BIOSC 0160 Lecture Notes - Myod, Skeletal Muscle, Homeobox
Document Summary
Once it is expressed, fate is determined. Stimulates transcription of other muscle-specific transcription factors. If myod isn"t expressed, none of the other things can happen. Thus, it is a master regulatory gene. Pattern formation: establishment of precise spatial relationships between parts during development, axis specification, occurs via maternal effect genes (a. k. a. egg polarity genes, eg. Necessary for the proper anterior to posterior axis. Operates via a concentration gradient: segmentation, occurs via segmentation genes, bicoid genes turn on gap genes. Gap genes establish basic antero-posterior subdivisions: gap genes turn on pair-rule genes. Pair-rule genes map out the modular pattern in pairs of segments. Mutations here result in loss of either odd or even segments: pair-rule genes turn on segment-polarity genes. Segment-polarity genes set up the axis of each segment (more specific to the 14 segments: homeobox genes, master regulatory genes for parts are homeotic genes, mutations cause really weird phenotypes antero-posterior each of.
