Introduction Flashcards
Human embryonic development takes ___ weeks
8
Gradient-dependent cell fate
Variations on inductive signaling
Major families of developmental growth factors
The only major small molecule developmental signal
Retinoic acid
All the rest are proteins.
Why have so many families of developmental growth factors?
Cell lineage is ___-dependent
Cell lineage is history-dependent
In other words, responsiveness to any given growth factor is NOT a state function.
Cross-repression
Responses to motility and orientation-inducing factors
Germ lineage tree
Epithelial vs Mesenchymal Cells
EMT
EMT in gastrulation
Ectodermal cells undergo EMT to form mesendodermal cells.
Mesendodermal cells may decide to remain mesenchymal, and thus form the mesoderm, or to undergo a MET, and form the endoderm.
Levels of stem cell potency
Cell reprogramming
Averts the need to make iPS cells.
Ovum
Sperm
Sperm capacitation
Occurs when sperm enters the female reproductive tract
Process of removal of glycoproteins from the sperm membrane surrounding the acrosome such that the acrosomal surface is more available to interact with the ovum membrane.
What is the function of the cortical reaction?
To prevent polyspermy
Upon fertilization, the ovum undergoes. . .
Meiosis II
The polar body also undergoes meiosis II. At this point, both polar body copies of the genome and one maternal ovum copy of the genome will be lost, leaving a haploid maternal genome and a haploid paternal genome.
How many pronuclei does a fertilized ovum have?
Two: One maternal, one paternal.
However, this state does not last long, as the fertilized ovum will quikly undergo mitosis to form a 2-cell blastomere.
Development Progression
Zygote
Blastomere
Morula
Blastulation
-blast
rapidly dividing cell
Post-fertilization spacial progression
Implantation
Syncytium
Group of cells with many nuclei unseparated by any plasma membranes.\
Extremely beneficial for nutrient transport.
Development of trophoblast
~1 week post-fertilization.
2 Week Stage
Completed Implantation
Epiblast -> amniotic sac
Hypoblast -> embryo and yolk sac
~ 2 weeks
2 layers
2 cavities
The ___ and ___ are the primary organizers of the body.
The primitive node and primitive streak are the primary organizers of the body.
Gastrulation
Ectodermal cells under go an EMT, migrate through the primitive streak, and form the primitive mesoderm and endoderm.
The Oropharyngeal membrane will become the oral cavity and esophagus, the Cloacal membrane will be come the urethra, vagina, and anus.
_____ is the only pluripotent layer of the gastromere.
The ectodermal epiblast is the only pluripotent layer of the gastromere.
Pioneer Transcription Factors are basically always ___.
Pioneer Transcription Factors are basically always Master Trascription Factors.
Homeostasis primarily utilizes ___ feedback while development primarily utilizes ___ feedback.
Homeostasis primarily utilizes negative feedback while development primarily utilizes positive feedback.
Four Yamanaka Factors
OCT 2
SOX 4
c-Myc
KLF4
