Vegetative cells begin sporulation when a key nutrient- carbon or nitrogen source becomes scarce.

TLS Online TPP Program

#Id: 6864

#Unit 3. Fundamental Processes

Su(var) mutations lie in genes whose products are needed for the formation of heterochromatin such as HDAC, HMT.

TLS Online TPP Program

#Id: 6865

#Unit 3. Fundamental Processes

E(var) mutations lie in genes whose products are needed to activate gene expression. They include members of the SWI/SNF complex

TLS Online TPP Program

#Id: 6866

#Unit 3. Fundamental Processes

HP1 (heterochromatin protein 1) is one of the most important Su(var) proteins. The HP1 chromodomain binds to histone H3 that is trimethylated at lysine 9 (H3K9me3).

TLS Online TPP Program

#Id: 6867

#Unit 3. Fundamental Processes

Mutation of a deacetylase that acts on H3K14Ac prevents the methylation at K9 because HDAC provide methylation sites for HMT.

TLS Online TPP Program

#Id: 6868

#Unit 3. Fundamental Processes

Methylation of H3K9 demarcates heterochromatin while H3K4 methylation demarcates euchromatin.

TLS Online TPP Program

#Id: 6869

#Unit 3. Fundamental Processes

Heterochromatin formation at telomeres and silent mating-type loci in yeast relies on an overlapping set of genes known as silent information regulators (SIR genes).