2.24 Differentiation, Development and Stem Cells Flashcards
Embryonic development has to deal with 5 issues
Growth Cell differentiation Regional specification Morphogenesis Developmental time
Increase in cell number and size and proportion among parts
Growth
Cell specialization
Cell differentiation
From featureless blastula or blastoderm to body parts via determinants at different positions of the fertilized egg and later embryonic inductions
Regional specification
Cell and tissue movements that give rise to 3D shape and organization
Morphogenesis
Coordination of developmental process in time
Developmental time
What a cell will become in the course of normal development
Cell fate
What range of cell types a cell can become
Developmental potential or potency
A cell has progressive restrictions on its developmental potential, even before phenotype change
Determination of cell fate
Stem cell types by plasticity
Toripotent
Pluripotent
Multipotent
Can give rise to all cell types as well as an entire new individual
Toripotent
Can give rise to all cell types
Pluripotent
Can give rise to a limited range of cells within a tissue type
Multipotent
Stem cells by source
Embryonic stem cells
Adult stem cells
Engineered cells
Not necessarily adult, but after birth
Adult stem cells
Umbilical cord tissue
Bone marrow cells
Adult stem cells
iPS
Trasdifferentation
Engineered cells
All our cells have the same genome (barring our rearranged genes for antibodies and T-cell receptors)
Our cells are MZ twins of each other
True or false
Differential gene expression occurs despite identical genome
True
True or false
Methylation is lost and gained during embryonic development
True
Responsible for imprinting of genes
Epigenetic differences
True or false
When epigenetic programming goes awry, disease may result
True
Controls for gene expression
Chromatin structure
Transmembrane molecules for cell adhesion and signaling
Gene regulatory proteins
True or false
Cell differentiation happens before cell determination
False
Cell determination happens before differentiation
Two major mechanisms for cell determination
Asymmetric segregation of cellular determinants
Inductive signaling among cells
True or false
Proteins and RNA are equally segregated during cell division
False
They are unequally segregated
Inductive signaling has 3 major mechanisms
Diffusion
Direct contact
Gap junctions
Diffusible signal released from one cell interacts with receptor on target cell
Can work at a distance
Diffusion
Interaction of transmembrane proteins on each cell results in production of a signal
Direct contact
Movement of signal between connected cells
Gap junction
Cell-to-cell contact can lead to __ and ___
Lateral inhibition
Cell diversification
Sonic hedgehog acts as a __ in chick limb development
morphogen
Death depends on expression of the ___ and ___ genes in the absence of __ expression–all in dying cell itself.
ced-3
ced-4
ced-9
3 germ layers
Endoderm
Mesoderm
Ectoderm
Most internal germ layer
Forms the lining of the gut and other internal organs
Endoderm
Most exterior germ layer
Forms skin, brain, the nervous system and other external tissues
Ectoderm
Middle germ layer
Forms muscle, the skeletal system and the circulatory system
Mesoderm
To move during the process of ingression, the cells must undergo ___
Epithelial to mesenchymal transition
Classic pluripotency tests
Teratoma
Chimera
Molecular pluripotency tests
DNA methylation patterns
Gene expression patterns
A tumor of different tissues of all 3 germ layers
Teratoma
A single individual made of genetically distinct cells
Chimera
It is also possible to directly reprogram one cell type to another without a pluripotent intermediate. Technique, called ____, extracted mRNA from a heart cell and transferred them to host cells
Transcriptome induced phenotype remodelling
Classic example of adult pluripotent stem cells
Hematopoietic stem cells
True or false
Stem cells from amniotic fluid are also pluripotent and unlike embryonic stem cells, do not form teratoms
True
Same person is donor and recipient
Autologous transplantation
From a different donor individual to a recipient
Allogeneic trnsplantation
From an animal donor to a human recipient
Xenotransplantation
True or false
Human liver buds made from iPS cells are functional when transplanted into mice
True
Induction of undifferentiated inducible progenitor cells that are not yet committed to osteogenic lineage to form osteoprogenitor cells
Osteoinduction
Guidelines re cell therapies: prohibited
Creation of embryos for research purposes
Human embryonic stem cells and their derivatives for human treatment and research
Aborted human fetal cells and their derivatives for human treatment and research
Plant parts labeled as stem cells
Guidelines re cell therapies: restricted
Genetically altered human adult stem cells for human treatment
Genetically altered human umbilical cord stem cells for human treatment
Adipose derived human stem cell
Any human cells, tissues and cellular and tissue-based products that are subjected to genetic manipulation
Live animal embryonic, fetal or adult stem cells in parenteral form for human administration
Guidelines re cell therapies: allowed
Adult autologous human stem cells, including those that had gone through basic processing but not genetic modification
Adult allogeneic stem cells, including those that had gone through basic processing but not genetic modification. Requires HLA compatibility testing and infectious screening similar to organ transplants and blood transfusions
Human umbilical cord stem cells, including those that had gone through basic processing but not genetic modification
Human organ-specific cells, with similar conditions as organ transplants and blood transfusions