GN 301 Module 3: Regulation of Gene Expression and Epigenetics

histones

proteins complexed with DNA to form chromosomes

non-histine proteins

proteins complexed with chromatin to form coiled chromosome

Modifications of histones

affect gene expression

Histone acetylation

increases gene expression since the DNA and histones are less tightly joined

Function of RNA polymerase

 transcribes and produces the primary transcript

Function of transcription factors

bind to the promoter and then allow RNA polymerase to bind

Primary Transcript is processed to form mature mRNA

5’ cap is added, 3’PolyA Tail is added, introns are removed and exons are joined together

Role of Enhancers

A DNA sequence that increases the level of transcription of a gene that is located nearby on the same chromosome.

cDNA

DNA formed from active genes, produced by the enzyme reverse transcriptase.

DNA

________ is complexed with proteins called histones to form chromosomes.

Gene expression patterns

________ changed for twins about 7 % from what they used to be after one of them was in space for a year.

Epigenetics

Heritable changes in gene expression that occur without alterations in DNA sequences.

Some inherited epigenetic changes are

Methylation and Modifications of histones

Methylation epigenetic changes

Methylation of the base cytosine

Modifications of histones

such as acetylation of the amino acid lysine

chromosomes

complexed with DNA and histones

coiled chromosome

complexed with nonhistine proteins and chromatin

What produces the primary transcript?

RNA polymerase

What allows RNA polymerase to bind?

transcription factors

Introns and exons

introns are removed, exons are added to primary transcript