lecture 12

Question 1

some errors in transcription

Answer 1

Regulatory sequences:

promoters- at beginning of gene

enchancers- errors a 10,000s base pairs away

LCR- errors hundreds of thousands of base pairs way

Methylation- DNA gets binded and transcription is stopped

Demethylation- DNA gets unbinded and transcription is started in spots you don’t want to happen

these errors only effect that one gene that is being expresses

Question 2

regulatory sequence errors

Answer 2

affect mainly that one gene that is being transcribed

Question 3

transcription factor errors

Answer 3

affect all genes regulated by that factor

Question 4

transcription factor errors are either ___ or ____

Answer 4

inactivation

gain of function errors (translocations, overexpression)

Question 5

common translocation errors

Answer 5

give rise to blood cancers
B and T cell errors

translocation can lead to new protein being made
or important protein being cut and not made correctly

Question 6

RNA processing splicing defects

Answer 6

-splice junctions
GU AG

-branch sites
lariat structure

-splicing proteins

B thalassemia

Question 7

Polyadenylation errors

Answer 7

poly A signal sequence
AAUAAA changed and then protein cuts at next one-
Bglobin errors

poly A proteins

Question 8

errors in RNA stability mutants

Answer 8

AUUUA sequences

-RNA that you want to break down lose their AUUUA and become stable and cause issues in the cell

Question 9

translation errors

Answer 9

-errors could result in 20 x change in how RNA is turned into proteins

• initiation consensus
• initiation factors (viral)
• translation factors and neoplastic transformation

Question 10

factor VIII point mutants

Answer 10

CpG

gets methylated

C changes to T

this is okayish unless CpG is followed by A

TGA is a stop codon

this can lead to hemophilia

Question 11

trinucleotide repeat diseases

Answer 11

Fragile X syndrome
CGG in front of protein coding region

apinobulbar muscylar atrophy
CAG inside coding

myotonic dystrophy
CTG at end of coding

huntington’s disease
CAG inside coding

Question 12

is trinucleotide repeat disease is outside protein coding region it affects

Answer 12

stability of RNA or the RNA translatability

Question 13

is trinucleotide repeat disease is inside the protein coding region it affects

Answer 13

change how protein is folded

Question 14

genetic tests are limited by

Answer 14

1. risk vs certainty
2. lineage information
3. chromosomal crossovers
4. sample contamination
5. human error

Question 15

tests to diagnosis

Answer 15

• southern Blot
• western Blot ElIZA
• polymerase Chain reactions
• DNA sequencing
• microarrary analysis
• deep sequencing
• single nucleotide polymorphisms (SNPs)

Question 16

PCR advantages

Answer 16

great for detecting rare DNA (virus)

• amplify DNA and obtain sequence
• can detect small insertions and deletions
• can detect rare mutant cells within sample of many normal cells (leukemia)
• can use to monitor therapy
• short DNA
• need to know DNA sequences to make primers
• less ideal for screening large parts of genome

Question 17

RNA Sequencing

Answer 17

RNA seq or DNA seq

gives the entire repertoire of transcripts

• can determine numbers of each transcript
• can identify all splice variants
• can detect allele-specific expression
• an important step in personalized medicine

in fast and accurate
has superseded microarrays

Question 18

*** you have normal and disease tissue samples from our patient. you would like to compare the gene expression profile in these samples. What diagnostic method would you use?

Answer 18

microarray assay

Question 19

*** a mouse hepatitis virus outbreak has closed your lab. The outbreak appears to be contained. What test would you use to detect trace levels of virus in your mouse?

Answer 19

PCR

Question 20

errors in these are the most common cause of diseases

Answer 20

enzymes

Question 21

during development in utero errors in these are a big cause of disease

Answer 21

transcription factors