Development II Flashcards
True or False: All vertebrates undergo the same basic process in early development.
True
Which eggs has a body axis set up (polarized) prior to egg fertilization by the vertebrate equivalent of the fly’s maternal effect genes?
Xenopus
What is the pole that produces the ectoderm (precursor of the skin and the N.S)?
Animal Pole
What is the pole that produces the endoderm (precursor of the gut)?
Vegetal pole
Cells in between the animal and vegetal poles generate the _______________ –> a precursor of muscles and bones.
Mesoderm
The ____________ of egg creates the second body axis with ventral structures forming at the side of the egg where the sperm entered.
fertilization
During ________, the embryonic cells start to reorganize (cells begins to move)
Gastrulation
Where do the cells from the animal pole move down to?
A structure called a dorsal lip or organizer
At the dorsal lip –> cells leave the ectoderm and migrate into the interior of the embryo to form the _________ –> precursor to muscles.
mesoderm
The ______________- have the ability to change the fates of the cells around them by inducing (environmentally determined) some ectodermal to become mesoderm.
dorsal lip organizer cells
If you transplant ectoderm cells from a portion of donor embryo that is destined to the animal’s head region and put them into a host embryo’s tail region _______________.
these donor cells will become the normal tail structures
Who performed a classical experiment, transplanted dorsal lip induces a new embryo, and was awarded a Nobel Prize in 1935?
Hans Spemann
After the axis is formed what occurs next?
Neural Induction
What is the primary process of that development of the nervous system in vertebrates?
Inductive (environmentally influenced) process
After the induction of the mesoderm by the organizer, the structures in the mesoderm partially the ___________–> induce the formation of the neural plate in the ectoderm.
Notochord
True or False: The neural plate then protrudes upward forming the neuronal folds and the neural crest.
True
What would the neural form when they eventually fuse?
Form the neural tube
The precursor to the brain and the spinal cord
The ________________ are the percuroser to the peripheral nervous system and several other cell types.
neural crest cells
The regional specific neuronal identity is determined by a process called
Pattern formation
The general scheme for regional specification throughout the vertebrate nervous system is that the responses of Pluripotent precursors are first recruited according to its __________________.
anteroposterior position
Cell phenotype is then further restricted according to _________________.
Dorsoventral position
The anteroposterior and dorsoventral specification is determined by ___________________.
gradient of regulatory genes
What is one remarkable finding in developmental biology?
Homologous genes specifying segmentation in the embryos of Drosophila are conserved in vertebrates and often serve a similar function.
True or False: The vertebrate embryonic hindbrain has a segmented structure.
True
What kind of genes regulate the segmentation in the fly to determine the fate of cells vertebrate rhombomeres in a segmental specific way?
Homologous genes (Hox Genes)
Notochord not only induces the formation of the neural plate but also influence ___________________ after the neural tube forms.
cell fates in the developing nervous system
What molecular signals from the notochord cause the differentiation of a special group of cells in the ventral spinal cord called floor plate cells?
Sonic hedgehog gene
The floor plate cells then releases signals causing ______________ near the floor plate to differentiate into ____________.
neuronal precursors near the floor plate to differentiate into motor neurons.
If we draft a donor notochord (N) into a host embryo ____________________.
a new floor (F) plate and motor neurons will form
The peripheral nervous system neurons are derivates of _________________.
Neural crest cells
True or False: The multipotent precursor cells from the neural crest differentiate into several different cell types depending on which pathways they migrate along in the developing embryo.
True
For the PNS, Cells which migrate ventrally become sensory neurons in the _______________, cells which migrate _______ the nearly tube become neurons in the ______________.
dorsal root ganglion
beyond
sympathetic ganglia
Sympathetic ganglia cells which migrate below the notochord become chromaffin cells in the _________________ and other neurons and cell migrate directly beneath the ectoderm becomes ___________ in skin.
adrenal medulla
melanocytes
True or False: These different cell fates for the different progeny of neural crest cells are not genetically pre-determined.
True
The cell’s fates are altered by the environment they migrate through __________________.
Inductive mechanisms
Some of the specific cues that migrate neural crest cells respond to the environment are _______________.
Growth factors
What is the dissociated cell culture experiment used for?
It can be used to determine these factors.
For central nervous system, the future central nervous system develops from __________________.
wall of the neural tube
True or False: The nuclei of the cells in the primitive neural tube move back and forth during cell cycle.
True
When cells become post __________ they migrate way from the __________ zone and from the maztle zone. Their process make up the __________ zone.
Mitotic
ventricular
marginal
Neurons in the future brain later migrate into the ___________zone to form a _____________ plate.
marginal
cortical
The migration of the neurons is dependent on ______________.
Redial glial cells
What do redial glial cells create?
Create the road where new neurons can move along.
L
Later born neurons migrate pass earlier born neurons creating an ________ growth pattern
inside out
What was injected during the embryonic development to show the inside out pattern?
Hythumide
After neurons have differentiated, they start sending out ______ and _______ to make connections.
axons
dendrites
The tip of the growing axon or dendrite is called _____________ .
_______________ extend and retract lamellipodia and flilopdia, as if sampling substrate everywhere.
Growth Cone
True or False: Filopadia adheres to an appropriate substrate and pull the growth cone in their direction.
True
The dynamic of growth cone are mediated by two process
(i) ____________________
and
(ii) ____________________________
polymerization and depolymerization of actin filaments
mysoin-mediated movement of actin filaments on microtubules
Growth cone assembles macromolecular adhesion complexes to _______ extracellular protein to actin filaments.
Link
The adhesion receptors linked to _____________ through _______________.
actin filaments through adhesion complexes
These adhesion receptors traveling within ____________ along ______________ may regulate axon outgrowth.
recycling endosome
microtubules
In addition, _____________ can direct the extension of growth cone.
Axon guidance receptors
If the filopodium contacts an attractive substrate in the environment, actin filaments are _______________ by attachment to the substrate. Actin polymerization cause protrusive growth of growth cone.
immobilized
On the other hand, if a ______________ contracts a repulsive substrate there is a rapid and complete collapse of the ____________ caused by actin depolymerization.
filopodium
What cues in the environment do the filopodia react to?
The molecules in the environment that determine how favorable the substrate are cell adhesion molecules and extracellular matrix adhesion molecules. These molecules are environment permissive cues.
Cell adhesion molecules is expressed on the ____________-of the flipodium.
Also, they are ____________ or ___________________
Membrane
Transmembrane or membrane-associated glycoproteins
What are the three families of the cell adhesion molecules?
The Immunglobulin (IG) Superfamily
Cadherins
Integrins
Immunglion Superfamily are either _________ (bind to themselves) or ______________ (do not bind to themselves but rather to other types of molecules)
Homophilic
Heterophilic
Cadherin are also _____________ but unlike IG Superfamily, Catherine are also _________________ in their binding.
Homophilic
Calcium dependent
Integrins are ____________ bind to the extraceullar matrix fashion molecules like _________ and __________.
They are ________
Dimeric receptors
lamin
fibronectin
Heterophilic.
