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1
Q

non mammal cleavage

A
synchronous division
no growth
no transcription 
no g1 and g2 
dependent on mothers mRNA
2
Q

mammal cleavage

A
slower
not synchronous
plane of cleavage can differ between cells in same cycle
trnascription still occuring
undergo compaction (e cadherin)
3
Q

What is string protien in drosophila homologue of and how does it regulate CDK1

A

cdc25
cyclin b bind and activates CDK! and present G2 and mitosis
Wee1 phosphorylates tyr 15 on CDK1 - inact during Gā€
CDK1 phosphy again by AK
CDK1 activated when 1st phosphate on tyr removed
cdc25(string) removes phosphate on CDK1

4
Q

what does activated CDK1 do

A

activate histone 1 -chromosome condensation
activate MAP - spindle formation
inactivate lamin - nuclear envelope breakdown

5
Q

non mammals cell div after cleavage

A

non synchronous
occurs only in specific regions for tissues
G1 and G2
dependent on zygotic transcription

6
Q

potency definition

A

range of cell fates a cell line can become

7
Q

differentiation defn

A

process cell dopt final shape

8
Q

comminted deifnition

A

will become fate under normal env conditions but change in conditions will results in new cell fat

9
Q

determination

A

irreversible commitment of a cell to a particular fate

10
Q

p granules in C elegans an eg of

A

segregation of cytoplasmic determinants

11
Q

mutant phenotype of par1

mex5-6

A

no Pie1 localisation none in either d cell

in both cells (no degradation)

12
Q

mutant pie1

A

no gonads

13
Q

sperm entry at
par3/par6/aPKC distribution
Par1/Par2
Mex 5 where and role

A

posterior
anterior (tensile network contratct ant)
posterior (fill gap)
anterior degrade pie1

14
Q

volvox example of

A

asymmetric division and cell fate

15
Q

how is gonida cell in volvox formed

A

6th cell in anterior asymmetric - gonidal cell is big

16
Q

genes important in volvox gonida

A

gonidaless - imp in asym div plane
regenerator a - transcriptional repressor in somatic cell
late gonida - tran repressor in gonida - turn off somatic cell pr

17
Q

pharynx eg of

A

cell cell signalling giving fate

18
Q

WT fate of Aba

A

pharynx skinn neurones

19
Q

when p1 removed what happens

A

Aba on pharnygeal abp no muscle

20
Q

EMS removeed

A

Aba no pharyngeal

therefore EMS give signal for ABa pharyngeal cell

21
Q

P2 ablated

A

Abp make pharyngeal too (norm doesnt)

therefore p2 give signal make abp deaf to EMS signal

22
Q

change position EMS and P2

A

when P2 in contact with ABa doesnt make p cell

23
Q

what is APx1

A

signal on P2 membrane

24
Q

GLP1 is

A

receptor on ABa and ABp membrane

25
Q

evidence of lateral inhibiton in dros bristle

A

ablate cell which become bristle - neighbour take job

repeat see size of group

26
Q

what is the proneural cluster

A

cells which have been inhibited by sense organ precursor

27
Q

non autonomous is

A

cell doesnt need therefore signal

28
Q

autnomous

A

cell requires therefore receptor

29
Q

how is notch activated by delta

A

delta binds

notch intracellular domain cleaved

30
Q

notch mutant in bristle scneario

A

all develop as sense organ precursor as no lat inh rec

31
Q

delta mutant in bristle

A

bristle in middle as periphery cells get signal from other clusters

32
Q

what are the proneural genes that set up proneural cluster

A

achetate scute

33
Q

how do delta/notch causes lat inh

A

activate coactivator Su(H) which activates E(Spi) a repressor, inhibits of proneural genes achetate and scute.

34
Q

what genes form complex to activate trichome development

A

GL1, TTG1, GL3 - turn on GL2

35
Q

what in non functional complex of trichome development

A

Try, CPC form with TTG1 and GL3

36
Q

how does trichome spacing form

A

GL1 and GL3 canā€™t diffuse
TTG1 can and so can Try and Cpc
try and cpc diffuse to neighbours and repress trichome dev
limited how far can diffuse = where next trichome forms.

37
Q

what is a morphogen

A

a molecule that defines two or more cell fates at different concentrations

38
Q

Vulva dev in C. elegans eg of

A

relay system (cell pass signal on)

39
Q

role of anchor cell

A

give signal to become primary (P6p) or seconday (p5p/p7p) become vulva
ablate = no vulva

40
Q

is lin 3 rec or signal

A

signal - acts as a morphogen

41
Q

describe experiment show lin 3 is a morphogen

A

heat shock protein diff heats - diff amounts produced
no lin3- tertiary
little- secondary
lot -primary

42
Q

role of lin12

A

rec for lin 3, inv in its lateral inhibition on p5p/p7p - result in suppression of primary and induction of seconary cell fate

43
Q

describe epiboly

A

shhet merge cells thinner and cover larger area

44
Q

describe convergent extension

A

within sheet intercalate into thin line - imp in body axis

45
Q

where is VG1 in oocyte

A

vegetal cortex

46
Q

role of Vg1

A

drives animal/vegetal identity. (is a TGfbeta growth factor)

47
Q

spermy entry at

A

ventral

48
Q

what is cortical rotation

A

90 min after fertilisation 30degree turn of cortex
expose vegetal cortex to animal pole
forms Nieuwkoop centre

49
Q

role of Nieuwkoop centre

A

set up D/V polarity in blastula/defines dorsal side

50
Q

graft N.centre onto ventral

A

twinned embryo 2 dorsal sides

51
Q

effect of lithium

A

dorsalised embryo

directly inhibits GSK3 (no b catenin degradation)

52
Q

B catenin role

A
nuclear TF
after c rot on dorsal side
move to nucleus 
activates TF which specify dorsal side
when inject into ventral has dorsal effect
53
Q

role GSK3 and disheveled

A

B catenin degradation
only ventral as dishevelled block dorsally
cortical rotation moves disheveled to dorsal side

54
Q

role of spemann organizer

A

further pattern A/P, D/V and N syst induction

55
Q

role of Vegt

A

activates mesoderm induction

56
Q

organ of mesoderm

A

skeleton, muscle, kidney,blood.

57
Q

why is interactionof animal and vegetal pole important

A

mesoderm induction

58
Q

fate of dorsal mesonoto

A

notochord muscle

59
Q

fate of ventral meso

A

blood vessel

60
Q

1st stage of mesoderm induction

A

signal from vegetal
give ventral mesoderm default
(vegt likely)

61
Q

2nd stage mesoderm induction

A

Nieuwkoop centre indices spemann and notochord (b catenin)

62
Q

3rd stage mesoderm induction

A

spemann organiser gives signal modify dorsal side of mesoderm (BMP antagonist)

63
Q

4th stage of mesoderm induction

A

ventral pattering induction from ventral region (subdivide muscle,kidney, blood) (BMP)

64
Q

what features of Vg1 make candidate of mesoderm inducer

A

active can induce dorsal mesoderm in isolated animal cap and ventralised embryos
at low conc induces ventral mesoderm

65
Q

features of activin make mesoderm inducer candidate

A

has conc dependent action
high- notochord muscle
low - muscle

66
Q

VegT - why possible mesoderm inducer

A

when decreased no mesoderm

67
Q

describe role of noggin

A

is a dorsalising signal from organizer
BMP antagonist
chordin similar role

68
Q

BMP

A

bone morphogenetic protein
low at organizer high at ventral
give ventral signal/identity

69
Q

3 stages of gasstrulation

A

primary mesenchyme transition
invagination of endoderm
archeteron form

70
Q

3 stages of xenopus gastrulation

A

involution - rolling in of endoderm and mesoderm at blastospore
convergent extension of mesoder
epiboly - spreading of ectoderm as endoderm and mesoderm move in

71
Q

situs solitus is

A

normal

72
Q

situs inversus is

A

reversal of axis

73
Q

right isomerism

A

all body organ develop as if on right

74
Q

left isomerism

A

all body organ develop as if on left

75
Q

how was it found cili involve in L-R axis

A

inversus viscerum mut in mouse -random placement of internal organ (mut in pr which code for dynein)
situs inversus - reversal of handedness (mut in pr inversin part of cilia)

76
Q

when no flow at cilia node phenotype is

A

right isomerism

77
Q

disorganised flow at cilia node ptype is

A

left isomerism

78
Q

opposite direction of flow at cili node ptype is

A

situs inversus

79
Q

how is nodal affected bu cilia flow

A

nodal asym distributed by cilia
act Pitx2
lefty - anatgonist of nodal in LHS of embryo
no cilia no gene asym

80
Q

how is L/R axis established in echinoderm

A

nodal expr on RIGHT
larva rudiment on left - become adult organ
remove nodal - 2 rudiment

81
Q

snail L/R axis formed

A

sinistral - L rot
rostral - R rot
hve equivalent of nodal and pitx2
R twist nodal on R hs

82
Q

what is hensons node

A

in somitogenesis where cell proliferation occurs
constantly regress away from head
gives rise to tail

83
Q

what is presomitic mesoder

A

unpatterned tissue
12 somites worth of cells
is a constant length of 12cm

84
Q

how is somitogenesis different in chick to drosophila

A

somite bud off one by one

most anterior segment is the oldest

85
Q

what are the three features of control of somitogenesis

A

temporal - constant time
spatial - constant length
physical - how cells bud off

86
Q

how is hairy expressed in vertebrate somitogenesis

A

expressed in presomitic mesoderm and youngest somite
has inconsistent expression
as dynamic (shown fix two side of noto)
hairy expression matches 90 min rhythm, in a posterior to anterior wave
when a new somite about to form is conc in anterior

87
Q

what makes notch dynamic

A
notch activates hairy
hairy is a trans repressor
auto represses itself as unstable
hairy inh notch
this creates an oscillation of act hairy
88
Q

what makes somite form given distance from node

A

FGF8 gradient - made at node
when block fgf8 somite more posterior
FGF8 inh somite formation

89
Q

where does somite form

A

where FGF8 gradient and hariy act collide

causes gene expression changes allow somite to form

90
Q

what causes physical change in somitogenesis

A
N cadherin causes cells to stick
Eph/ephrin cells repel one another 
balance - control physical properties
in presomitic mesoderm layer of eph/ephrin expressing cells that do not break apart as N cadherin also expressed
somite form wheno n cad
91
Q

what is somitogenesis like in beetle

A

pair rule gene inv in circuit with less involvemnet form gap gene

92
Q

somitogenesis in chelicerate

A

pair rule gene expressed in stripes that progress from p to a in the unpatterned growth zome

93
Q

spider somitogenesis involves

A

hairy expression in pulsating fashion

94
Q

what are somites?

A

segments of paraxial mesoderm

95
Q

what are the 2 clusters of homeotic gene in drosophila

A

bithroax

antennapedia

96
Q

how many clusters of hox gene in mammals and why?

A

four clusters with paralogs

why KO less extreme in

97
Q

what do high levels of retinoic acid do when injected in utero

A

cause misexpression of hox genes

more posterior structures

98
Q

where is retinoic acid concentration highest and why?

A

caudal end of hindbrain

as this where enzyme which makes is - retinaldehyde dehydrogenaseIII

99
Q

what does an acitvated retioic acid recpetor have on it

A

has coactivator bound protein which bindss to receptor binding element to activate genes

100
Q

differences between vertebrate and drosophila hox genes (4)

A

vert x100 more compact
shared regulatory elements in vert independent in dros
hox domains est gap/pair rule in dros vs ra and somitogenic clock in vert
vert have FGF8 grad

101
Q

genetic causes of developmental defects

A

single gene disorder (FGFR3 and achondroplasia)
multigene disorder
age
inbreeding

102
Q

eg of broad class developmental malformation

A

failure to seperate

failure to fuse

103
Q

epigentic dev defect

A

beckwithh wiedemann syndrome - over grown tumours on kidney risk, slows by 8 yrs
due to epigen alterations on chr 11p15

104
Q

what are teratogens

A

env agents which alter development but not by mutation

105
Q

eg of teratogens

A

cyclopamine - produced by false helleborne easten by pregnant animal = cyclopic young
works by blocking Shh signal as binds and inhibit smo
Thalidomide bind cereblon, which forms complex imp in limb outgrowth and expression of FGF8 no thalidomide no fgf8

106
Q

how does sonic hedgehog signalling work

A

Shh binds to patched and inhibits
patched inhibits smoothened
smooothened act Gli ~(TF) switch on genes
imp in pattering midline structures notochord and fllor plate of neural tube

107
Q

what is basal cell carcinoma

A

most common cancer skin
aar of hyperact of shh pathway
cyclopamine pot treatment

108
Q

why is cyclopamin pot treatment of meullblastoma

A

brain tumour

clocks shh

109
Q

where are embryonic stem cells found

A

icm of blastocyst

110
Q

where are adult stem cells found

A

hair follicle
crypts
bone marrow

111
Q

what is transdifferentiation

A

stem cell from one organ given correct signal to contribute to another organ.

112
Q

what is the cocktail of TF that make ips

A

OCT2/4,SOX2, KLF4 CMYC.

113
Q

how long after fertilisation does segmentation occur in drosophila

A

8 hrs

114
Q

how many parasegments in dros

A

14

115
Q

bicoid lof ptype is

A

2 post ends

116
Q

where is bicoid mrna localised

A

anterior

117
Q

where is bicoid pr

A

in gradient as embryo a syncitium, highest at ant

118
Q

ectopic expression of bicoid ptype

A

head

119
Q

how does bicoid regulate target gene

A

bind promotor

120
Q

hunchback mut have

A

head/thorax defect

121
Q

role of nanos/ expression

A

in pos

repress hunchback

122
Q

interaction between bicoid and caudal is

A

bicoid inh caudal translation

therfore in post

123
Q

mut ptype of gap genes

A

consecutive segments

124
Q

what are gap gene expression control by

A

maternal effect genes

gap gene cross reg themselves

125
Q

what are pair rule gene control by

A

primary -gap gene and bicoid puts into 14 stripes of gene

secondary - reg by primary

126
Q

role of pair rule gene even skipped

A

expr in odd paraseg
mut have no para seg
trnscriptional repressor

127
Q

role of fushi tarazu

A

is a secondary pair rule gene
expr in even no paraseg
encode transcriptional act (complemenery function)

128
Q

what is the antennapedia mut

A

GOF antenna into leg like appendages

129
Q

what is probiscipedia mut

A

gof

proboscis into leg like structure

130
Q

what are features of a hox gene

A

homeodomain

hexapeptide binding motif (diagnos hox id)

131
Q

role of polycomb protein

A

remodel chromatin
lock in stable expression
gene off/silenced

132
Q

role of trithorax protein

A

main action to maintain gene expression
keep chromatin open
bind dna and alter structure of chromatin

133
Q

no polycomb and trithoraz protein mean

A

hox gene expression set up but not maintained

134
Q

LOF mut in dros hox

A

next hox gene will fill/take on identity

135
Q

GOF mut in dros hox

A

transform anterior to more posterior identity

when express two hox gene most posterior wins

136
Q

desicrbe the bithorax complex in drosophila

A

3 genes
ubx - when del =wing in 3rd seg as T3 get T1/T2 identity
with antp expr as ubx norm repress antp

137
Q

what is macroevolution

A

certain change cause big morpho change

138
Q

what does ubx supress

A

leg formation

139
Q

how does abdb reg yellow body

A

cis reg element

140
Q

does brine shrimp ubx repress limb

A

no ehy thoracic limb

141
Q

how is plant development differ from animal

A

post embryonic development
continuous growth as meristem
can change development programme according to environmental cues
cells can not move

142
Q

anticlinal division

A

perpendicular to surface

143
Q

periclinal division

A

parallel to surface

144
Q

what role of gene angusfolia

A

control width of leaves

145
Q

rotudilfolia 3 role

A

control length of leaves

146
Q

what are the four parts of plant embryo

A

cotyledon
meristem
hypocotyl
root

147
Q

what is the apical cell division programme

A

x2 anticlinal

1 periclinal

148
Q

basal cell division programme

A

expand longitudinal

divide periclinal

149
Q

wox gene role

A

determine cell div programme

150
Q

where are wox2/wox8/wox9 expressed

A
wox2 apical 
           by 16 cell only top
wox8 suspensor 
wox9 suspensor
          16 cell in bot embryo
151
Q

wox2 mut affect

A

change 8-16 cell division from periclinal to anticlinal

no embryo made

152
Q

wox8 9 mut

A

abnormal cell div in embryo and suspensor

153
Q

ATMERISTEM LAYER1 expression/mutant ptype

A

in apical
after 16 only in l1 layer of epidermis thruout plant life
mutant lethal w no epidermis

154
Q

what gene does CUC3 turn on

A

shootmeristemless (STM1) in late globular

155
Q

role of STM1

A

shoot apical meristem identity

156
Q

Plethora (PLT) gene role

A

root identity

157
Q

plt is dose ddependent what does it specify at low/high

A

low - promote mitotic activation of stem cell daughter

high - promote stem cell identity and maintenance

158
Q

at 1 cell stage where is auxin flow

A

suspensor to embryo

159
Q

what PIN maintain auxin flow upto 8 cell stage

A

pin7/pin1

160
Q

auxin flow from globular atage onwards is directed

A

into tip of cotyledon and root by pin1

161
Q

where is auxin flow directed in heart stage

A

internally by pin 1

162
Q

what is the mutant ptype of LEC1

A

hair on cotyledon

overexpress -embryo everywhere

163
Q

rolfe of wuschel

A

only in SAM make initial cells

164
Q

role of clavata

A

clavata in pathway which anatgonise wus to maintain cell proliferation

165
Q

what genes are in the central zone

A

STM Wus

166
Q

what genes are in peripheral zone

A

clavata

167
Q

what are decussate leaves

A

at 90 degree

168
Q

what are distichous leaves

A

180 degree

169
Q

what are the hypothesis for leaf development

A

inhibitory field
biophysical
general control of genes

170
Q

what is inh field hypo

A

position of pressent primordia important for next primorida
pre existing primordia inhibit new priordia
when isolate one the next one forms noramlly but one after forms closer w=to where removeed primordia shoud be
strongest at youngest

171
Q

what is the biophysical hypothesis

A

uneven thickness

weaker area physical force = new leaf form

172
Q

role of expansins

A

make cell wall weaker where they are present
loosen linkage between cellulos microfibrils
ectopic expr = new primordia

173
Q

role of cytokinin

A

regulate size of stem cell niche

174
Q

role of AHp6,

A

inhibits cytokinin and establishes pattern of signalling in meristem

175
Q

what genes aare turned off when acquiring determinate leaf identity

A

KNOX1 and STM1 are merostem specific genes

176
Q

what genes are turned on for determinate leaf identity

A

ARP genes promote determinate growth and differentiation

177
Q

what are adaxial genes

A

HDZIP phb,rev,phv

178
Q

what role does miR65 have in making phb only expressed in adaxial

A

cleaves transcript, therefore confing to one side as only expressed abaxial

179
Q

abaxial genes

A

yabby

kandi

180
Q

what does blade devlopemtn require

A

ab/ad boundary

181
Q

role of CUC

A

seperates cotyledon

182
Q

role of CUC2

A

growth repressor

when continously expressed no serration

183
Q

interaction of auxin and cuc2

A

auxin repress cuc2

184
Q

role of speechless in guard cell development

A

asym entry div

185
Q

role of mute in guard cell development

A

control cell fate (smallest become guard cell)

186
Q

FAMA role in guard celll development

A

symm exit division

187
Q

role of EPF2 in guard cell development

A

role in spacing
ligand produced in stomata diffuses inhibits neighbours from becoming guard cell
over expr = no guard cell

188
Q

what activates Flowering locus T (FT)

A

constants

189
Q

what is constants controllled by

A

circadian rhythm
degraded at dark therefore peak at end of day
constants bind FT promoter and act transcription

190
Q

what is FD

A

TF FT bind to

together activate AP1 which is sufficient for floral induction

191
Q

what is leafy

A

master gene for floral id is a TF

192
Q

what antagonises leafy expression

A

TFL1

193
Q

example of a b c genes

A

a - apetala 1,2
b- apetala 3 pistilata
c - agamous

194
Q

agamous mu

A

indeterminate meristem

195
Q

cycloidea mut

A

no dorsal petal all ventral

196
Q

radialus mut

A

all ventral petal

197
Q

divaricata mut

A

show lateral default