epidermis
the epithelial part of the skin
epithelium
a tissue type in which cells are arranged as a single or multilayered sheet lying on a basement membrane
mesoderm
the middle of the three germ layers
germ layers
the ectoderm, mesoderm and endoderm
ectoderm
the outer of the three embryonic germ layers
endoderm
the inner of the three germ layers
neural plate
flat sheet of neuroepithelium that will roll up to form the neural tube of a vertebrate embryo
vertebrate
Wirbeltiere
determinant
(=cytoplasmic determinant) substance localized to part of an egg or blastomere that causes the cells that inherit it to acquire a particular developmental commitment
zygote
fertilized egg, strictly after the stage of fusion of male and female pronuclei
somatic cells
all cells of an organism that are not the germ line; may be collectively referred to as the soma
germ line
the cell lineage that will form the gametes, comprising the primordial germ cells, spermatogonia and oogonia, together with other clonal progeny such as nurse cells. The germ line is often formed by the action of cytoplasmic determinants
centrosome
an organelle that serves as the main microtubule organizing center (MTOC) of the animal cell, as well as a regulator of cell-cycle progression. The centrosome provides structure for the cell.
cortex
outer region of a cell, especially an egg or oocyte, comprising a few microns thickness beneath the plasma membrane
oogenesis
the development of oocytes (Eizellen)
Dynein and Kinesin
motorproteins that travel along the microtubuli
Karyokinesis
separation of chromosoms / nuclei via Mikrotubuli: Inhibition by Nocodazol or Colchizin
Cytokinesis and Septins
separation of daugther cells via actinmicrofilaments: Inhibition by Cytochalasin B
Septins form ringstructure to cut the cells (also septins help at blebbing, form bases for membrane proteins / receptors or for Cilium or Annulus)
Cytokin
werden Proteine bezeichnet, die das Wachstum und die Differenzierung von Zellen regulieren. Sie sind eine Gruppe von Peptiden, die vor allem die Proliferation und Differenzierung von Zielzellen einleiten oder regulieren.
autocrine
endocrine
paracrine
syncytial blastoderm
One single cell, multiple nuclei
Forms in early drosophila developement after Cleavage phase (first 12 rapid cell divisions)
Cellularization
Ending the syncytial blastoderm
- Membrane starts to fold inwards between nuclei
- Eventually, formation of a cellular blastoderm : One nucleus per cell!
midblastula transition
After the cellular blastoderm is formed:
• Nuclear division becomes progressively slower
• Divisions become asynchronous
• Zygotic gene transcriptions starts!
• Cells gain motility
—> start of gastrulation: Morphogenetic movement that results in formation of the three germlayers
Zuletzt geändertvor einem Jahr