MCD BIO 138 Lecture Notes - Lecture 16: Primitive Streak, Morpholino, Gastrulation
13 Oct 2020
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Recap: formation of maternal factors are important for specifying endoderm, maternal tf veg-t (also involved in mesoderm patterning) Morpholino against veg-t -> no endoderm (and mesoderm) In amphibians: endoderm specified maternally prior to gastrulation movements. During gastrulation: involution moves endoderm into interior of embryo. Endoderm & mesoderm specified during gastrulation (not maternally determined) Passage thru primitive streak -> certain genes segregate endoderm. Mutation disrupting ciliary function: mutation leads to randomization of organ location in mice and humans e. g. mirror reversals, gained attention via human disorders, can be caused by mutation in dynein. Endoermal pattenring -- ap: progressive development, endoderm divided into broad regions (foregut, midgut, hindgut) (think gap genes in drosopihla; conservation of function, gradient of factors essential for patterning ap axis e. g. wnt gradient. Lof expt: tracking a gene expressed in stomach but not in intestine -> tracking if tissues taking on stomach characterstics, cdx2 deleted from endoderm, result: intestine that normally doesn"t express stomach gene starts expressing it.
