BIOL303 Lecture Notes - Lecture 7: Paracrine Signalling, Cell Signaling, Homeobox
5 Mar 2015
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Document Summary
Tfs or components of the cell/cell signalling machinery: segment polarity genes reinforce pattern of parasegment gene expression and determine cell fate within each segment (now have 14 distinct bands) If you divide each segment into an anterior and posterior half, a parasegment is the anterior of one segment and posterior of an adjacent segment. There are 14 parasegments: there are 14 parasegment that alter between ftz and eve. Within each parasegment, whether it be ftz or eve, expression goes down from anterior to posterior. Expression patterns of engrailed and wingless (en and wg) come through positive/negative regulation by pair rule genes. So within the anterior boundary of each parasegment, en is expressed, and in the posterior boundary wg is expressed. So within each segment, both eve and ftz are expressed. In engrailed cells, there is a protein factor called hedgehog which binds to receptors on anterior wingless cells and maintains wingless expression.
