$#%/,$&2-&)%(-)(),,6$;
S;
?$#%/,$&2-&)%#4($"'64#-&)%Y(?$#%/,$&2-&)%(,#%(*"(&%&-&#-"9()%48(53"%(
/2",&>&,(2$)-"&%/(*&%9(-)(-3"(2$):)-"$(#%9(-)(/2",&>&,($"'64#-)$8(
/"\6"%,"/;
<%()2"%([@M(R4"//(,):2#,-U=(-3"$"(#$"($"'64#-)$8(9):#&%/(5&-3&%(
-3"([@M(-3#-(9"-"$:&%"(53"-3"$(#('"%"(5&44(*"("12$"//"9
§
A1Y(2$):)-"$Y($"'64#-"(53#-('"-/(-$#%/,$&*"9
§
M4/)($"'64#-)$8([@M(/"\6"%,"/(%""9"9(-)(9$&."("12$"//&)%
§
];
M4-"$%#-&."(/24&,&%'(#44)5/(#(/&%'4"('"%"(-)(,)9"(>)$(/"."$#4(9&>>"$"%-(
2$)96,-/;
^$),"//&%'(W@M
§
,[@M/(>$):(:W@M
§
W@M(&/(2$),"//"9(&/(#(-3&$9(5#8()>($"'64#-&%'("67#$8)-&,('"%"/
§
T;
B
A67#$8)-&,('"%"("12$"//&)%(,#%(*"(>6$-3"$($"'64#-"9(#-(T(/-"2/(within*the*
cytoplasm;
B
P%,"(#%(:W@M(&/(&%(-3"(,8-)24#/:=('"%"("12$"//&)%(&/(,)%-$)44"9(*8(:)4",64"/(
-3#-($"'64#-"(-3"(>)44)5&%'Y
?3"(4&>"(/2#%()>(:W@M/V;
?3"(">>&,&"%,8()>(-$#%/4#-&)%_-)(-$#%/4#-"()$(%)-(-)(-$#%/4#-"
Z#%(,3":&,#448(:)9&>8($&*)/):"/(-)(,3#%'"($#-"/()>(-$#%/4#-&)%
§
`;
?3"(#,-&.#-&)%()$(&%#,-&.#-&)%()>(2$)-"&%(2$)96,-/
Z"44(/&'%#4&%'
§
^3)/23)$84#-&)%(&/(#(2)/-O-$#%/4#-&)%#4(:)9&>&,#-&)%
§
Q;
1. ?3"(/&%'4"=(6%&."$/#4($"'64#-)$8(:",3#%&/:(&%("67#$8)-"/(>)$(,)%-$)44&%'('"%"(
"12$"//&)%(&%,469"/Y(
MU(,)%-$)4()>(-3"('"%"/(-$#%/,$&*"9(#%9(-3"($#-"(-3"8(#$"(-$#%/,$&*"9;(
LU(,)%-$)4()>(-3"(2$),"//&%'()>(:W@M(#>-"$(&-(&/(-$#%/,$&*"9(>$):([@M;(
ZU(,)%-$)4()>(:W@M(&%(-3"(,8-)24#/:(#>-"$(&-(4"#."/(-3"(%6,4"6/=(&%,469&%'(
,3#%'"/(-)(:W@M(*">)$"(-$#%/4#-&)%(*"'&%/;(
[U(,)%-$)4()>(2)482"2-&9"/(#>-"$(-3"8(3#."(*""%(/8%-3"/&K"9(*6-(*">)$"(-3"8(#$"(
>6%,-&)%#4;(
E)*All*of*these*mechanisms*are*used;*there*is*no*single*universal*mechanism.*
A67#$8)-&,('"%"($"'64#-&)%(&/(,):24"1
○
W"'64#-&)%(),,6$/(#-(#(.#$&"-8()>(4"."4/(&%(-3"(%6,4"6/(#%9(,8-)24#/:
○
2.#Chromatin#remodeling#is#required#prior#to#gene#transcription.
W"'64#-&%'(9"'$""()>(,):2#,-&)%()>([@M(#$)6%9(2$)-"&%(a,3$):#-&%B
Z3$):#-&%($":)9"4&%'(a3)5(-&'3-48(5"(5&%9([@M(#$)6%9(2$)-"&%
?3"(:)$"(-&'3-48(8)6(5&%9([@M=(-3"(4"//(#,,"//&*4"( $"'64#-)$8([@M(
$"'&)%/(#$"(-)(2#$-%"$&%'(2$)-"&%/(4&7"(W@M(2)48:"$#/"
W@M(2)48:"$#/"(%""9/(-)(*&%9(-)(#(2$):)-"$(-)(7%)5(53"$"(-)(
*&%9(>)$(-$#%/,$&2-&)%
§
?&'3-(5&%9&%'(,#%(:#7"(2$):)-"$(&%#,,"//&*4"
§
○
B
?5)(9&>>"$"%-(7&%9/()>(,3$):#-&%(,#%(*"(9&/-&%'6&/3"9(*8(/-#&%&%'(-3"(%6,4"6/;(
Euchromatin /-#&%/(4&'3-48
It*contains*DNA*that*is*transcribed*into*mRNA
Transcriptionally*active*DNAb
§
[@M(&/(%)-(5)6%9(."$8(-&'3-48(a4))/"(,)%>&'6$#-&)%
?3&/($"'&)%()>(-3"(,3$):)/):"(3#/(4))/"(,3$):#-&%b
§
@)-(#(4)-(&%()%"(/2)-(-)(2&,7(62(#(4)-()>(98"
§
○
Heterochromatin /-#&%/(9"%/"48(#%9(&/('"%"$#448(%)-(-$#%/,$&*"9;(
Any*genes*in*heterochromatin*are*thus*inactivated.
Largely*silent*DNAb
§
?&'3-48(5)6%9=(3&'348(,)%9"%/"9
§
[8"(&/(#*/)$*"9(-)(#('$"#-"$(9"'$""(-)(/-#&%(9#$7"$
§
○
B
N"-"$),3$):#-&%(&/(&%(>)6%9(&%(-3"(&%#,-&."(c(,3$):)/):"()>(:#::#4/;
P%"()>(-3"(c(,3$):)/):"/(&%("#,3(,"44( )>(#(>":#4"(&/(&%#,-&.#-"9(*8([@M(
:"-384#-&)% "#$48(&%(9"."4)2:"%-;
Z)649("12$"//(-5&,"(#/(:6,3(&%(c()>(:#4"=()$(3#4>()>(cc(&%(>":#4"
○
<%(>":#4"/=()%"()>(-3"(c(,3$):)/):"/
○
P%"(c(&/(3&'348(:"-384#-"9(#%9(4"#9/(-)(c(,3$):)/):"(/&4"%,&%'
○
B
?3"(,3$):)/):"($":#&%/(,)%9"%/"9(#%9(#22"#$/(#/(#(Barr*body 6%9"$(-3"(
:&,$)/,)2";(
Condensation*physically*prevents*DNA*from*being*transcribed
○
L#$$(*)98(-#7"/(62(#(4)-()>(/-#&%=(/)(#22"#$/(9#$7
○
?3#-(&/(#(/&4"%,"9(c(,3$):)/):"
○
E&4"%,"9(c(,3$):)/):"(,3#%'"/(>$):(,"44(-)(,"44
<>(-3"$"(&/(#(9&/"#/"=(&/("12$"//"9(3#4>(-3"(-&:"
§
○
B
2. M(>)$:()>(-$#%/,$&2-&)%#448(#,-&."(,3$):#-&%(&/($">"$$"9(-)(#/Y(
MU(#(L#$$(*)98;(
LU(3"-"$),3$):#-&%;(
ZU(#(,3$):)/):";(
D)*euchromatin.*
AU(@)%"()>(-3"/"
?3"(2#-"$%#448(#%9(:#-"$%#448O&%3"$&-"9(cO,3$):)/):"/(#$"('"%"$#448(/36-(9)5%(5&-3(
"\6#4(2$)*#*&4&-8;(
C3#-(&/(-3"('"%"-&,(,)%/"\6"%,"()>(-3&/($#%9):(cO,3$):)/):"(&%#,-&.#-&)%d(B
M44(3"-"$)K8')-"/(>)$(#(2#$-&,64#$(cO4&%7"9(-$#&-(5&44("13&*&-(mosaicism;(
<%(#(:)/#&,=(8)6(3#."(/):"(,"44/(-3#-(3#."(#('&."%(23"%)-82"(#%9()-3"$(
,"44/(5&-3(#%)-3"$(23"%)-82"
○
B
?3"(-)$-)&/"/3"44(,#-(&/(#(,)::)%("1#:24";(C3&4"(:64-&24"('"%"/(,)%-$&*6-"(-)(
>"4&%"(,)#-(,)4)$=(-3"('"%"($"/2)%/&*4"(>)$(-3&/(23"%)-82"(&/(cO4&%7"9=(#%9(3#/(#%(
)$#%'"(#%9(#(*4#,7(#44"4"
?82&,#448(>":#4"
○
N#."(-)(*"(3"-"$)K8')6/
L4#,7(2#-,3"/(>)$:(96"(-)(&%#,-&.#-&)%()>()-3"$(,3$):)/):"(5&-3(
-3"()$#%'"(#44"4"
§
?3"()$#%'"(2#-,3"/(#$"()$#%'"(*",#6/"(-3"(,3$):)/):"(5&-3(-3"(
*4#,7(,)4)$#-&)%(#44"4"(')-(/&4"%,"9
§
○
^#-,3"/(9&>>"$(*",#6/"()>(9"#,-&.#-&)%($#%9):48()>(,3$):)/):"/
○
B
3. Z#%(#(-)$-)&/"/3"44(,#-(*"(:#4"d(
MU(e"/=(#44(,#-/()>(-3&/(23"%)-82"(#$"(:#4";(
LU(@)=(&-(&/(%)-(2)//&*4"(>)$(:#4"(,#-/(-)(3#."(-3"(-)$-)&/"/3"44(23"%)-82";(
C)*Yes,*in*rare*circumstances,*tortoiseshell*males*cats*are*possible.*
W"/64-/(>$):(%)%9&/+6%,-&)%(#%9(3#."(#%(cce(:#4"
○
E&4"%,&%'()>(cf/(,#%(),,6$
○
[U(e"/=(*)-3(:#4"/(#%9(>":#4"/(#$"("\6#448(4&7"48(-)(*"(-)$-)&/"/3"44;
4. C3&,3()>(-3"(>)44)5&%'(/-#-":"%-/($"'#$9&%'(c(&%#,-&.#-&)%(&%(:#::#4/(&/(HM!EAd(
MU(?3"(2$),"//(&/("%-&$"48($#%9):;(
LU(c(&%#,-&.#-&)%(:#8(),,#/&)%#448(),,6$(&%(:#4"/;(
C)*This*process*ensures*a*homogenous*phenotype*in*heterozygotes.
[)"/%f-(9"/,$&*"("1#:24"()>(-)$-&)6/(/3"44(,#-
○
[U(c(&%#,-&.#-&)%(),,6$/("#$48(&%(":*$8)%&,(9"."4)2:"%-;
?3"("4#*)$#-"(/-$6,-6$"()>(,3$):#-&%(#44)5/([@M(-)(*"(2#,7#'"9(&%(-3"(%6,4"6/;
Chromatin*contains*nucleosomes,*repeating,*beadlike*structures*that*consist*
of*negatively*charged*DNA*wrapped*twice*around*eight*positively*charged*
histone*proteins
B
M(3&/-)%"(2$)-"&%(,#44"9(NS(:#&%-#&%/(-3"(/-$6,-6$"()>("#,3(%6,4")/):"
N&/-)%"/(3"42([@M(5&%9(-)(:#7"(3&'3"$()$9"$(/-$6,-6$"/(5&-3&%(-3"(,"44
○
B
Z3$):#-&%(:6/-(*"(9$#/-&,#448($":)9"4"9(#$)6%9(#(-#$'"-('"%"(-)(#44)5(-$#%/,$&2-&)%;
NS(3&/-)%"/(#4/)(:#8(&%-"$#,-(5&-3("#,3()-3"$(#%9(5&-3(3&/-)%"/(&%()-3"$(
%6,4")/):"/(-)(>)$:(#(-&'3-48(2#,7"9(/-$6,-6$"(,#44"9(#(TgO%#%):"-"$(>&*"$;
B
?3"/"(TgO%#%):"-"$(>&*"$/(&%(-6$%(:#8(>)$:(3&'3"$O)$9"$(/-$6,-6$"/;(
Z3$):#-&%f/(/-$6,-6$"(24#8/(#(7"8($)4"(&%($"'64#-&%'('"%"("12$"//&)%;
!))2(/-$6,-6$"/(-)'"-3"$(-)(>)$:(-3"(3&'348(,):2#,-(,3$):)/):"
○
B
?)(-"/-(>)$()2"%&%'()>(,3$):#-&%()%48(&%(#$"#/(5&-3(-$#%/,$&2-&)%#448(#,-&."(
'"%"/=(5"(,#%(&/)4#-"(,3$):#-&%(>$):($"9(*4))9(,"44/(#%9(-$"#-(5&-3([@M/"
B
[@M(&/(,):2#,-"9()$(%)-(,):2#,-"9
!"//(,):2#,-(#$"#/(#$"(-$#%/,$&*"9(#%9(6/"9(-)(:#7"(:W@M
○
P2"%(,3$):#-&%(&/(-$#%/,$&2-&)%#448(#,-&."
○
Z4)/"9(,3$):#-&%(&/(/&4"%-(
○
B
[@M/"(*$"#7/(62([@M(&%(-3"(/)46-&)%
C&44()%48(,6-()2"%(,3$):#-&%
○
C&44(%)-(9"'$#9"(,4)/"9=(,)%9"%/"9(,3$):#-&%
○
B
N&/-)%"(9"#,"-84#/"/(RN[MZ/U($":)."(#,"-84('$)62/(>$):(3&/-)%"/(#%9(#44)5(
,3$):#-&%(,)%9"%/#-&)%;(#%9(&/(#//),&#-"9(5&-3('"%"(9"#,-&.#-&)%;
B
N&/-)%"(#,"-84(-$#%/>"$#/"/(RNM?/U(#99(%"'#-&."48(,3#$'"9(#,"-84('$)62/(-)(
2)/&-&."48(,3#$'"9(3&/-)%"(48/&%"($"/&96"/($"/64-&%'(&%(,3$):#-&%(
9",)%9"%/#-&)%(#%9(#44)5&%'('"%"("12$"//&)%;
B
Z3":&,#4(:)9&>&,#-&)%/()%(3&/-)%"/(.#$&"/(*"-5""%(,"44(-82"/(#%9(&/(3"$&-#*4";(
M,"-84#-&)%(&/(#%(";';()>("2&'"%"-&,(&%3"$&-#%,"=(&%3"$&-#%,"(%)-(96"(-)(
9&>>"$"%,"/(&%('"%"(/"\6"%,"/;
B
`;(H)44)5&%'([@M/"(-$"#-:"%-()>($"9(*4))9(,"44(,3$):#-&%=(,)649(8)6(/-&44(9"-",-(-3"(
2$"/"%,"()>(*O'4)*&%=(#($"9(*4))9(,"44O/2",&>&,( '"%"d(RN6:#%([@M(9)"/%f-(3#."(%6,4"&=(
3#."(-)(6/"(,3&,7"%/U
MU(e"/(
B)*No*
LO'4)*&%(&/("12",-"9(-)(*"(&%()2"%(,3$):#-&%(#%9(&/(3&'348(#,-&."(&%($"9(
*4))9(,"44/
○
<>('"%"/(-$#%/,$&2-&)%#448(#,-&."(#$"(&%()2"%(,3$):#-&%=(53"%(8)6(-$"#-(
[@M(>$):(-3"($"9(*4))9(,"44/()>([@M/"(-3#-(9&'"/-/()%48()2"%(,3$):#-&%=(
8)6f9("12",-([@M/"(-)(9"'$#9"(-3"(LO'4)*&%
○
ZU(@)(5#8(-)(2$"9&,-
Q;(H)44)5&%'([@M/"(-$"#-:"%-()>($"9(*4))9(,"44(,3$):#-&%=(,)649(8)6(/-&44(9"-",-(-3"(
2$"/"%,"()>().#4*6:&%=(#('"%"(%)-("12$"//"9(&%($"9(*4))9(,"44/d(
A)*Yes*
@)-("12$"//"9(&%(-3"/"(,"44/=(*6-(&%()-3"$(,"44/(
○
E&4"%-(5&-3&%($"9(*4))9(,"44/
○
C)649(*"(&%(3&'348(,)%9"%/"9(,4)/"9(,3$):#-&%(6%#>>",-"9(*8([@M/"(
-$"#-:"%-
○
LU(@)(
ZU(@)(5#8(-)(2$"9&,-
3.#Transcription#is#controlled#by#the#interaction#of#regulatory#proteins#with#variable#
regulatory#elements.#
P-3"$(.#$&#*4"($"'64#-)$8(9):#&%/(>)$(-$#%/,$&2-&)%()>(W@M(R/-"2(]UB
?3"(4"//(#,,"//&*4"(-3"($"'64#-)$8("4":"%-/(#$"(-)(-3"(2$)-"&%/(-3#-(%""9(-)(
*&%9(-)(-3":=(-3"(4"//(4&7"48(&-(&/(-)("12$"//(#('&."%('"%"
B
M44("67#$8)-&,('"%"/(3#."(#(,)::)%(2$):)-"$(#%9(.#$&#*4"($"'64#-)$8("4":"%-/;
M44("67#$8)-&,(promoters #$"(*)6%9(*8(-3"(TATA-binding*protein*(TBP) #-(-3"(
?M?M(*)1;(
B
?3"(promoter ),,6$/(#-(-3"(*"'&%%&%'()>(-3"('"%"(#%9(&/(-3"(/&-"(53"$"(W@M(
2)48:"$#/"(*"'&%/(-$#%/,$&2-&)%;
B
^$):)-"$O2$)1&:#4("4":"%-/(#$"(4),#-"9(+6/-(62/-$"#:()>(-3"(2$):)-"$(#%9(-3"(
-$#%/,$&2-&)%(/-#$-(/&-"(#%9(3#."(/"\6"%,"/(6%&\6"(-)(/2",&>&,('"%"/
B
A67#$8)-&,('"%"/(3#."("%3#%,"$/=(2)/&-&."($"'64#-)$8(,)%-$)4("4":"%-/;
Enhancers ,#%(*"(4),#-"9(:)$"(-3#%(Sgg=ggg(*#/"/(#5#8(>$):(-3"(2$):)-"$=(&%(
&%-$)%/=()$(&%(6%-$#%/,$&*"9(`f()$(Tf(>4#%7&%'(/"\6"%,"/;(
[&>>"$"%-("%3#%,"$/(#$"(#//),&#-"9(5&-3(9&>>"$"%-('"%"/;(
○
Activator 2$)-"&%/(*&%9("%3#%,"$/(#%9(/-$)%'48(/-&:64#-"(-3"(
-$#%/,$&2-&)%(,):24"1
○
B
Silencers=(%"'#-&."(,)%-$)4("4":"%-/=($"2$"//($#-3"$(-3#%(#,-&.#-"('"%"(
"12$"//&)%;(
E&4"%,"$/(*&%9(2$)-"&%/(,#44"9($"2$"//)$/(#%9(-6$%()>>(-$#%/,$&2-&)%_-3"8(
3#."(-3"()22)/&-"(">>",-()>("%3#%,"$/;(
○
B
Eukaryotic+Gene+Regulation+I
C"9%"/9#8=( M2$&4(Sh=(]gSh
SSY`h(MD
!"#$%&%'()*+",-&."/
1)#Describe#the#general#mechanisms#of#eukaryotic#gene#regulation#within#and#
outside#the#nucleus.#
2)#Test#the#role#of#chromatin#remodeling#in#transcriptionally#active#areas#of#the#
genome#using#the#enzyme#DNAase.#
3)#Describe#the#common#promoter#and#variable#regulatory#elements#of#
eukaryotic#genes
0"%"("12$"//&)%(,3#%'"/(#44)5("67#$8)-&,(,"44/( -)($"/2)%9(-)("%.&$)%:"%-#4(,3#%'"/(
#%9(,#6/"(9&/-&%,-(,"44( -82"/(-)(9"."4)2;(
<%(:64-&,"4464#$("67#$8)-"/=(9&>>"$"%-('"%"("12$"//&)%(&/($"/2)%/&*4"(>)$(
,$"#-&%'(9&>>"$"%-(,"44( -82"/=(#$$#%'&%'(-3":(&%-)(-&//6"/=(#%9(,))$9&%#-&%'(-3"&$(
#,-&.&-8
?)(-6$%()%(#('"%"(#-(#(-&:"(#%9(24#,"
○
@""9"9(-)($"'64#-"(9"."4)2:"%-
A$$)$/(4"#9(-)(2#-3)238/&)4)'8
§
○
B
C3#-(&-(-#7"/(>)$(#(9&24)&9(2$",6$/)$(,"44(-)(9"."4)2(&%-)(#%()$'#%&/:
D"&)/&/(4"#9/(-)('"%"-&,#448(9&/-&%,-(,"44/
E2"$:(F("''(G(%"5(9&24)&9(,"44(#%9(&%9&.&96#4(&%(%"1-('"%"$#-&)%(>)$(
)$'#%&/:
§
○
B
C&-3(>"5("1,"2-&)%/=(#44(,"44/(&%(#%()$'#%&/:(3#."(-3"(/#:"('"%"/=(*6-(-3"8("12$"//(
-3":(9&>>"$"%-48;(
H)$("1#:24"=(*)-3(*$#&%(#%9(4&."$(,"44/(-$#%/,$&*"(I3)6/"7""2&%'J('"%"/(-3#-(
,)9"(>)$("%K8:"/(#%9()-3"$(:)4",64"/("//"%-(-)(-3"(/6$.&.#4()>(#44(,"44/;(
A12$"//"9(&%(*)-3(,"44( -82"/
L)-3(,"44/(%""9(:"-#*)4&/:(>)$("%"$'8
§
○
M$"(%)-(/2",&>&,(-)(2#$-&,64#$(,"44(-82"/
○
B
N)5"."$=(4&."$(,"44/(-$#%/,$&*"(/):"('"%"/(>)$(4&."$O/2",&>&,(2$)-"&%/=(#%9(*$#&%(
,"44/(-$#%/,$&*"(/):"('"%"/(>)$(*$#&%O/2",&>&,(2$)-"&%/;(
P%48("12$"//"9(&%(,"$-#&%(24#,"/
○
L$#&%(,"44/( >)$(%"6$)%/(-)(,)%96,-(&-/(#,-&.&-&"/
○
B
?3"(9&>>"$"%,"(&%(-3"(2$)96,-&)%()>(2$)-"&%/(&/(96"(-)(differential*gene*
expression;
B
1.#Control#of#Gene#Expression#in#Eukaryotes
P."$.&"5()>(Q('"%"$#4(4"."4/(-)($"'64#-"(&>(#('"%"(&/(#,-&."(&%(#("67#$8)-&,(,"44
B
E):"(3#22"%(&%(-3"(%6,4"6/(RSOTU(#%9(/):"(&%(,8-)24#/:(RVOQU
B
W"'64#-&)%()>("67#$8)-&,('"%"(&/(:)$"(,):24"1(*",#6/"(2$)7#$8)-&,('"%"/(9)%X-(
3#."(%6,4"&
B
P."$.&"5()>('"%"($"'64#-&)%Y(
A67#$8)-&,('"%"("12$"//&)%(,#%(*"($"'64#-"9(#-(T(/-"2/(within*the*nucleus
Z3$):#-&%($":)9"4&%'Y([@M(&/(2#,7#'"9(5&-3(2$)-"&%/(&%-)(,):24"1(
/-$6,-6$"/(-3#-(:6/-(*"()2"%"9(>)$(-$#%/,$&2-&)%(-)(),,6$;
S;
?$#%/,$&2-&)%#4($"'64#-&)%Y(?$#%/,$&2-&)%(,#%(*"(&%&-&#-"9()%48(53"%(
/2",&>&,(2$)-"&%/(*&%9(-)(-3"(2$):)-"$(#%9(-)(/2",&>&,($"'64#-)$8(
/"\6"%,"/;
<%()2"%([@M(R4"//(,):2#,-U=(-3"$"(#$"($"'64#-)$8(9):#&%/(5&-3&%(
-3"([@M(-3#-(9"-"$:&%"(53"-3"$(#('"%"(5&44(*"("12$"//"9
§
A1Y(2$):)-"$Y($"'64#-"(53#-('"-/(-$#%/,$&*"9
§
M4/)($"'64#-)$8([@M(/"\6"%,"/(%""9"9(-)(9$&."("12$"//&)%
§
];
M4-"$%#-&."(/24&,&%'(#44)5/(#(/&%'4"('"%"(-)(,)9"(>)$(/"."$#4(9&>>"$"%-(
2$)96,-/;
^$),"//&%'(W@M
§
,[@M/(>$):(:W@M
§
W@M(&/(2$),"//"9(&/(#(-3&$9(5#8()>($"'64#-&%'("67#$8)-&,('"%"/
§
T;
B
A67#$8)-&,('"%"("12$"//&)%(,#%(*"(>6$-3"$($"'64#-"9(#-(T(/-"2/(within*the*
cytoplasm;
B
P%,"(#%(:W@M(&/(&%(-3"(,8-)24#/:=('"%"("12$"//&)%(&/(,)%-$)44"9(*8(:)4",64"/(
-3#-($"'64#-"(-3"(>)44)5&%'Y
?3"(4&>"(/2#%()>(:W@M/V;
?3"(">>&,&"%,8()>(-$#%/4#-&)%_-)(-$#%/4#-"()$(%)-(-)(-$#%/4#-"
Z#%(,3":&,#448(:)9&>8($&*)/):"/(-)(,3#%'"($#-"/()>(-$#%/4#-&)%
§
`;
?3"(#,-&.#-&)%()$(&%#,-&.#-&)%()>(2$)-"&%(2$)96,-/
Z"44(/&'%#4&%'
§
^3)/23)$84#-&)%(&/(#(2)/-O-$#%/4#-&)%#4(:)9&>&,#-&)%
§
Q;
1. ?3"(/&%'4"=(6%&."$/#4($"'64#-)$8(:",3#%&/:(&%("67#$8)-"/(>)$(,)%-$)44&%'('"%"(
"12$"//&)%(&%,469"/Y(
MU(,)%-$)4()>(-3"('"%"/(-$#%/,$&*"9(#%9(-3"($#-"(-3"8(#$"(-$#%/,$&*"9;(
LU(,)%-$)4()>(-3"(2$),"//&%'()>(:W@M(#>-"$(&-(&/(-$#%/,$&*"9(>$):([@M;(
ZU(,)%-$)4()>(:W@M(&%(-3"(,8-)24#/:(#>-"$(&-(4"#."/(-3"(%6,4"6/=(&%,469&%'(
,3#%'"/(-)(:W@M(*">)$"(-$#%/4#-&)%(*"'&%/;(
[U(,)%-$)4()>(2)482"2-&9"/(#>-"$(-3"8(3#."(*""%(/8%-3"/&K"9(*6-(*">)$"(-3"8(#$"(
>6%,-&)%#4;(
E)*All*of*these*mechanisms*are*used;*there*is*no*single*universal*mechanism.*
A67#$8)-&,('"%"($"'64#-&)%(&/(,):24"1
○
W"'64#-&)%(),,6$/(#-(#(.#$&"-8()>(4"."4/(&%(-3"(%6,4"6/(#%9(,8-)24#/:
○
2.#Chromatin#remodeling#is#required#prior#to#gene#transcription.
W"'64#-&%'(9"'$""()>(,):2#,-&)%()>([@M(#$)6%9(2$)-"&%(a,3$):#-&%B
Z3$):#-&%($":)9"4&%'(a3)5(-&'3-48(5"(5&%9([@M(#$)6%9(2$)-"&%
?3"(:)$"(-&'3-48(8)6(5&%9([@M=(-3"(4"//(#,,"//&*4"( $"'64#-)$8([@M(
$"'&)%/(#$"(-)(2#$-%"$&%'(2$)-"&%/(4&7"(W@M(2)48:"$#/"
W@M(2)48:"$#/"(%""9/(-)(*&%9(-)(#(2$):)-"$(-)(7%)5(53"$"(-)(
*&%9(>)$(-$#%/,$&2-&)%
§
?&'3-(5&%9&%'(,#%(:#7"(2$):)-"$(&%#,,"//&*4"
§
○
B
?5)(9&>>"$"%-(7&%9/()>(,3$):#-&%(,#%(*"(9&/-&%'6&/3"9(*8(/-#&%&%'(-3"(%6,4"6/;(
Euchromatin /-#&%/(4&'3-48
It*contains*DNA*that*is*transcribed*into*mRNA
Transcriptionally*active*DNAb
§
[@M(&/(%)-(5)6%9(."$8(-&'3-48(a4))/"(,)%>&'6$#-&)%
?3&/($"'&)%()>(-3"(,3$):)/):"(3#/(4))/"(,3$):#-&%b
§
@)-(#(4)-(&%()%"(/2)-(-)(2&,7(62(#(4)-()>(98"
§
○
Heterochromatin /-#&%/(9"%/"48(#%9(&/('"%"$#448(%)-(-$#%/,$&*"9;(
Any*genes*in*heterochromatin*are*thus*inactivated.
Largely*silent*DNAb
§
?&'3-48(5)6%9=(3&'348(,)%9"%/"9
§
[8"(&/(#*/)$*"9(-)(#('$"#-"$(9"'$""(-)(/-#&%(9#$7"$
§
○
B
N"-"$),3$):#-&%(&/(&%(>)6%9(&%(-3"(&%#,-&."(c(,3$):)/):"()>(:#::#4/;
P%"()>(-3"(c(,3$):)/):"/(&%("#,3(,"44( )>(#(>":#4"(&/(&%#,-&.#-"9(*8([@M(
:"-384#-&)% "#$48(&%(9"."4)2:"%-;
Z)649("12$"//(-5&,"(#/(:6,3(&%(c()>(:#4"=()$(3#4>()>(cc(&%(>":#4"
○
<%(>":#4"/=()%"()>(-3"(c(,3$):)/):"/
○
P%"(c(&/(3&'348(:"-384#-"9(#%9(4"#9/(-)(c(,3$):)/):"(/&4"%,&%'
○
B
?3"(,3$):)/):"($":#&%/(,)%9"%/"9(#%9(#22"#$/(#/(#(Barr*body 6%9"$(-3"(
:&,$)/,)2";(
Condensation*physically*prevents*DNA*from*being*transcribed
○
L#$$(*)98(-#7"/(62(#(4)-()>(/-#&%=(/)(#22"#$/(9#$7
○
?3#-(&/(#(/&4"%,"9(c(,3$):)/):"
○
E&4"%,"9(c(,3$):)/):"(,3#%'"/(>$):(,"44(-)(,"44
<>(-3"$"(&/(#(9&/"#/"=(&/("12$"//"9(3#4>(-3"(-&:"
§
○
B
2. M(>)$:()>(-$#%/,$&2-&)%#448(#,-&."(,3$):#-&%(&/($">"$$"9(-)(#/Y(
MU(#(L#$$(*)98;(
LU(3"-"$),3$):#-&%;(
ZU(#(,3$):)/):";(
D)*euchromatin.*
AU(@)%"()>(-3"/"
?3"(2#-"$%#448(#%9(:#-"$%#448O&%3"$&-"9(cO,3$):)/):"/(#$"('"%"$#448(/36-(9)5%(5&-3(
"\6#4(2$)*#*&4&-8;(
C3#-(&/(-3"('"%"-&,(,)%/"\6"%,"()>(-3&/($#%9):(cO,3$):)/):"(&%#,-&.#-&)%d(B
M44(3"-"$)K8')-"/(>)$(#(2#$-&,64#$(cO4&%7"9(-$#&-(5&44("13&*&-(mosaicism;(
<%(#(:)/#&,=(8)6(3#."(/):"(,"44/(-3#-(3#."(#('&."%(23"%)-82"(#%9()-3"$(
,"44/(5&-3(#%)-3"$(23"%)-82"
○
B
?3"(-)$-)&/"/3"44(,#-(&/(#(,)::)%("1#:24";(C3&4"(:64-&24"('"%"/(,)%-$&*6-"(-)(
>"4&%"(,)#-(,)4)$=(-3"('"%"($"/2)%/&*4"(>)$(-3&/(23"%)-82"(&/(cO4&%7"9=(#%9(3#/(#%(
)$#%'"(#%9(#(*4#,7(#44"4"
?82&,#448(>":#4"
○
N#."(-)(*"(3"-"$)K8')6/
L4#,7(2#-,3"/(>)$:(96"(-)(&%#,-&.#-&)%()>()-3"$(,3$):)/):"(5&-3(
-3"()$#%'"(#44"4"
§
?3"()$#%'"(2#-,3"/(#$"()$#%'"(*",#6/"(-3"(,3$):)/):"(5&-3(-3"(
*4#,7(,)4)$#-&)%(#44"4"(')-(/&4"%,"9
§
○
^#-,3"/(9&>>"$(*",#6/"()>(9"#,-&.#-&)%($#%9):48()>(,3$):)/):"/
○
B
3. Z#%(#(-)$-)&/"/3"44(,#-(*"(:#4"d(
MU(e"/=(#44(,#-/()>(-3&/(23"%)-82"(#$"(:#4";(
LU(@)=(&-(&/(%)-(2)//&*4"(>)$(:#4"(,#-/(-)(3#."(-3"(-)$-)&/"/3"44(23"%)-82";(
C)*Yes,*in*rare*circumstances,*tortoiseshell*males*cats*are*possible.*
W"/64-/(>$):(%)%9&/+6%,-&)%(#%9(3#."(#%(cce(:#4"
○
E&4"%,&%'()>(cf/(,#%(),,6$
○
[U(e"/=(*)-3(:#4"/(#%9(>":#4"/(#$"("\6#448(4&7"48(-)(*"(-)$-)&/"/3"44;
4. C3&,3()>(-3"(>)44)5&%'(/-#-":"%-/($"'#$9&%'(c(&%#,-&.#-&)%(&%(:#::#4/(&/(HM!EAd(
MU(?3"(2$),"//(&/("%-&$"48($#%9):;(
LU(c(&%#,-&.#-&)%(:#8(),,#/&)%#448(),,6$(&%(:#4"/;(
C)*This*process*ensures*a*homogenous*phenotype*in*heterozygotes.
[)"/%f-(9"/,$&*"("1#:24"()>(-)$-&)6/(/3"44(,#-
○
[U(c(&%#,-&.#-&)%(),,6$/("#$48(&%(":*$8)%&,(9"."4)2:"%-;
?3"("4#*)$#-"(/-$6,-6$"()>(,3$):#-&%(#44)5/([@M(-)(*"(2#,7#'"9(&%(-3"(%6,4"6/;
Chromatin*contains*nucleosomes,*repeating,*beadlike*structures*that*consist*
of*negatively*charged*DNA*wrapped*twice*around*eight*positively*charged*
histone*proteins
B
M(3&/-)%"(2$)-"&%(,#44"9(NS(:#&%-#&%/(-3"(/-$6,-6$"()>("#,3(%6,4")/):"
N&/-)%"/(3"42([@M(5&%9(-)(:#7"(3&'3"$()$9"$(/-$6,-6$"/(5&-3&%(-3"(,"44
○
B
Z3$):#-&%(:6/-(*"(9$#/-&,#448($":)9"4"9(#$)6%9(#(-#$'"-('"%"(-)(#44)5(-$#%/,$&2-&)%;
NS(3&/-)%"/(#4/)(:#8(&%-"$#,-(5&-3("#,3()-3"$(#%9(5&-3(3&/-)%"/(&%()-3"$(
%6,4")/):"/(-)(>)$:(#(-&'3-48(2#,7"9(/-$6,-6$"(,#44"9(#(TgO%#%):"-"$(>&*"$;
B
?3"/"(TgO%#%):"-"$(>&*"$/(&%(-6$%(:#8(>)$:(3&'3"$O)$9"$(/-$6,-6$"/;(
Z3$):#-&%f/(/-$6,-6$"(24#8/(#(7"8($)4"(&%($"'64#-&%'('"%"("12$"//&)%;
!))2(/-$6,-6$"/(-)'"-3"$(-)(>)$:(-3"(3&'348(,):2#,-(,3$):)/):"
○
B
?)(-"/-(>)$()2"%&%'()>(,3$):#-&%()%48(&%(#$"#/(5&-3(-$#%/,$&2-&)%#448(#,-&."(
'"%"/=(5"(,#%(&/)4#-"(,3$):#-&%(>$):($"9(*4))9(,"44/(#%9(-$"#-(5&-3([@M/"
B
[@M(&/(,):2#,-"9()$(%)-(,):2#,-"9
!"//(,):2#,-(#$"#/(#$"(-$#%/,$&*"9(#%9(6/"9(-)(:#7"(:W@M
○
P2"%(,3$):#-&%(&/(-$#%/,$&2-&)%#448(#,-&."
○
Z4)/"9(,3$):#-&%(&/(/&4"%-(
○
B
[@M/"(*$"#7/(62([@M(&%(-3"(/)46-&)%
C&44()%48(,6-()2"%(,3$):#-&%
○
C&44(%)-(9"'$#9"(,4)/"9=(,)%9"%/"9(,3$):#-&%
○
B
N&/-)%"(9"#,"-84#/"/(RN[MZ/U($":)."(#,"-84('$)62/(>$):(3&/-)%"/(#%9(#44)5(
,3$):#-&%(,)%9"%/#-&)%;(#%9(&/(#//),&#-"9(5&-3('"%"(9"#,-&.#-&)%;
B
N&/-)%"(#,"-84(-$#%/>"$#/"/(RNM?/U(#99(%"'#-&."48(,3#$'"9(#,"-84('$)62/(-)(
2)/&-&."48(,3#$'"9(3&/-)%"(48/&%"($"/&96"/($"/64-&%'(&%(,3$):#-&%(
9",)%9"%/#-&)%(#%9(#44)5&%'('"%"("12$"//&)%;
B
Z3":&,#4(:)9&>&,#-&)%/()%(3&/-)%"/(.#$&"/(*"-5""%(,"44(-82"/(#%9(&/(3"$&-#*4";(
M,"-84#-&)%(&/(#%(";';()>("2&'"%"-&,(&%3"$&-#%,"=(&%3"$&-#%,"(%)-(96"(-)(
9&>>"$"%,"/(&%('"%"(/"\6"%,"/;
B
`;(H)44)5&%'([@M/"(-$"#-:"%-()>($"9(*4))9(,"44(,3$):#-&%=(,)649(8)6(/-&44(9"-",-(-3"(
2$"/"%,"()>(*O'4)*&%=(#($"9(*4))9(,"44O/2",&>&,( '"%"d(RN6:#%([@M(9)"/%f-(3#."(%6,4"&=(
3#."(-)(6/"(,3&,7"%/U
MU(e"/(
B)*No*
LO'4)*&%(&/("12",-"9(-)(*"(&%()2"%(,3$):#-&%(#%9(&/(3&'348(#,-&."(&%($"9(
*4))9(,"44/
○
<>('"%"/(-$#%/,$&2-&)%#448(#,-&."(#$"(&%()2"%(,3$):#-&%=(53"%(8)6(-$"#-(
[@M(>$):(-3"($"9(*4))9(,"44/()>([@M/"(-3#-(9&'"/-/()%48()2"%(,3$):#-&%=(
8)6f9("12",-([@M/"(-)(9"'$#9"(-3"(LO'4)*&%
○
ZU(@)(5#8(-)(2$"9&,-
Q;(H)44)5&%'([@M/"(-$"#-:"%-()>($"9(*4))9(,"44(,3$):#-&%=(,)649(8)6(/-&44(9"-",-(-3"(
2$"/"%,"()>().#4*6:&%=(#('"%"(%)-("12$"//"9(&%($"9(*4))9(,"44/d(
A)*Yes*
@)-("12$"//"9(&%(-3"/"(,"44/=(*6-(&%()-3"$(,"44/(
○
E&4"%-(5&-3&%($"9(*4))9(,"44/
○
C)649(*"(&%(3&'348(,)%9"%/"9(,4)/"9(,3$):#-&%(6%#>>",-"9(*8([@M/"(
-$"#-:"%-
○
LU(@)(
ZU(@)(5#8(-)(2$"9&,-
3.#Transcription#is#controlled#by#the#interaction#of#regulatory#proteins#with#variable#
regulatory#elements.#
P-3"$(.#$&#*4"($"'64#-)$8(9):#&%/(>)$(-$#%/,$&2-&)%()>(W@M(R/-"2(]UB
?3"(4"//(#,,"//&*4"(-3"($"'64#-)$8("4":"%-/(#$"(-)(-3"(2$)-"&%/(-3#-(%""9(-)(
*&%9(-)(-3":=(-3"(4"//(4&7"48(&-(&/(-)("12$"//(#('&."%('"%"
B
M44("67#$8)-&,('"%"/(3#."(#(,)::)%(2$):)-"$(#%9(.#$&#*4"($"'64#-)$8("4":"%-/;
M44("67#$8)-&,(promoters #$"(*)6%9(*8(-3"(TATA-binding*protein*(TBP) #-(-3"(
?M?M(*)1;(
B
?3"(promoter ),,6$/(#-(-3"(*"'&%%&%'()>(-3"('"%"(#%9(&/(-3"(/&-"(53"$"(W@M(
2)48:"$#/"(*"'&%/(-$#%/,$&2-&)%;
B
^$):)-"$O2$)1&:#4("4":"%-/(#$"(4),#-"9(+6/-(62/-$"#:()>(-3"(2$):)-"$(#%9(-3"(
-$#%/,$&2-&)%(/-#$-(/&-"(#%9(3#."(/"\6"%,"/(6%&\6"(-)(/2",&>&,('"%"/
B
A67#$8)-&,('"%"/(3#."("%3#%,"$/=(2)/&-&."($"'64#-)$8(,)%-$)4("4":"%-/;
Enhancers ,#%(*"(4),#-"9(:)$"(-3#%(Sgg=ggg(*#/"/(#5#8(>$):(-3"(2$):)-"$=(&%(
&%-$)%/=()$(&%(6%-$#%/,$&*"9(`f()$(Tf(>4#%7&%'(/"\6"%,"/;(
[&>>"$"%-("%3#%,"$/(#$"(#//),&#-"9(5&-3(9&>>"$"%-('"%"/;(
○
Activator 2$)-"&%/(*&%9("%3#%,"$/(#%9(/-$)%'48(/-&:64#-"(-3"(
-$#%/,$&2-&)%(,):24"1
○
B
Silencers=(%"'#-&."(,)%-$)4("4":"%-/=($"2$"//($#-3"$(-3#%(#,-&.#-"('"%"(
"12$"//&)%;(
E&4"%,"$/(*&%9(2$)-"&%/(,#44"9($"2$"//)$/(#%9(-6$%()>>(-$#%/,$&2-&)%_-3"8(
3#."(-3"()22)/&-"(">>",-()>("%3#%,"$/;(
○
B
Eukaryotic+Gene+Regulation+I
C"9%"/9#8=( M2$&4(Sh=(]gSh SSY`h(MD
!"#$%&%'()*+",-&."/
1)#Describe#the#general#mechanisms#of#eukaryotic#gene#regulation#within#and#
outside#the#nucleus.#
2)#Test#the#role#of#chromatin#remodeling#in#transcriptionally#active#areas#of#the#
genome#using#the#enzyme#DNAase.#
3)#Describe#the#common#promoter#and#variable#regulatory#elements#of#
eukaryotic#genes
0"%"("12$"//&)%(,3#%'"/(#44)5("67#$8)-&,(,"44/( -)($"/2)%9(-)("%.&$)%:"%-#4(,3#%'"/(
#%9(,#6/"(9&/-&%,-(,"44( -82"/(-)(9"."4)2;(
<%(:64-&,"4464#$("67#$8)-"/=(9&>>"$"%-('"%"("12$"//&)%(&/($"/2)%/&*4"(>)$(
,$"#-&%'(9&>>"$"%-(,"44( -82"/=(#$$#%'&%'(-3":(&%-)(-&//6"/=(#%9(,))$9&%#-&%'(-3"&$(
#,-&.&-8
?)(-6$%()%(#('"%"(#-(#(-&:"(#%9(24#,"
○
@""9"9(-)($"'64#-"(9"."4)2:"%-
A$$)$/(4"#9(-)(2#-3)238/&)4)'8
§
○
B
C3#-(&-(-#7"/(>)$(#(9&24)&9(2$",6$/)$(,"44(-)(9"."4)2(&%-)(#%()$'#%&/:
D"&)/&/(4"#9/(-)('"%"-&,#448(9&/-&%,-(,"44/
E2"$:(F("''(G(%"5(9&24)&9(,"44(#%9(&%9&.&96#4(&%(%"1-('"%"$#-&)%(>)$(
)$'#%&/:
§
○
B
C&-3(>"5("1,"2-&)%/=(#44(,"44/(&%(#%()$'#%&/:(3#."(-3"(/#:"('"%"/=(*6-(-3"8("12$"//(
-3":(9&>>"$"%-48;(
H)$("1#:24"=(*)-3(*$#&%(#%9(4&."$(,"44/(-$#%/,$&*"(I3)6/"7""2&%'J('"%"/(-3#-(
,)9"(>)$("%K8:"/(#%9()-3"$(:)4",64"/("//"%-(-)(-3"(/6$.&.#4()>(#44(,"44/;(
A12$"//"9(&%(*)-3(,"44( -82"/
L)-3(,"44/(%""9(:"-#*)4&/:(>)$("%"$'8
§
○
M$"(%)-(/2",&>&,(-)(2#$-&,64#$(,"44(-82"/
○
B
N)5"."$=(4&."$(,"44/(-$#%/,$&*"(/):"('"%"/(>)$(4&."$O/2",&>&,(2$)-"&%/=(#%9(*$#&%(
,"44/(-$#%/,$&*"(/):"('"%"/(>)$(*$#&%O/2",&>&,(2$)-"&%/;(
P%48("12$"//"9(&%(,"$-#&%(24#,"/
○
L$#&%(,"44/( >)$(%"6$)%/(-)(,)%96,-(&-/(#,-&.&-&"/
○
B
?3"(9&>>"$"%,"(&%(-3"(2$)96,-&)%()>(2$)-"&%/(&/(96"(-)(differential*gene*
expression;
B
1.#Control#of#Gene#Expression#in#Eukaryotes
P."$.&"5()>(Q('"%"$#4(4"."4/(-)($"'64#-"(&>(#('"%"(&/(#,-&."(&%(#("67#$8)-&,(,"44B
E):"(3#22"%(&%(-3"(%6,4"6/(RSOTU(#%9(/):"(&%(,8-)24#/:(RVOQUB
W"'64#-&)%()>("67#$8)-&,('"%"(&/(:)$"(,):24"1(*",#6/"(2$)7#$8)-&,('"%"/(9)%X-(
3#."(%6,4"&
B
P."$.&"5()>('"%"($"'64#-&)%Y(
A67#$8)-&,('"%"("12$"//&)%(,#%(*"($"'64#-"9(#-(T(/-"2/(within*the*nucleus
Z3$):#-&%($":)9"4&%'Y([@M(&/(2#,7#'"9(5&-3(2$)-"&%/(&%-)(,):24"1(
/-$6,-6$"/(-3#-(:6/-(*"()2"%"9(>)$(-$#%/,$&2-&)%(-)(),,6$;
S;
?$#%/,$&2-&)%#4($"'64#-&)%Y(?$#%/,$&2-&)%(,#%(*"(&%&-&#-"9()%48(53"%(
/2",&>&,(2$)-"&%/(*&%9(-)(-3"(2$):)-"$(#%9(-)(/2",&>&,($"'64#-)$8(
/"\6"%,"/;
<%()2"%([@M(R4"//(,):2#,-U=(-3"$"(#$"($"'64#-)$8(9):#&%/(5&-3&%(
-3"([@M(-3#-(9"-"$:&%"(53"-3"$(#('"%"(5&44(*"("12$"//"9
§
A1Y(2$):)-"$Y($"'64#-"(53#-('"-/(-$#%/,$&*"9
§
M4/)($"'64#-)$8([@M(/"\6"%,"/(%""9"9(-)(9$&."("12$"//&)%
§
];
M4-"$%#-&."(/24&,&%'(#44)5/(#(/&%'4"('"%"(-)(,)9"(>)$(/"."$#4(9&>>"$"%-(
2$)96,-/;
^$),"//&%'(W@M
§
,[@M/(>$):(:W@M
§
W@M(&/(2$),"//"9(&/(#(-3&$9(5#8()>($"'64#-&%'("67#$8)-&,('"%"/
§
T;
B
A67#$8)-&,('"%"("12$"//&)%(,#%(*"(>6$-3"$($"'64#-"9(#-(T(/-"2/(within*the*
cytoplasm;
B
P%,"(#%(:W@M(&/(&%(-3"(,8-)24#/:=('"%"("12$"//&)%(&/(,)%-$)44"9(*8(:)4",64"/(
-3#-($"'64#-"(-3"(>)44)5&%'Y
?3"(4&>"(/2#%()>(:W@M/
V;
?3"(">>&,&"%,8()>(-$#%/4#-&)%_-)(-$#%/4#-"()$(%)-(-)(-$#%/4#-"
Z#%(,3":&,#448(:)9&>8($&*)/):"/(-)(,3#%'"($#-"/()>(-$#%/4#-&)%
§
`;
?3"(#,-&.#-&)%()$(&%#,-&.#-&)%()>(2$)-"&%(2$)96,-/
Z"44(/&'%#4&%'
§
^3)/23)$84#-&)%(&/(#(2)/-O-$#%/4#-&)%#4(:)9&>&,#-&)%
§
Q;
1. ?3"(/&%'4"=(6%&."$/#4($"'64#-)$8(:",3#%&/:(&%("67#$8)-"/(>)$(,)%-$)44&%'('"%"(
"12$"//&)%(&%,469"/Y(
MU(,)%-$)4()>(-3"('"%"/(-$#%/,$&*"9(#%9(-3"($#-"(-3"8(#$"(-$#%/,$&*"9;(
LU(,)%-$)4()>(-3"(2$),"//&%'()>(:W@M(#>-"$(&-(&/(-$#%/,$&*"9(>$):([@M;(
ZU(,)%-$)4()>(:W@M(&%(-3"(,8-)24#/:(#>-"$(&-(4"#."/(-3"(%6,4"6/=(&%,469&%'(
,3#%'"/(-)(:W@M(*">)$"(-$#%/4#-&)%(*"'&%/;(
[U(,)%-$)4()>(2)482"2-&9"/(#>-"$(-3"8(3#."(*""%(/8%-3"/&K"9(*6-(*">)$"(-3"8(#$"(
>6%,-&)%#4;(
E)*All*of*these*mechanisms*are*used;*there*is*no*single*universal*mechanism.*
A67#$8)-&,('"%"($"'64#-&)%(&/(,):24"1
○
W"'64#-&)%(),,6$/(#-(#(.#$&"-8()>(4"."4/(&%(-3"(%6,4"6/(#%9(,8-)24#/:
○
2.#Chromatin#remodeling#is#required#prior#to#gene#transcription.
W"'64#-&%'(9"'$""()>(,):2#,-&)%()>([@M(#$)6%9(2$)-"&%(a,3$):#-&%
B
Z3$):#-&%($":)9"4&%'(a3)5(-&'3-48(5"(5&%9([@M(#$)6%9(2$)-"&%
?3"(:)$"(-&'3-48(8)6(5&%9([@M=(-3"(4"//(#,,"//&*4"( $"'64#-)$8([@M(
$"'&)%/(#$"(-)(2#$-%"$&%'(2$)-"&%/(4&7"(W@M(2)48:"$#/"
W@M(2)48:"$#/"(%""9/(-)(*&%9(-)(#(2$):)-"$(-)(7%)5(53"$"(-)(
*&%9(>)$(-$#%/,$&2-&)%
§
?&'3-(5&%9&%'(,#%(:#7"(2$):)-"$(&%#,,"//&*4"
§
○
B
?5)(9&>>"$"%-(7&%9/()>(,3$):#-&%(,#%(*"(9&/-&%'6&/3"9(*8(/-#&%&%'(-3"(%6,4"6/;(
Euchromatin /-#&%/(4&'3-48
It*contains*DNA*that*is*transcribed*into*mRNA
Transcriptionally*active*DNAb
§
[@M(&/(%)-(5)6%9(."$8(-&'3-48(a4))/"(,)%>&'6$#-&)%
?3&/($"'&)%()>(-3"(,3$):)/):"(3#/(4))/"(,3$):#-&%b
§
@)-(#(4)-(&%()%"(/2)-(-)(2&,7(62(#(4)-()>(98"
§
○
Heterochromatin /-#&%/(9"%/"48(#%9(&/('"%"$#448(%)-(-$#%/,$&*"9;(
Any*genes*in*heterochromatin*are*thus*inactivated.
Largely*silent*DNAb
§
?&'3-48(5)6%9=(3&'348(,)%9"%/"9
§
[8"(&/(#*/)$*"9(-)(#('$"#-"$(9"'$""(-)(/-#&%(9#$7"$
§
○
B
N"-"$),3$):#-&%(&/(&%(>)6%9(&%(-3"(&%#,-&."(c(,3$):)/):"()>(:#::#4/;
P%"()>(-3"(c(,3$):)/):"/(&%("#,3(,"44( )>(#(>":#4"(&/(&%#,-&.#-"9(*8([@M(
:"-384#-&)% "#$48(&%(9"."4)2:"%-;
Z)649("12$"//(-5&,"(#/(:6,3(&%(c()>(:#4"=()$(3#4>()>(cc(&%(>":#4"
○
<%(>":#4"/=()%"()>(-3"(c(,3$):)/):"/
○
P%"(c(&/(3&'348(:"-384#-"9(#%9(4"#9/(-)(c(,3$):)/):"(/&4"%,&%'
○
B
?3"(,3$):)/):"($":#&%/(,)%9"%/"9(#%9(#22"#$/(#/(#(Barr*body 6%9"$(-3"(
:&,$)/,)2";(
Condensation*physically*prevents*DNA*from*being*transcribed
○
L#$$(*)98(-#7"/(62(#(4)-()>(/-#&%=(/)(#22"#$/(9#$7
○
?3#-(&/(#(/&4"%,"9(c(,3$):)/):"
○
E&4"%,"9(c(,3$):)/):"(,3#%'"/(>$):(,"44(-)(,"44
<>(-3"$"(&/(#(9&/"#/"=(&/("12$"//"9(3#4>(-3"(-&:"
§
○
B
2. M(>)$:()>(-$#%/,$&2-&)%#448(#,-&."(,3$):#-&%(&/($">"$$"9(-)(#/Y(
MU(#(L#$$(*)98;(
LU(3"-"$),3$):#-&%;(
ZU(#(,3$):)/):";(
D)*euchromatin.*
AU(@)%"()>(-3"/"
?3"(2#-"$%#448(#%9(:#-"$%#448O&%3"$&-"9(cO,3$):)/):"/(#$"('"%"$#448(/36-(9)5%(5&-3(
"\6#4(2$)*#*&4&-8;(
C3#-(&/(-3"('"%"-&,(,)%/"\6"%,"()>(-3&/($#%9):(cO,3$):)/):"(&%#,-&.#-&)%d(B
M44(3"-"$)K8')-"/(>)$(#(2#$-&,64#$(cO4&%7"9(-$#&-(5&44("13&*&-(mosaicism;(
<%(#(:)/#&,=(8)6(3#."(/):"(,"44/(-3#-(3#."(#('&."%(23"%)-82"(#%9()-3"$(
,"44/(5&-3(#%)-3"$(23"%)-82"
○
B
?3"(-)$-)&/"/3"44(,#-(&/(#(,)::)%("1#:24";(C3&4"(:64-&24"('"%"/(,)%-$&*6-"(-)(
>"4&%"(,)#-(,)4)$=(-3"('"%"($"/2)%/&*4"(>)$(-3&/(23"%)-82"(&/(cO4&%7"9=(#%9(3#/(#%(
)$#%'"(#%9(#(*4#,7(#44"4"
?82&,#448(>":#4"
○
N#."(-)(*"(3"-"$)K8')6/
L4#,7(2#-,3"/(>)$:(96"(-)(&%#,-&.#-&)%()>()-3"$(,3$):)/):"(5&-3(
-3"()$#%'"(#44"4"
§
?3"()$#%'"(2#-,3"/(#$"()$#%'"(*",#6/"(-3"(,3$):)/):"(5&-3(-3"(
*4#,7(,)4)$#-&)%(#44"4"(')-(/&4"%,"9
§
○
^#-,3"/(9&>>"$(*",#6/"()>(9"#,-&.#-&)%($#%9):48()>(,3$):)/):"/
○
B
3. Z#%(#(-)$-)&/"/3"44(,#-(*"(:#4"d(
MU(e"/=(#44(,#-/()>(-3&/(23"%)-82"(#$"(:#4";(
LU(@)=(&-(&/(%)-(2)//&*4"(>)$(:#4"(,#-/(-)(3#."(-3"(-)$-)&/"/3"44(23"%)-82";(
C)*Yes,*in*rare*circumstances,*tortoiseshell*males*cats*are*possible.*
W"/64-/(>$):(%)%9&/+6%,-&)%(#%9(3#."(#%(cce(:#4"
○
E&4"%,&%'()>(cf/(,#%(),,6$
○
[U(e"/=(*)-3(:#4"/(#%9(>":#4"/(#$"("\6#448(4&7"48(-)(*"(-)$-)&/"/3"44;
4. C3&,3()>(-3"(>)44)5&%'(/-#-":"%-/($"'#$9&%'(c(&%#,-&.#-&)%(&%(:#::#4/(&/(HM!EAd(
MU(?3"(2$),"//(&/("%-&$"48($#%9):;(
LU(c(&%#,-&.#-&)%(:#8(),,#/&)%#448(),,6$(&%(:#4"/;(
C)*This*process*ensures*a*homogenous*phenotype*in*heterozygotes.
[)"/%f-(9"/,$&*"("1#:24"()>(-)$-&)6/(/3"44(,#-
○
[U(c(&%#,-&.#-&)%(),,6$/("#$48(&%(":*$8)%&,(9"."4)2:"%-;
?3"("4#*)$#-"(/-$6,-6$"()>(,3$):#-&%(#44)5/([@M(-)(*"(2#,7#'"9(&%(-3"(%6,4"6/;
Chromatin*contains*nucleosomes,*repeating,*beadlike*structures*that*consist*
of*negatively*charged*DNA*wrapped*twice*around*eight*positively*charged*
histone*proteins
B
M(3&/-)%"(2$)-"&%(,#44"9(NS(:#&%-#&%/(-3"(/-$6,-6$"()>("#,3(%6,4")/):"
N&/-)%"/(3"42([@M(5&%9(-)(:#7"(3&'3"$()$9"$(/-$6,-6$"/(5&-3&%(-3"(,"44
○
B
Z3$):#-&%(:6/-(*"(9$#/-&,#448($":)9"4"9(#$)6%9(#(-#$'"-('"%"(-)(#44)5(-$#%/,$&2-&)%;
NS(3&/-)%"/(#4/)(:#8(&%-"$#,-(5&-3("#,3()-3"$(#%9(5&-3(3&/-)%"/(&%()-3"$(
%6,4")/):"/(-)(>)$:(#(-&'3-48(2#,7"9(/-$6,-6$"(,#44"9(#(TgO%#%):"-"$(>&*"$;
B
?3"/"(TgO%#%):"-"$(>&*"$/(&%(-6$%(:#8(>)$:(3&'3"$O)$9"$(/-$6,-6$"/;(
Z3$):#-&%f/(/-$6,-6$"(24#8/(#(7"8($)4"(&%($"'64#-&%'('"%"("12$"//&)%;
!))2(/-$6,-6$"/(-)'"-3"$(-)(>)$:(-3"(3&'348(,):2#,-(,3$):)/):"
○
B
?)(-"/-(>)$()2"%&%'()>(,3$):#-&%()%48(&%(#$"#/(5&-3(-$#%/,$&2-&)%#448(#,-&."(
'"%"/=(5"(,#%(&/)4#-"(,3$):#-&%(>$):($"9(*4))9(,"44/(#%9(-$"#-(5&-3([@M/"
B
[@M(&/(,):2#,-"9()$(%)-(,):2#,-"9
!"//(,):2#,-(#$"#/(#$"(-$#%/,$&*"9(#%9(6/"9(-)(:#7"(:W@M
○
P2"%(,3$):#-&%(&/(-$#%/,$&2-&)%#448(#,-&."
○
Z4)/"9(,3$):#-&%(&/(/&4"%-(
○
B
[@M/"(*$"#7/(62([@M(&%(-3"(/)46-&)%
C&44()%48(,6-()2"%(,3$):#-&%
○
C&44(%)-(9"'$#9"(,4)/"9=(,)%9"%/"9(,3$):#-&%
○
B
N&/-)%"(9"#,"-84#/"/(RN[MZ/U($":)."(#,"-84('$)62/(>$):(3&/-)%"/(#%9(#44)5(
,3$):#-&%(,)%9"%/#-&)%;(#%9(&/(#//),&#-"9(5&-3('"%"(9"#,-&.#-&)%;
B
N&/-)%"(#,"-84(-$#%/>"$#/"/(RNM?/U(#99(%"'#-&."48(,3#$'"9(#,"-84('$)62/(-)(
2)/&-&."48(,3#$'"9(3&/-)%"(48/&%"($"/&96"/($"/64-&%'(&%(,3$):#-&%(
9",)%9"%/#-&)%(#%9(#44)5&%'('"%"("12$"//&)%;
B
Z3":&,#4(:)9&>&,#-&)%/()%(3&/-)%"/(.#$&"/(*"-5""%(,"44(-82"/(#%9(&/(3"$&-#*4";(
M,"-84#-&)%(&/(#%(";';()>("2&'"%"-&,(&%3"$&-#%,"=(&%3"$&-#%,"(%)-(96"(-)(
9&>>"$"%,"/(&%('"%"(/"\6"%,"/;
B
`;(H)44)5&%'([@M/"(-$"#-:"%-()>($"9(*4))9(,"44(,3$):#-&%=(,)649(8)6(/-&44(9"-",-(-3"(
2$"/"%,"()>(*O'4)*&%=(#($"9(*4))9(,"44O/2",&>&,( '"%"d(RN6:#%([@M(9)"/%f-(3#."(%6,4"&=(
3#."(-)(6/"(,3&,7"%/U
MU(e"/(
B)*No*
LO'4)*&%(&/("12",-"9(-)(*"(&%()2"%(,3$):#-&%(#%9(&/(3&'348(#,-&."(&%($"9(
*4))9(,"44/
○
<>('"%"/(-$#%/,$&2-&)%#448(#,-&."(#$"(&%()2"%(,3$):#-&%=(53"%(8)6(-$"#-(
[@M(>$):(-3"($"9(*4))9(,"44/()>([@M/"(-3#-(9&'"/-/()%48()2"%(,3$):#-&%=(
8)6f9("12",-([@M/"(-)(9"'$#9"(-3"(LO'4)*&%
○
ZU(@)(5#8(-)(2$"9&,-
Q;(H)44)5&%'([@M/"(-$"#-:"%-()>($"9(*4))9(,"44(,3$):#-&%=(,)649(8)6(/-&44(9"-",-(-3"(
2$"/"%,"()>().#4*6:&%=(#('"%"(%)-("12$"//"9(&%($"9(*4))9(,"44/d(
A)*Yes*
@)-("12$"//"9(&%(-3"/"(,"44/=(*6-(&%()-3"$(,"44/(
○
E&4"%-(5&-3&%($"9(*4))9(,"44/
○
C)649(*"(&%(3&'348(,)%9"%/"9(,4)/"9(,3$):#-&%(6%#>>",-"9(*8([@M/"(
-$"#-:"%-
○
LU(@)(
ZU(@)(5#8(-)(2$"9&,-
3.#Transcription#is#controlled#by#the#interaction#of#regulatory#proteins#with#variable#
regulatory#elements.#
P-3"$(.#$&#*4"($"'64#-)$8(9):#&%/(>)$(-$#%/,$&2-&)%()>(W@M(R/-"2(]UB
?3"(4"//(#,,"//&*4"(-3"($"'64#-)$8("4":"%-/(#$"(-)(-3"(2$)-"&%/(-3#-(%""9(-)(
*&%9(-)(-3":=(-3"(4"//(4&7"48(&-(&/(-)("12$"//(#('&."%('"%"
B
M44("67#$8)-&,('"%"/(3#."(#(,)::)%(2$):)-"$(#%9(.#$&#*4"($"'64#-)$8("4":"%-/;
M44("67#$8)-&,(promoters #$"(*)6%9(*8(-3"(TATA-binding*protein*(TBP) #-(-3"(
?M?M(*)1;(
B
?3"(promoter ),,6$/(#-(-3"(*"'&%%&%'()>(-3"('"%"(#%9(&/(-3"(/&-"(53"$"(W@M(
2)48:"$#/"(*"'&%/(-$#%/,$&2-&)%;
B
^$):)-"$O2$)1&:#4("4":"%-/(#$"(4),#-"9(+6/-(62/-$"#:()>(-3"(2$):)-"$(#%9(-3"(
-$#%/,$&2-&)%(/-#$-(/&-"(#%9(3#."(/"\6"%,"/(6%&\6"(-)(/2",&>&,('"%"/
B
A67#$8)-&,('"%"/(3#."("%3#%,"$/=(2)/&-&."($"'64#-)$8(,)%-$)4("4":"%-/;
Enhancers ,#%(*"(4),#-"9(:)$"(-3#%(Sgg=ggg(*#/"/(#5#8(>$):(-3"(2$):)-"$=(&%(
&%-$)%/=()$(&%(6%-$#%/,$&*"9(`f()$(Tf(>4#%7&%'(/"\6"%,"/;(
[&>>"$"%-("%3#%,"$/(#$"(#//),&#-"9(5&-3(9&>>"$"%-('"%"/;(
○
Activator 2$)-"&%/(*&%9("%3#%,"$/(#%9(/-$)%'48(/-&:64#-"(-3"(
-$#%/,$&2-&)%(,):24"1
○
B
Silencers=(%"'#-&."(,)%-$)4("4":"%-/=($"2$"//($#-3"$(-3#%(#,-&.#-"('"%"(
"12$"//&)%;(
E&4"%,"$/(*&%9(2$)-"&%/(,#44"9($"2$"//)$/(#%9(-6$%()>>(-$#%/,$&2-&)%_-3"8(
3#."(-3"()22)/&-"(">>",-()>("%3#%,"$/;(
○
B
Eukaryotic+Gene+Regulation+I
C"9%"/9#8=( M2$&4(Sh=(]gSh SSY`h(MD
Document Summary
Gene expression changes allow eukaryotic cells to respond to environmental changes and cause distinct cell types to develop. In multicellular eukaryotes, differential gene expression is responsible for creating different cell types, arranging them into tissues, and coordinating their activity. To turn on a gene at a time and place. What it takes for a diploid precursor cell to develop into an organism. Sperm + egg = new diploid cell and individual in next generation for organism. With few exceptions, all cells in an organism have the same genes, but they express them differently. For example, both brain and liver cells transcribe housekeeping genes that code for enzymes and other molecules essential to the survival of all cells. However, liver cells transcribe some genes for liver-specific proteins, and brain cells transcribe some genes for brain-specific proteins. Brain cells for neurons to conduct its activities.
