The emerging column of cells topples over called ‘the slug’.

TLS Online TPP Program

#Id: 172

#Unit 5. Developmental Biology

Combination of Pax6, Sox2, and L-Maf in the ectoderm is needed for the production of the lens and the activation of lens-specific genes i.e. δ-crystallin.

TLS Online TPP Program

#Id: 173

#Unit 5. Developmental Biology

If Pax6 is lost (fruit flies, frogs, rats, humans) complete loss or reduction of the eyes

TLS Online TPP Program

#Id: 174

#Unit 5. Developmental Biology

Two major modes of inductive interaction:

 Instructive interaction

 Permissive interaction

TLS Online TPP Program

#Id: 175

#Unit 5. Developmental Biology

In instructive interaction, 

a signal from the inducing cell is necessary for initiating new gene expression in the responding cell.

TLS Online TPP Program

#Id: 176

#Unit 5. Developmental Biology

Instructive interaction

It occur where the responding cell has a choice of fates and will follow one developmental pathway following induction and an alternative pathway in absence of the inductive signal. 

TLS Online TPP Program

#Id: 177

#Unit 5. Developmental Biology

In Permissive interaction

The responding tissue has already been specified and needs only an environment that allows the expression of these traits.