Haldane’s rule: hybrid sterility or hybrid inviability is often limited to the heterogametic sex. (The heterogametic sex is the one with two different sex chromosomes, while the homogametic sex has two sex chromosomes of the same type).

TLS Online TPP Program

#Id: 9610

#XL - T Zoology

Insulin receptor, form disulfide-linked dimers in the absence of hormone.

TLS Online TPP Program

#Id: 9611

#XL - T Zoology

Binding of ligand to predimerized but inactive RTK alters the conformation of the dimer in such a way that the receptor’s kinase becomes activated.

TLS Online TPP Program

#Id: 9612

#XL - T Zoology

TLS Online TPP Program

#Id: 9613

#XL - T Zoology

In the absence of insulin, the extracellular domain adopts a symmetric inverted U-shaped conformation. 

TLS Online TPP Program

#Id: 9614

#XL - T Zoology

Upon insulin binding, the extracellular domain is converted into a T-shaped conformation that brings the transmembrane domains together.

TLS Online TPP Program

#Id: 9615

#XL - T Zoology

Four related EGF receptors participate in signaling by the many members of EGF family :

In the mouse - Erb-B1, 2, 3, and 4

In humans - HER 1, 2, 3, and 4