BIOL 303 Lecture Notes - Lecture 22: Corpus Allatum, Limb Bud, Sonic Hedgehog
27 Apr 2016
School
Department
Course
Professor
Document Summary
S19 pattern formation along ap via shh (zpa produces shh): Graph1 : shh [ ] vs ap axis in chick limb bud: there"s a decrease in shh gradient p a. High shh (posterior) = high gli3 activator ,,, low shh (anterior) = high gli3r repressor. Graph2 : gli3/gli3r along ap: decrease in ratio as p a . So morphogen gradient (shh) is translated into gradient of tf (activator and repressor) resulting in pattern formation along ap in chick limb bud(depending on location of cells along. Gli3 and gli3r have opp effects on exp of downstream genes: gli1, ptc, myc,igf2, etc. So shh gradient = pattern formation along ap in chick. S20 in mouse embryo , shh is also responsible for pattern formation along ap. However not only the [ ] of shh is imp, but the time of exposure to shh is also imp:
