Flashcards in Case unit 4 Deck (16):
what types of disease models are there
difference between cell dish and body
2D vs 3D
cell vs cell contacts
pO2 - normix conditons
benefits of using mice
share a genome
inbred mouse strains
several inbred mouse strains exist which mimic aspects of human disease
- NOD mouse (non obese diabetic)
- Lep ob/ob
do not necessarily reflect cause of human disease
make target genes knock in/out
informed by genetic research
how to make a mouse
breed mice to get germline mutations
modify embronic stem cell
inject into mother
breed chimeric offspring
screen for germlin transmission
knock outs/ knock ins
often performed to determine the physiological function of a gene
can introduce specific mutations
limitations of mouse models
timing - day/night cycle effect response
gender - men increase mice stress
cage - not challenged by normal environment
mice have different physiolgy to humans
Think of a process e.g. cell division
Pick a model organism
Break every gene individually (chemical mutagen)
Does the process still work?
If not – identify the broken gene!
advantages of screening
CRISPR-Cas9 is a unique technology that enables geneticists and medical researchers to edit parts of the genome by removing, adding or altering sections of the DNA sequence.
What are the to key molecules in CRIPSR
an enzyme called Cas9.
a piece of RNA called guide RNA (gRNA).
what does cas9 do
acts as a pair of ‘molecular scissors’ that can cut the two strands of DNA at a specific location in the genome so that bits of DNA can then be added or removed.
what does guide RNA do
consists of a small piece of pre-designed RNA sequence (about 20 bases long) located within a longer RNA scaffold. The scaffold part binds to DNA and the pre-designed sequence ‘guides’ Cas9 to the right part of the genome. This makes sure that the Cas9 enzyme cuts at the right point in the genome.