W3 Flashcards
What is self-renewal?
Stem cells can go through a number of divisions without changing their identity.
What is differentiation?
SC of daughter is set on a path of differentiation, are able to renew and may still be able to change it’s fate.
What are some aspects of terminally differentiated cells?
The are usually unable to self-renew.
Differentiation cannot be altered.
What are “knock-out mice”?
Genetically engineered mice using stem cells.
What technique was used to generate Dolly?
SCNT (somatic cell nucleus transplantation into oocyte)
What are the steps of zygote formation?
Fertilization
- sperm fuses with mature oocyte which is arrested at second meiotic divisions.
- Sperm fusion triggers completion of meiosis and the zygote is formed.
Describe the pronuclear stage.
Maternal and paternal pronucleus (haploid) are still separate. They migrate and become closely opposed.
What are the stages after fertilization?
- 2, 4, 8 cell stage
- Morula
- blastocyte.
What are the parts of the blastocyte and what do they form?
- outer layer - trophectoderm - forms extra-embryonic tissue (placenta)
- blastocoel (fluid filled)
- Inner cell mass (ICM) - becomes the new animal.
What does gastrulation develop.
3 germ layers
ectoderm, mesoderm, endoderm
Isolation experiments
used to evaluate to what extent the development fate has already been specified.
- cells removed
- placed in in vitro culture
- see what type of cells are developed.
What embryological approaches are used to analyse the restriction of development potency?
- fate mapping
- isolation experiments to analyse specification
- transplantation expriments to analyse determination
What is induction?
The influencing of development fate by signals from another cell or cell group.
Spermann and Mangold experiment.
replaced implanted extra dorsal lip in blastospore. frog with 2 spinal cords developed.
What are the stem cells in bone marrow?
multipotent hematopoietic stem cells. Produce: 1. bone marrow - 2. bone marrow produces blood 3. some blood cells produce tissues