1. In the background section the authors wrote “We hypothesized that the content
ID: 3518988 • Letter: 1
Question
1. In the background section the authors wrote “We hypothesized that the content of hetero-multimeric CaMKII controls the mitochondrial and contractile phenotype of skeletal muscle and that this would take place in both slow-twitch m. soleus (SOL) and fast-twitch m. gastrocnemius (GM).” Write this hypothesis as a null hypothesis. (1 point)
2. In the “CaMKII overexpression and phosphorylation in skeletal muscle” section of the results section the authors wrote “?/?-CaMKII-transfection increased protein levels of ?- and ?-CaMKII isoforms at 50 and 60 kDa, respectively, compared to control-transfected SOL muscle (Figure 1A).” Which type of macromolecule was used for the transfection? (1 point)
3. How do you know that your answer to question 2 is correct? (1 point)
4. In general, what happened/happens between transfection and increased protein levels? (1 point)
5. In the “?- and ?-CaMKII co-overexpression shifts gene expression towards a fast phenotype with enhanced calcium handling” section of the results section the authors wrote “A larger fraction of CaMKII-transfected fibers expressed MHCII than non-transfected fibers.” Why was less MHCII expressed in non-transfected fibers? (1 point)
6. In the discussion section the authors wrote “In contrast to our hypothesis, we did not observe altered expression of mitochondrial protein(s) in ?/? CaMKII-transfected muscle fibers of rats housed under normal cage activity.” Was their hypothesis a null hypothesis or an alternate/alternative hypothesis? (1 point)
7. How do you know that your answer to question 6 is correct? (1 point)
8. In the “Technical considerations” section of the discussion section the authors wrote “This raises the hypothesis that an increase in sarcoplasmic calcium levels in injured muscle fibers enhances expression of the fast fiber type program, through a CaMKII-dependent mechanism.” Is this a null hypothesis or an alternate/alternative hypothesis? (1 point)
9. How do you know that your answer to question 8 is correct? (1 point)
10 In the “Technical considerations” section of the discussion section the authors wrote “Whether CaMKIV would have a similar function in skeletal muscle compared to CaMKII is questionable, since the two proteins have different substrate specificity and intracellular localization.” Based on this, what kind of protein is CaMKIV? (1 point)
11. Based on this article alone, how do you know that your answer to question 10 is correct? (1 point)
*** REFERENCE***
https://bmcphysiol.biomedcentral.com/articles/10.1186/s12899-014-0007-z
Explanation / Answer
1. Null Hypothesis:
"Content of Hetero-multimeric CaMKII does not control Mitochondrial and contractile phenotype of skeletal miscle and this will nt take plane in slow twitch M. soleus (SOL) and fast twitch Gastrocnemius (GM)"
2. Transfection:
"A process of deliberately introducing purified nucleic acid into eukaryotic cells."
In above experiment, alpha/beta CaMKII plasmid was used for transfection and led to wxpression of elevated CaMKII in fibres of SOL & GM Muscles.
6. In above study, null hypothesis was true because they did not observe altered expression of mitochondrial proteins in alpha and beta CaMKII tramsfected muscle fibres of Rat.
10. BAsed on ave study, it can be concluded that CaMKIV is a Recombinant Human Protein.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.