Question

What would be the consequence of ectopically expressing hoxd10 and hoxd11 throughout the developing mouse limb bud?

Answer 1

Hox genes are: Hoxd9,10,11,12 and 13. Hox genes are responsible for limb bud formation. Hoxd9 influences thumb, Hoxd9 and 10 index fingers and so on. 
Hoxd10 has ectopic effect on the development of the mouse limb bud index finger. As  a consequence index finger in formed in place of thumb.