Transcription Part 2

DNA methylation inheritance

Heritable

Epigenome

Total collection of DNA structural alterations

Somatic cell nuclear transfer

Cloning procedure

Ideal demethylation

All genes get demethylated in the egg

Incomplete demethylation

Actual situation in cloning

Donor epigenetic state

Affects methylation of cloned DNA

Parent-of-origin specific

Imprinting

Faster repair

Transcribed DNA strands compared to non-transcribed strands

Cockayne syndrome

Defective transcription-coupled DNA repair

Reporter assay

Insert promoter/enhancer in front of reporter (e.g., GFP)

GFP measurement

Indicates transcription level

Specific mRNA

Quantitated to measure transcription

Northern blot

Determines how long mRNA is and how much is present

Probe

Small, single-stranded, labeled with radioactivity

Microarray analysis

Measures multiple mRNAs

Conditions

Used to determine effect on global gene expression

Complementary DNA

Produced when reverse transcriptase reads mRNA

Species-specific DNA sequences

Spotted individually on microarray

Hemoglobin (Hg) mRNA level

0

Actin (An) mRNA level

Low

Keratin (Kn) mRNA level

Medium

ATP synthase (AS) mRNA level

High

Fragile X syndrome

CGG repeat expansion, methylation shuts down FMR1