ZOO 3050 Lecture Notes - Lecture 7: Fate Mapping, Cell Lineage, Blastomere

• School: University of Guelph
• Department: Zoology
• Course: ZOO 3050
• Professor: Todd Gillis

Document Summary

Sea urchin cell lineage: (cid:862)conditional cell fate(cid:863, also referred to as regulative or indeterminate, surface of the egg is (cid:862)equal(cid:863, blastomeres can be separated and each will produce a complete larva. Snail cell lineage: (cid:862)autonomous cell fate(cid:863, also referred to as mosaic, each part of the surface of the embryo leads to specific structure in the larva/adult. Fate maps: diagrams of what becomes of each region of embryo during development, already determined at this early stage. Illustrate which region of embryo gives rise to different germ layers during gastrulation. Sea urchin fate map: most of embryonic cell fates are specified by the 64-cell stage (6th division, cell are not irreversibly committed, blastomeres produce pluripotent cells that can give rise to other cell types. Isolation of blastomeres at 4 cell stage: each blastomere developed into a complete larva, conclusion: conditional specification. Ingress into blastocoel: skeletogenic mesenchyme cells of sea urchin embryo, specified autonomously, become skeleton of sea urchin larva.