| Name: | notochord |
|---|---|
| Synonyms: | notocord |
| Definition: | Rod-like principal supportive element of the embryo and larva, present in the midline just ventral to the neural tube, and differentiating during the segmentation period to form large vacuolated epithelial cells and a surrounding sheath of fibrous and elastic layers. Layering of the sheath may differ in structure, thickness and development among groups; in cypriniforms there are actually three very thin layers to the sheath. A functional, well developed notochord is present throughout life in certain basal fish groups but not in cypriniforms. |
| Ontology: | Anatomy Ontology [ZFA:0000135] |
| Name: | rough endoplasmic reticulum |
|---|---|
| Synonyms: | RER, rough ER |
| Definition: | The rough (or granular) endoplasmic reticulum (ER) has ribosomes adhering to the outer surface; the ribosomes are the site of translation of the mRNA for those proteins which are either to be retained within the cisternae (ER-resident proteins), the proteins of the lysosomes, or the proteins destined for export from the cell. Glycoproteins undergo their initial glycosylation within the cisternae. |
| Ontology: | GO: Cellular Component [GO:0005791] QuickGO AmiGO |