Even-skipped gene

In embryonic muscle development in Drosophila, three types of signals converge to promote differentiation (see Figure 15-40). These signals induce the production of three transcription factors that combine with two tissue-specific transcription factors to activate transcription of the even-skipped gene, which marks a muscle precursor cell. 

Pair-rule genes—define seven bands runt (runt) hairy (h) fushi tarazu (ftz) even skipped (eve ) paired (prd) odd paired (opa)... 

Fujioka, M., et al. 1999. Analysis of an even-skipped rescue transgene reveals both composite and discrete neuronal and early blastoderm enhancers, and multi-stripe positioning by gap gene repressor gradients. Development 126 2527-2538. 

Kriippel acts as a gap gene regulating expression of hunchback and even-skipped in the intermediate germ cricket Gryllus bimaculatus. Dev Biol. 2006 Jun 15 294(2) 471-81. Epub 2006 Apr 17. 

Exons and introns are far more than a curiosity. In protein synthesis (see below) the introns must be eliminated in a process known as splicing the introns are spliced out, or removed, and the exons are joined together as required to produce a coherent message for protein structure. Exons can be spliced out (removed or skipped over) as well. The upshot of all this is that one gene apparently coding for one protein can, in fact, code for several or even many. To see how this works, let s consider an... 

---