Molecules and Mechanisms E1 Flashcards
(108 cards)
1
Q
Resact
A
from sea urchin egg jelly coat, binds to a receptor on sperm to lead it to egg.
2
Q
RGC
A
Receptor guanyl cyclase, what resact binds to. forms intracellular cGMP in sperm
3
Q
cGMP
A
in sea urchin sperm, opens calcium channels in cell membrane to let Calcium enter sperm
4
Q
fucose sulfate
A
a sulfated card that binds to receptor on sperm to initiate acrosomal reaction. The receptor it binds to acivates sperm membrane proteins
5
Q
Three mechanisms activated in sperm during acrosomal reaction
A
- Calcium transport channel that lets calcium enter sperm head
- Na/H pump that lets Na in and H out
- IP3 phospholipase enzyme releases calcium from inside sperm
6
Q
Two effects of calcium increase in acrosomal reaction of sea urchin
A
- fusion of acrosomal membrane with adjacent sperm cell membrane to release digestive enzymes
- activates protein RhoB to make acrosomal process
7
Q
RhoB
A
GTP-bdinging protein in sperm that polymerizes actin to make the acrosomal process. Activated by IP3
8
Q
Bindin
A
acrosomal membrane protein of sperm that recognizes and binds to surface of egg
9
Q
ERB1
A
Bindin receptor organized in complexes on vitelline envelop of egg
10
Q
Calcium source for cortical granule reacton
A
calcium comes from the ER of the egg cell and is self-propagating
11
Q
IP3
A
- In sperm, releases calcium to fuse acrosomal membrane with sperm cell membrane (and release digestive enzymes); activate protein RhoB to make acrosomal process
- In egg, releases Calcium from ER. Made from PIP2 being split by enzyme PLC
12
Q
PIP2
A
Found in egg cell, split by PLC to make DAG and IP3
13
Q
PLC
A
splits PIP2 to make DAG and IP3 for the cortical granule reaction. y-PLC is activated by an Src family of protein kinases in cortical cytoplasm
14
Q
Src protein kinases
A
found in cortical cytoplasm of egg, activate y-PLC to generate IP3 and DAG by splitting PIP2. Activated by G proteins
15
Q
G proteins
A
found in cortex of egg, serve to activate Src kinases, which activate PLC for inducing cortical granule reaction
16
Q
2 effects of sperm binding/fusion to egg cell membrane
A
- Sodium influx
- Kinase stimulation
17
Q
Role of Sodium in fertilization of sea urchins
A
causes a change in egg membrane potential and leads to fast block to polyspermy
18
Q
Role of kinase stimulation from sperm binding to egg membrane
A
activates PLC, which does lots of things
19
Q
2 Roles of PLC in fertilization
A
- IP3 production to release Calcium
- Diacylglycerol production to increase intracellular pH
20
Q
Role of diacylglycerol in sea urchin fertilization
A
activates protein kinase C, which leads to Na/H pump exchange and increase in pH
21
Q
Protein Kinase C
A
found in egg, activated by diacylglycerol, leads to exchange of Na/H. Increase in Na ionsin cell causes rise in pH
22
Q
Role of increase in pH in fertilization
A
together with Calcium increase, stimulates new DNA and protein synthesis
23
Q
influx of K+ in mammalian sperm
A
leads to hyperpolarization of sperm membrane potential
24
Q
soluble adenyl cyclase
A
in mammalian sperm, activated by increase in Calcium and bicarbonate in sperm. Makes cAMP from AMP
25
cAMP
activates protein kinase A
26
PKA
activated by rise in cAMP in mammalian sperm, leads to activation of protein tyrosine kinases and inihibition of PTP - phosphotryrosine phosphatase
27
PTK
leads to capacitation of mammalian sperm
28
SED1
protein in sperm that has a slight bond to zona pellucida
29
ZP3
glycoprotein in zona pellucida of mammalian egg that binds to sperm and leads to acrosomal reaction by causing calcium-mediated exocytosis of acrosomal vesicle
30
Cyclin B
contributes to biphasic cell cycle of cells. Makes up MPF. Synthesis of it allows progression to Mitosis, while degradation allows cells to pass to synthesis phase
31
MPF
mitosis-promoting factor. Highest during mitosis, but can't find it during synthesis. Shift in phases of cell cycle is driven by gain and loss of this molecule's activity.
Made of cyclin B and cyclin-dependent kinase
leads to rapid, synchronous cell divisions
32
Order of sea urchin first 3 cleavages
meridional, meridional, equatorial
33
Otx and B-catenin
activate Pmar1 gene in cleavage. These are maternal cytoplsm-derived Transcription regualtors that are inherited by micromeres
34
Pmar1 genee
repressed HesC, which is also a repressor. Activated by Otx and B-catenin, which are concentrated in vegetal pole of egg cell.
35
molecules involved in double-negaive gated micruit for micromere specification
Otx, B-catenin, Pmar1, HesC, genes Alx1, Thr, Etx, Delta
36
HesC
repressor of genes involved in mircomere specification: Alx1, Thr, Ets, Delta
prevents formation of skeletoal mesenchyme cells in micromeres
37
double-negative gated circuit in veg2 cell
In veg2, this circuit is broken because Pmar1 not activated, so HesC represses skeletogenic genes
38
Skeletogenic mesenchyme cells
* cells specified to autonomously ingress into blastocoal and become skeleton of sea urchin
* also induce neighbors to become endoderm and non-skeletogenic mesenchyme cells (pigment; coelom cells)
39
Dishevled and B-catenin
found in cytoplasm, inherited by micromeres at fourth celavage. these are the initial regulatory inputs for micromeres
40
Disheveled
prevents degradation of B-Catenin in micromeres and macromeres. it is located in the vegetal cortex
41
B-catenin role in cleavage
* specifies micromeres. accumulates in cells fated to be endoderm and mesoderm and causes them to develop autonomously.
* Specifies the vegetal half of the egg
42
Blimp1 and Wnt 8
form a positive feedback loop to make more B-catenin. Blimp1 is also activated by Otx adn maternal B-catenin
43
ES (early signal)
* inducing signal of micromeres that is controlled by Pmar1 and HesC
* instructs other cells to be endo/mesoderm and can also establsh second axis when micromeres are transplanted to animal region of the embryo
44
Notch
a protein that tells cells below it to become nonskeletal mesenchyme cells. activates by Delta juxtacrine protein
45
Differentiation of cells in micromeres
become skeletogenic because of early signal and delta proteins in double-negative gated channel of Pmar1 and HesC
46
commitment
cell fate resulting in differentiation
47
specification
differentiation when cells are in neutral environment. this type of commitment is reversible, so it is not a true commitment
48
determination
type of cell developmental commitment that results in autonomous differentiation. This means the cells will differentiate even in a nonneutral environment. Irreversible
49
Two types of cell developmental commitment
specification and determination
50
two types of cell specification
autonomous and conditional specification
51
autonomous specification
cytoplasm no homogeneous, but instead contains different inheritants and derterminants
However, cells know their fate and become determined without interaction from other cells
micromere cells are this
52
conditional specification
cells achieve respective fates by interacting with other cells
they are specified by paracrine factors secreted by neighbors
53
cleavage of sea urchin animal half/pole
* 4th cleavage is meridional
* 5th cleavage is equatorial and forms animal 1 and 2 layers
* 6th cleavage is meridional
* all of these cleavages are equal, meaning cells are same volume
54
cleavage of sea urchin vegetal half/pole
4rth cleavage is equatorial and uneven, forming 4 macromeres and 4 micromeres
5th cleavage, macromeres divide meridionally to form 8 cells; micromeres divide equatorially
6th cleavage is equatorial and even for all
55
fate of animal half of sea urchin egg
becomes epithalium and neurons. so skin and neurons
56
1st vegetal half fate in sea urchins
becomes ectoderm (top half) and endoderm (bottom half)
57
2nd vegetal half fate in sea urchins
becomes coelom, non-skeletogenic mesenchyme - muscles, pigment - and endoderm
58
so what do large micromeres become?
skeletal mesenchyme
59
What is the first gastrulation event?
ingression
60
gurken
* gene in drosophila, made in nurse cells, gets transpirted to oocyte nucleus and translated to protein.
* serves to anchor nanos mRNA to posterior end of embryo
61
Par1
in drosophila, organizes microtubules with (-) cap and (+) growing ends to anterior and posterior ends of oocyte
62
Kinesin
motor protein ATPase that sends molecules to (+) posteror end of drosophila embryo. moves Oskar mRNA and nanos
63
Oksar
an mRNA in drosophila transported by kinesin to (+) posterior end of the embryo
64
Dynein
in drosophila, a motor protein that transports mRNA to anterior (-) end of embryo
transpors bicoid
65
Bicoid
* mRNA in drosophila that goes to anterior (-) end of embryo
* causes formation of acron (most anterior end), head, and thorax. Without it the mutant has two tails (Telson)
66
Torpedo
* Gurken receptor on posterior end of drosophila embryo
* Inhibits expression of Pipe gene
* causes follicle cells to differentiate to dorsal morphology
67
Pipe
gene in drosophila that activated Nudel and is only found in ventral follicle cells.
68
Nudel
activated by Pipe in drosophila. activates 3 serine proteases: gastrulation defective (gd), snake, and easter genes
69
What happens after Nudel is activated in drosophila?
* Nudel and factor x split gd protein
* Gd splits snake protein
* Snake protein cleaves Easter protein
* Easter splits Spatzle
* Spatzle binds to Toll receptor protein
70
Toll
* receptor protein activated by binding of Spatzle
* activates Tube and Pelle
71
Tube and Pelle
activated by Toll
phosphorylate Cactus protein. Cactus is degraded and released from Dorsal protein
72
Dorsal
protein separated from Cactus when Cactus is degraded after being phosphorylated by Tube and Pelle
Dorsal protein enters nucleus and ventralizes the cell
73
molecules involved in ventralizing follicle cells in drosophila
Pipe, Nudel, Gd, Snake, Easter, Spatzle, Toll, Tube, Pelle, Cactus, Dorsal
74
Cactus
protein that is phosphorylated by Tuve and Pelle, causing release of dorsal protein into cell neuclus to ventralize it
75
2 major types of cells in an embryo
epithelial cells and mesenchymal cells
76
epithelial cells
tightly connected to one another in sheets or tubes
77
mesenchymal cells
unconnected to one another and operate as independent units
78
Ectoderm
becomes nervous system, skin, eyes, inner ear
79
mesoderm
becomes muscles, skeleton, and circulatory system, which includes kidneys, and gonads
80
Endoderm
digestive system and respiratory tract
81
invagination
infolding of cell sheet to form a cavity
82
ingression
migration of individual cells to center of embryo
83
3 crucial axes of embryo
* anterior/posterior
* dorsal/ventral
* right/left
84
blastocoel
hollow sphere of cells with central cavity.
85
tight junctions
connect the blastomeres into an epithelial sheet
86
blastula
* 1 cell-layer thick, adhered to hyalin layer
* all cells eventually become the same size, because micromeres slow their division while others catch up
87
cells furthest from blastocoel
become ciliated
88
meridional cleavage
vertical cleavage of cells
89
equatorial cleavage
horizontal cleavage of cells
90
Cleavage characteristics of sea urchin
isolecithal, radial holoblastic, fast and synchronous (because little yolk), size of blastomeres identical through 3rd cleavage, then different
91
why/how does biphasic cell cycle occur
because cyclin doesn't have to be transcribed. instead, cell cycle is using stored machinery. Division slows when run out of mRNA for cyclin and need to transcribe more cyclin gene
92
mid-blastula transition
when synchrony of biphasic cell cycle is gone and the embryo has to undergo further development
93
3 objectives of gastrulation
1. Generates 3 germ layers
2. bilateral symmetry
3. establishes new and unique cel interactions which influence future developmental events
94
95
basal lamina
what fibronectin, lamain, collagen, and ellastin cells must bind to
96
cadherins role
family of cell-to-cel adhesion molecules that hold cells of blastula togehter as a sheet
97
what 3 factors allow cells to move in embryo
concentration of matrix, orientation of matrix, and contact guidance
98
gastrulation: which movement happens first?
ingression first, then invagination
99
how does invagination happen?
inner halin membrane swells from absorbing water and pulls vegetal plate inwards as outer part constricts
100
aboral
side of embryo away from the mouth
101
when does pattern formation start in drosophila
super early, while egg still undergoing ovulation. so before second meiotic division
102
what is pattern formation
specialization and organization of phenotypes in flies, looking at multiple axes
103
mRNA for which drosophila patterning proteins are evenly distributed?
for caudal and hunchback
104
Caudal
protein in drosophila around posterior end
105
Hunchback
drosophila protein found in anterior end
106
bicoid vs. caudal
bicoid protein blocks caudal mRNA from becoming caudal protein
107
nanos and hunchback
nanos protein blocks hunchback mRNA from forming hunchback protein
108
