BIOL 202 Lecture Notes - Lecture 32: Point Mutation, Antigen, Chromatin
Document Summary
E. g. ubx halter, mutants grow wings instead (a forced expression: appendages established by dll gene (not expressed in abdominal segments) Dll in abdomen is repressed by ubx and abd-a (both are hox genes, mimic dll cis- acting regulatory element) Ubx mutant can be complemented by abd. Repression of dll also require at least one segment polarity genes (spl and en: mammals have duplicated hox genes (4 clusters) E. g. knock out of hoxa11 in mice makes longer vertebrae. 41 protein, worm doesn"t enter l4 at all. Immune system and autoimmune diseases: antibody against body own antigen: humoral immunity (b cells and antibodies) B diverse start with non-specific, then cells that may targets body own cell get destroyed. Binding of antigen triggers b cell division. Proliferation and maturation of cell makes plasma cells and starts producing antibodies. Memory b cells have secondary response (rapid: cellular immunity (t cell receptor and bind to cells to kill)
