Background
The meaning of the acronym MTJ.
What is myotendinous junctions?
Follow up: Why do we perform FRAP on MTJs? What was their reasoning in the paper?
The device that measures the mechanical force on the larvae.
What is force transducer?
The contraction magnitude and frequency ____ for para mutated larvae.
What is decreased?
What is Bidirectional signalling?
The reason Brkd allele mutation was used instead of Swing mutation allele in assessing effects of hyper-contraction.
What is the Swg allele induced extreme seizure-like phenotypes, complicating FRAP analysis.
The meaning of the acronym IAC.
What is intracellular adhesion complex?
___ instar larvae were chosen for Brkd, and ___ instar larvae were chosen for para mutants.
What are First and Third?
Follow up: What was the purpose of using different larvae?
True or False: At 37˚C, the average displacement of muscle ends at MTJs during muscle contractions increased in the Brkd genotype compared to wild-type.
What is False?
The force of the muscles increased, but the displacement of muscle ends did not!!
When examining Para point mutations, the mutants' mobile fractions ___ after heat shock compared to the wild type.
What is increased?
The descriptions of PINCH and Tiggrin.
What is a widely expressed focal adhesion protein, crucial for cell modulation and signal transduction, and a novel Drosophila ECM protein?
This is the dimerization order of integrins and the role integrins play in force transduction.
What is heterodimer and a linkage between the ECM and actin microfilaments through IAC?
The variables used for B-integrin at the membrane and B-integrin in the endocytic vesicles in the developed mathematical model.
What are Im and Iv?
The effect of Brkd on mobile fraction of beta-integrin, Tensin, and ILK.
What is a decrease in mobile fraction?
Follow up... Why?
When the Brkd mutant was tested against control in the first instar, the mobile fraction of integrin, tensin, and ILK all ____ after heat shock.
What is decreased?
The name of the graph generated from recording variations in motion/pressure of muscles.
What is a kymograph?
The three temperature sensitive mutants impacting muscle contraction, and their effect on cell physiology.
Note: all must induce different effects on physiology.
What are Breakdance/Brk (induce hyper-contraction), Paralytic/para (suppress muscle contraction), and Shibere/shi (inhibits endocytosis)?
Swing (induce hyper contraction) also acceptable instead of Brkd.
Note: Must get shi or 1/2 points will be rewarded.
They tested controls in severe conditions to determine that this factor would not harm the MTJs.
What is photobleaching?
The difference between control first and third instar larvae with respect to changes at 25˚C compared to 37˚C.
What is increase in endocytotic and exocytotic rate constants?
This type of B-integrin turnover declined sharply at each successive stage of development.
What is wild type?
The purpose of the four point mutants in beta-integrin investigated in the paper.
What is to identify key beta-integrin molecular mechanisms underlying changes in adhesion dynamics in response to force?
S196>F, YY>FF (or Y831>F/Y843>F), N828>A, and N840>A mutations
Three proteins present in the intracellular adhesion complex (also known as the focal adhesion complex).
What are Talin, ILK, focal adhesion kinase (FAK), Paxillin, Vinculin, kindlins, and alpha-actinin?
Note: 2/3 gives 1/2 points.
Integrin recycling and intracellular-protein-binding.
What are the two models for fitting FRAP recovery curves?
The primary difference between Brkd and para induction with respect to contraction frequency and sarcomere displacement.
What is para decreases both contraction frequency and sarcomere displacement, where Brkd only significantly affects contraction frequency by increasing it?
Note: 1/2 marks if any portion incorrect
True or False: More force increases turnover, and less force decreases turnover.
What is false?
Describe the method for building up bootstrap distributions of parameter estimates (estimating bootstrap confidence intervals).
Simpler question: Describe the MTJ mechanosensing model under increased tension and reduced tension.
What is (i) using regression to estimate best fit parameters, (ii) compute the residuals, (iii) resample the residuals with replacement, (iv) adding resampled residuals to best-fit recovery curve to generate bootstrap dataset, (v) estimating new best-fit parameters, and (vi) repeating resampling and fitting procedure to build up bootstrap distributions for each parameter estimate? [Must get >4/6 to obtain points]
What is increased tension lower the proportion of integrins turning over and stabilizes adhesions, while integrin signalling in reduced tension prevents increased turnover in adhesions?