BIOL 401 Lecture Notes - Lecture 19: Neural Crest, Sonic Hedgehog, Pax6
30 Apr 2017
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Ligands bind to receptors on a cell then are transduced, which is the method for development: membrane bound receptors are not transducers, ligand doesn"t pass into cell ~ bind to receptor and trigger signals outside of the cell. Different stages of development trigger ectoderm, mesoderm, and endoderm, then certain cells will begin giving off different signals for differentiation: different concentrations of ligands cause differentiation. Development of sexes (14:00): ducts develop into testes or ovaries: wollfian testes, degenerated in females, mullerian ovaries, degenerated in males (notes from 20:00 because computer froze) Oogenesis: oogonium: somatic cells that develop into eggs. Primary oocyte with yolk in the liver of developing organism. Vitellogenin/vldl taken up by lr8 receptor in yolk. First division occurs at this stage to form a secondary oocyte. Here development will be arrested for up to 50 years (this is the stage eggs are stored in ovaries). Embryonic development (slides 12: blastula (slide 12-13): most important part is spemann organizer.
