Exam III - Zaidi Flashcards
Homologous proteins are functionally
interchangeable
Blastula consists of a …… facing the external medium
sheet of epithelial cells
What gives rise to the endoderm?
sheet of epithelial cells
Endoderm is the precursor of
gut, lung, and liver
Ectoderm is the precursor of the
nervous system of and epidermis
Mesoderm is the precursor of
muscles and connective tissue
Higher organisms have several homologs of the same gene, this is an example of…
gene duplication
Cells that are fated to develop into a specialized cell type despite changed in environment are called
determined
cells that can change rapidly due to environmental alterations are called
completely undetermined
cells that have some attributes of a particular cell type but can change with environment are called
committed
Induction of a different developmental program in select cells in a homogeneous group leading to altered character
inductive signalling
A long range inductive signal that imposes a pattern on a field of cells
morphogen (inhibitor and inducer gradients)
Three factors of diversity in pattern:
gene duplication, presence of other signals, previous experiences of the cell
signaling pathways consist of a handful of ….
conserved family of proteins
response to signaling pathways depends on
spatial and temporal expression of different sets of genes
what is the ligand and receptor family of
RTK
EGF, FGF, Ephrins
EGF, FGF, and Eph receptors
what is the ligand and receptor family of TGFB
TGFB, BMP, Nodal
TGFB receptors, BMP receptors
what is the ligand and receptor family of Wnt
Wnt
Frizzled
what is the ligand and receptor family of Hedgehog
hedgehog
patched, smoothened
what is the ligand and receptor family of Notch
delta
notch
phase one of neural develop.
(genesis of neurons) diff. cell types develop independently at separate locations in embryo according to local program and are unconnected
phase two of neural develop.
(axon/dendrite growth and synapses)axons and dendrites grow out along specific routes setting up a provisional but orderly network of connections
phase three of neural develop.
(refining synaptic connections)into adult life, connections are adjusted and redefined through interactions with distant regions via electrical signals
CNS (brain, spinal cord, retina) is derived from
neural tube
PNS (nerves, sensory neurons) is derived from
neural crest
A nerve cell developing from epithelial cell contains a membrane-bound inhibitory signal protein called delta. What is the receptor protein?
receptor protein notch on an inhibited epithelial cell
Pattern formation, differentiation, secretion of ECM
TGFB
Depends on proteoglycans for fxn, active latent genes, transcription repression to activation
sonic hedgehog
Dorsal is to roof plate as ventral is to
floor plate
monomeric GTPases that control assemble and disassembly of actin filaments
rho, rac
Two important classes of homophilic cell adhesion molecules
immunoglobulin fam.
cadherin
Favors axonal outgrowth
laminin
inhibit axonal outgrowth
chondroitin sulfate proteoglycans
Commissural neuron guidance
first stage depends on secretion of netrin by floor plate
binding of netrin to TRPC allows entry of Ca.
causes growth cone movement
Commissural neuron guidance
midline secretes slit
receptor is roundabout. repels growth cones.
growth cones sensitive to semaphorin to trap it between two repellents
target cell of neurons produce limited amount of
neurotrophic factors needed for survival
cells w/o enough die
What enters the glutamate NMDA receptor that triggers change in synaptic strength ?
calcium
physical structure changes.
neurons that fire together wire together
Zygote
totipotent
ES cells
Pluripotent
adult stem cells
multipotent
founder stem cells divide and gives to
daughter cell that remains a stem cell and set of transit amplifying cells
Only actively dividing cells of epidermis
basal cells 4 and basal cell lamina 5
Numerous desmosomes that attach to keratin filaments
prickle cells 3
Epidermis is stratified and made up of
keritinocytes
Waterproof barrier and boundary between active and outer dead epidermis
granular cells 2
Squame
outermost, dead 1
Epidermal stem cell proliferative potential correlates with expression of
B1 subunit of integrin (lots at bulge of hair follicle)
controls contact to basal lamina
factors that govern renewal of epidermis
rate of division
if one daughter cell remains a stem cell
rate of division of transit amp. cells
timing of exit from basal cell layer
Loss of sebaceous glands (due to cells continuing to divide after losing contact to basal lamina)
overactive hedgehog
Failure of hair follicle development
loss of Wnt signaling
Extra hair follicle development, leading to tumors
up-regulation of wnt
restricts the size of stem cell population
notch
Plays a role in repair of skin wounds
TGFB
Specialized epithelium- sensory tissue of nose, ears and eyes is derived from
ectoderm
Apical end of sensory cells detects
external stim, converts it to a change in mem. potential
basal end of sensory cells
make synapse with neurons
Relay stations called glomeruli are located in
olfactory bulbs on each side of the brain
Stem cells in lining of brain ventricles divide and produce new stem cells and then migrate to
olfactory bulbs, where they will differentiate
embryoid body + RA + (insulin +thyroid hormone ) =
adipocyte
embryoid body + RA
neuron
Macrophage = embryoid body + …..
(macrophage colony stim. factor) + interleukin-3, 1
Smooth muscle cell = embryoid body + ….
dibutyryl cAMP + Retinoic acid
embryoid body + fibroblast GF + ( fibroblast GF2, epidermal GF ) + (fibroblast GF2, platelet-derived GF) =….
astrocyte and oligodendrocytes
Key determinants of ES cell character are four gene regulatory proteins:
Oct4, Sox2, Klf4, and Myc
Fibroblasts can be reprogrammed with the help of transcription factors to create
pluripotent stem cells
