User:Ilya/Yeast/Sexual dimorphism

Cell type specification

Three specific transcription factors are encoded at the MAT locus:

• α1
• α2
• a1

One general transcription factor, MADS type: MCM1

• exibits different activity in ha and halpha cells
• activator or repressor

PRE: pheromone response element

Mating type conversion:

• happens in haploid only
• during late G1 phase
• in one of mitotic products: mother cell

Asymmetric mitotic division: mother and daughter cells are different Example from other species: stem cells produce specialized siblings

Ash1 localized to daughter cells prevents Swi5 TF from activating expression of HO endonuclease -> restrict switching of mating types to mother cells

Why have asymmetric types: a & alpha?

Signal transduction pathway appears identical in a and α types.