Cell-cell communication Flashcards
components of signal/response system must include
- signal
- receptor
- mechanism to translate/transport signal
- mechanism to translate signal to a simulation of gene expression
communication for short distances like in neighboring cells, direct contact
Juxtacrine signaling
communication for long distances where there is usually a secretion of proteins in ECM
Paracrine signaling
secreted from a cell designated to communicate a response
signaling proteins
proteins that bind signaling proteins
receptors
binding of same type of receptors
homophilic binding
binding of different types of receptors
heterophilic binding
True or False: Development depends on the precise arrangement of tissues and cells
true
True or False: organ construction is precisely coordinated in time and space
True
True or False: arrangement of cells and tissues does not change over time
False; change over time
interaction at close range between two or more cells or tissues with different histories and properties
induction
tissue that produces a signal that changes cellular behavior
inducer
tissue being induced; target tissue
responder
are proteins made by a cell/group of cells that alter behavior and differentiation of adjacent cells
paracrine factors
difference of paracrine factors with hormones
Paracrine factors are secreted in ECM while hormones are secreted in bloodstream.
True or False: the target tissue can be incapable of responding
False; must be capable of responding
ability of a cell or tissue to respond to a specific inductive signal
competence
tissue thickening
lens placode
induced in head ectoderm by close contact with neural (brain tissue)
lens placode
developing lens induces brain to form _______
optic cup
True or False: competence is actively acquired (and can also be transient)
True
Where is Pax6 expressed during lens induction?
head ectoderm
True or False: Pax6 is expressed in other regions of ectoderm
False; it is only expressed in head ectoderm and not in other regions of surface ectoderm
a competence factor for lens induction
Pax6
what does BMP4 mean?
bone morphogenic protein 4
induces Sox2 and Sox3 transcription factors
BMP4
induces L-Maf transcription factor
Fgf8
What does Fgf8 mean?
fibroblast growth factor 8
multiple induce tissues operate on a structure
stepwise induction
1st inducer for frog lens
pharyngeal endoderm & heart-forming mesoderm
2nd inducer for frog lens
anterior neural plate
inducing signal for ectoderm Pax6 synthesis
anterior neural plate
signal from inducing cell is necessary for initiating new gene expression in the responding cell
instructive interaction
without the inducing cell, the responding cell is not capable of differentiating
instructive interactions
Instructive interactions ______ the cell’s developmental options
restrict
responding tissue has already been specified; needs only an environment that allows the expression of those traits
Permissive
tend to regulate the degree of expression of the remaining developmental potential of the cell
permissive
sheets or tubes of connected cells
epithelia
True or False: epithelia originate from any cell layer
True
loosely packed. unconnected which are derived from mesoderm or neural crest
mesenchyme
where is the mesenchyme derived?
mesoderm & neural crest
True or False: all organs consist of an epithelium and an associated mesenchyme
True
True or False: many inductions involve interactions between epithelia and mesenchyme
true
initiates gene activity in epithelial cells
mesenchyme
where does mesenchyme initiate gene activity
epithelial cells
source of the mesenchyme (inducing tissue) determines the structure of the epithelial derivative
Regional specificity
epithelial response is limited to genomic capability
genetic specificity
response to signals at the molecular level
signal transductiion
What are the Paracrine Factor Families
fibroblast growth factor
hedgehog family
Wingless family
TGF-B superfamily
meaning of TGF
transforming growth factor
enzyme that phosphorylates a protein
kinase
