lec 6 Flashcards
What are the three main types of CRISPR/Cas9 genome editing approaches?
Wild-type Cas9 – introduces double-strand breaks (nonhomologous end joining or homology-directed repair).
Cas9 nickase – introduces single-stranded nicks.
Nuclease-deficient Cas9 – binds but cannot cut DNA
What are examples of social behaviors tested in mice?
Huddling, social grooming, social approach, ultrasonic vocalization, nest building, pup care, and aggression.
How is social approach behavior tested in mice?
Using a three-chamber social approach test to see if the mouse prefers interacting with a social target.
How is aggression tested in mice?
A single male mouse is housed alone for a month, and then an intruder is introduced to measure aggression.
What test is used to assess visual and spatial memory in mice?
The Morris water maze (MWM).
What is passive avoidance learning?
A test where mice learn to avoid a dark chamber associated with an unpleasant stimulus like a shock.
How is associative learning tested in mice?
Through taste aversion tests using substances like lithium chloride paired with a specific flavor.
What is the difference between conditioned and unconditioned fear responses?
Conditioned fear – Fear triggered by a previous experience.
Unconditioned fear – Innate fear of a threat (e.g., open spaces).
How is anxiety measured in the elevated plus maze test?
Mice with higher anxiety avoid the open arms of the maze.
What is the forced swim test used for?
To assess depression-like behavior; SSRIs reduce immobility time.
What does the sensorimotor gating test measure?
The ability to filter out repeated sensory stimuli (measured by pre-pulse inhibition)
Sensorimotor gating is a neurological ‘gating’ process that
prevents repeated sensory inputs from generating unnecessary motor outputs ! regulation is disrupted in Schizophrenia and Huntington disease → antipsychotics increase pre pulse inhibition of startle response
What is conditioned place preference?
When a mouse spends more time in a place associated with a drug reward.
How is drug self-administration measured in mice?
Mice press a lever or poke their nose into a hole to receive a drug reward
What does the rotarod test measure?
Motor coordination and balance based on how long the mouse stays on a rotating rod.
How is visual acuity tested in mice?
Using the visual cliff test to see if the mouse stops at the edge of a surface.
How is pain sensitivity measured in mice?
By placing the mouse on a hot surface and measuring the time until it responds (e.g., jumping or licking a paw).
How is auditory sensitivity tested?
Using an acoustic startle chamber to measure the mouse’s response to loud sounds.
How does the JAX mouse phenome database assist researchers?
It provides data on behavioral traits in mice to support comparative and genetic research.
How does RNA in situ hybridization work?
A complementary RNA probe (riboprobe) binds to the target mRNA.
The probe is labeled using fluorescent dye or a colorimetric tag.
What is the Allen Brain Atlas?
A digital atlas showing gene expression patterns in mice and humans.
How can BACs be used in genetic studies?
Identify BAC clone containing the target gene.
Insert transgene into BAC.
Perform pronuclear microinjection to express gene in vivo.
How does the Cre-LoxP system work?
Promoter C – Contains LoxP sites recognized by Cre enzyme, which cuts at these sites.
Promoter A – Contains Cre enzyme under a cell-specific promoter.
Cross two mice (one with C, one with A) to selectively activate or delete genes.
