Term
|
Definition
-each cell becomes ciliated, begins to rotate.
-protein junctions are formed between cells |
|
|
Term
| late blastula(tenth devision) |
|
Definition
cells at vegetal pole begin to thicken to form *vegatal plate*
-fate of cells have become specified |
|
|
Term
|
Definition
when a cell starts expressing a unique subset of their genes
-expression of genes depends on the type of organism, enviormental conditions,stage of development |
|
|
Term
| Differential Loss of Genetic Material |
|
Definition
– Each cell only inherits specific genes required to differentiate in a
particular cell |
|
|
Term
| Selective Gene Amplification |
|
Definition
Segments of nuclear DNA are replicated
-Frog oocytes have extra genes for ribosomal RNA |
|
|
Term
| Genomic Equivalence with Differential Gene Expression |
|
Definition
-All cells in an organism have complete and equivalent sets of genetic
information
-All cells in an organism have complete and equivalent sets of genetic
information
-Different regions of chromosome are “puffed up” in different
times and in different cell types |
|
|
Term
| Post-Transcriptional Modification of mRNA |
|
Definition
“Capping” of 5’ end and “Tailing” of 3’ end
• Controls over mRNA stability
• Depends on base sequence, length of poly-A tail,
and which proteins are attached to it
Splicing of exons |
|
|
Term
| Differential Gene Translation |
|
Definition
Expression of a microRNA complementary to a gene
or mRNA that inhibits expression of the protein |
|
|
Term
|
Definition
Mosaic Model
In most invertebrates
– Transcription factors are already present in different regions of egg cytoplasm
– Cells cannot change fate if a blastomere is lost |
|
|
Term
| Conditional Specification |
|
Definition
Regulative
Model
– Mostly in vertebrates
– Products from transcription factors from cells interact with neighboring cells
– Allows cells to acquire different functions
o Embryo is able to develop normally even when some portions
are removed or rearranged |
|
|
Term
|
Definition
| Transcriptional factor and cellcell adhesion molecule |
|
|
Term
|
Definition
– B-catenin localized throughout
– Dsh is localized in the vegetal
cortex
– Glycogen Synthase Kinase
(GSK-3) is also present |
|
|
Term
|
Definition
– GSK-3 targets Β-catenin for
degradation
– Dsh inhibits GSK-3
– Dsh prevents degradation of
Β-catenin |
|
|
Term
|
Definition
Large micromeres or primary mesenchyme are autonomously
specified—they will migrate and then develop into skeletogenic mesenchyme that
differentiates into larval skeleton
n
• These same cells also specify neighboring cells by conditional (regulative) specification
to form endoderm that will invaginate into the embryo
they are specified but not totally committed
Micromeres can
induce presumptive
endoderm to form a
pluteus larva |
|
|
Term
Differentiation by Maternal Factors in
Sea Urchin |
|
Definition
Prior to gastrulation (16-cell stage), embryonic cells are specified and determined by specific
regulatory factors
• Inherited maternal factors (i.e. Β-catenin and Disheveled) in micromeres activate
the endomesoderm Gene Regulatory Network (GRN) at 16-cell stage
o Activation of Pmar by Β-catenin and Otis eventually leads to skeleton-forming genes in
micromeres
o Inactivation gives rise to endoderm plus pigment cells, muscle cells, coelomic cells |
|
|
Term
| Regulative Differentiation |
|
Definition
Regulative Model (Conditional Specification)
– Development depends upon interactions between neighboring cells
– Cells /tissues surrounding environment can influence its developmental
fate –usually by a diffusable biochemical molecule called a morphogen
• Morphogen can determine cell fate by its concentration
• Morphgens can be transcription factors produced within cells |
|
|
Term
| • Cell Adhesion and Migration |
|
Definition
where cells create new
shapes or structures through cell affinity and cell movement |
|
|
Term
| Cell Signaling or Induction |
|
Definition
where one group of cells
influences development of an neighboring group of cells |
|
|
Term
|
Definition
Movement of epithelial and
mesenchymal cells
(Epithelial to Mesenchyme
Transition or EMT) |
|
|
Term
|
Definition
| Seals neighboring cells in an epithelial sheet |
|
|
Term
|
Definition
—Joins an actin bundle in one cell to a similar bundle in neighboring
cell |
|
|
Term
|
Definition
| anchors the intermediate filaments in one cell to those in a neighboring cell |
|
|
Term
|
Definition
| Allows passage of small water soluble molecules between cells |
|
|
Term
|
Definition
| Anchors intermediate filaments in a cell to the basal lamina |
|
|
Term
| Integrins, selectins and CAMs |
|
Definition
(immunoglobulin-like adhesion molecules) provide a
mechanism for cell-cell recognition |
|
|
Term
|
Definition
Loss of E-cadherin
Cell shape changes plus movement driven by Rho GTPases |
|
|
Term
|
Definition
– Epithelial Cells
• Ectoderm—supplies positional
information to skeletogenic cells that
enable PMCs to produce a skeleton
• Oral ectoderm produces stomodeum
– Mesenchyme Cells
• PMCs
– Produce calcium carbonate
skeleton
• SMCs
– traction exerted by filopodia from
secondary mesenchyme cells
(SMCs) produces elongation of
the archenteron during sea urchin
gastrulation |
|
|
Term
|
Definition
Epithelial Cells
– Epithelial cells are
arranged in one or more
layers that form part of a
covering or lining of a
body surface
– Tightly connected to each
other in sheets or tubes |
|
|
Term
|
Definition
During gastrulation, the mesenchyme can become bone, cartilage,
connective tissue, adipose tissue, and other components of the adult body |
|
|
Term
| Townes and Holtfreter 1955 |
|
Definition
• Embryonic cells dissociated in vitro will reaggregate then “sort-out”
spontaneously into distinct layers reflecting their origin
• Differential Cell Affinity Hypothesis: Spontaneous sorting of cell
types in vitro and in vivo reflects differences in adhesion across cell
types |
|
|
Term
|
Definition
| DRAW THAT BAD BOY FROM MEMORY! |
|
|
Term
|
Definition
Functions as adhesive substrate
-tracks to direct migratory cells
-concentrations gradients for haptotactic migrations
provides structure
-defiens tissue boundaries
-provides integrity and elasticity to developing organs
-degraded by invasive cells during development and disease
presents growth factors to their receptors
-controls spatial distrubution of ECM-bound surface molecules
-facilitates cross talk between grown factor receptors and ECM receptors
sequesters and stores growth factors
-allows for spatio-temporal regulation of factor release
-organizes porphogen gradients
-mediates release of factors in the presence of appropriate cell-mediated forces or proteolytic degradation
senses and tranduces mechanical signals
-defines mechanical properties permissive/instructice to cell differentiation
-activates intracellular signalling through interaction with cell-surface receptors
-engages cytoskeletal machinery and synergizes growth factor signalling |
|
|
Term
|
Definition
• high-molecular
weight(~440kDa)
glycoprotein
• binds to membranespanning receptor
proteins called integrins
• also binds extracellular
matrix components such
as collagen, fibrin, and
heparin sulfate
proteoglycans |
|
|
Term
| Fibronectin Structure and Function |
|
Definition
• dimer connected by disulfide bonds at c-terminus
• cell binding segment is RGDS
o RGDS = arg-gly-asp-ser
o RGDS binds to cell surface integrin
• domains bind to other ECM proteins
o collagen
o proteoglycan
Function:
• cell adhesion
• differentiation
• minor contributor
to basal laminae |
|
|
Term
|
Definition
type 1,2,3 cross straited
-showing overlapping packing in individual collagen molecules
type 4 fine unstraited
-sheet-like supportive meshwork
-mature basal laminae
-tracks for embyonic migration
-barriers for cell migration
type 5-12
-smaller diamer fibers than 1-3,
-no striation |
|
|
Term
|
Definition
cross-shaped glycoprotein
-3 polypeptides a,b1,b2
-carbohydrate(13%) by weight
-separate binding domains
-collagen 4
-heparin
-heparin sulphate
-cell binding |
|
|
Term
|
Definition
Function:
• trap water
o resistant to
compression
o return to original shape
• occupy space
• cell adhesion—embryonic
migration |
|
|
Term
|
Definition
receptor that mediates the
attachment between a cell and
the extracellular matrix(ECM)
during signal transduction
– extracellular side--can bind
to laminin and fibronectin
through the RGD binding
site
– intracellular side—binds to
talin, vinculin and
α actinin of which connects
to actin
• involved in cell signaling,
shape, and motility |
|
|
