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48 Cards in this Set
- Front
- Back
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? is a description of morphologic events
Ex: gross changes in form |
Classic Embryology
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? is the molecular events responsible for morphologic changes
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molecuar embryology
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? events commit a cell to a specific fate.
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Molecular events
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What are the 2 stages of Commitment?
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Specification
Determination |
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? is the capacity for tissue specific differentiating in a NEUTRAL environment
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Specification
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? is the nearly irreversible commitment to tissue-specific differentiation irrespective of environment
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Determination
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What are the mechanisms of Cell commitment?
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Autonomous Specification
Conditional Specification |
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? is when determinants present int he zygote cytoplasm segrate into different blastomeres during cleavage.
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Autonomous Specification
aka Mosaic Development |
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P granules (germ cell specification) is an example of what type of specification?
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Autonomous specification
aka mosaic development |
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? is where cell fate depends on the cells environment and cell-cell interaction.
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Conditional Specification
aka Regulative Development |
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What is the type of development that is predominated in human development is?
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Regulative development
(conditional specification) |
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? are considered to be MASTER REGULATORS of development.
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Transcription Factors
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What do transcription factors do?
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Interact with DNA to regulate a cascade of genes including additional transcription factors
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? is developmentally important family of transcription factors.
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Homeodomain Proteins
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? is the ability to transform one body part into another .
(ex: antenna into legs) |
Homeosis
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? is 60 amino acid DNA binding domain that is encoded by a 180 base pair Homeobox.
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Homeodomain
(protein) |
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What encodes for the homeodomain 60 amino acid DNA binding domain?
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Homeobox (180 base pair)
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What are examples of transcription factors?
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homeodomain proteins
-HOX -Nkx Lim |
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Which subfamily of homeodomain proteins is the Basic Body Plan under?
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Hox
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Which subfamily of homeodomain proteins is the Heart Development associated with?
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Nkx
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What subfamily of homeodomain proteins is CNS and Limb development associated with?
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Lim
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EARLY expression establishes cranial caudal SEGMENT IDENTITY ;; then reutilized to establish organ morphology
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Hox
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Humans have ? incomplete sets of Hox genes on ? separate chromosomes.
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4 incomplete sets of Hox genes
4 Separate chromosomes |
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What are the 2 hypotheses of The Hox Code?
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Posterior Predominance
Hox Code (overlapping expression) |
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? is the expression of posterior genes in a given region predominates over more anterior genes in specifying segment identity.
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Posterior Predominance
(hox code) |
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Segment identity is based on the combination of Hox gene expression in the given segment.
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Overlapping expression
(hox code) |
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What are the 4 ways in which molecules regulate cell commitment and development?
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Transcription factors
Ligand Mediated Transcription Factors / Nuclear Receptors Surface Receptor Mediated Regulation Molecules that Modify Transcriptional Regulation |
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Give examples of Ligand Mediated TF / Nuclear Receptors.
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Estrogen, Progesterone, other steroids (LIPOPHILIC molecules bind to a nuclear receptor/TF)
Retinoic Acid (RA) |
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Vitamin A derivative.
Tight control of expression and activity |
Retinoic Acid (RA)
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On what receptors do retinoic Acid work on?
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act via NUCLEAR RECEPTORS RAR and RXR
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RAR/RXR Ligand bound receptors bind to ? within responsive genes to regulate transcription
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RA response elements (RARE)
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What transports Retinoic Acid into the nucleus?
allowing it to bind with RAR/RXR |
CRABP
cellular retinoic acid binding protein (its a morphogen sink) |
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What are Surface Receptor Mediated Regulation
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Growth factors
Secreted Morphogens -Sonic Hedgehog (Shh) |
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Sonic hedgehog (Shh) binds to a surface receptor ?
This causes a release of Surface Protein ? to activate signal transduction Activates Transcription factor ? within the nucleus |
Patched (Ptc)
Smoothened (Smo) Gli (transcription factor) |
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Why is Sonic hedgehog (Shh) important?
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Neural Tube Formation
limb development left-right sidedness GI tract feather/hair formation |
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? bind to the receptor mediates signal transduction
Activates ? in the nucleus |
Growth Factors
Transcription factors |
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What are the function of Growth Factors?
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Induce or Inhibit growth/differentiation of local populations of cells in which specific receptors have been induced.
Promote both cell growth and programed cell death (apoptosis) |
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Give examples of Transforming growth Factor β
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Bmps ---> apoptosis of cells :: prevents webbing from occurring in fingers
Gdf |
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What inhibits Bmp?
This causes webbing between fingers to occur. |
Gremlin
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Important organizing and patterning factors that have also been linked to TUMORIGENESIS.
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Wnt proteins
(growth factor) |
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Increased levels of Wnt proteins may be an indicator of?
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Tumorigenesis
tumor growth |
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True or False
Many molecules exist that modify the TRANSCRIPTIONAL REGULATION of the ways that molecules regulate cell commitment and development |
True
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True or False
If anything goes wrong with one of the MODIFYING FACTORS in a pathway MUTATION WILL ALWAYS OCCUR |
True
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True or False
Enzymes are most involved with FUNCTION OF DIFFERENTIATED CELL rather than MORPHOLOGY. |
True
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What is the effect of Collagen and Proteoglycans in cell differentiation?
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Forms connective tissue scaffolding
Helps with Cell Migration |
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True or False
Many of the developmentally important molecules are used MULTIPLE TIMES in development for morphogenesis of different body parts. |
True
ex: Shh is critical for Neural tube formation and differentiation, limb development patterning, and establishment of hair follicles. |
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How is Shh expression regulated?
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multiple enhancer elements respond to SITE SPECIFIC and STAGE SPECIFIC cues.
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? describes the capacity of one cell or tissue to influence other cells.
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Induction
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