Question

Questions 25 refers to the following scenario. You want to investigate the genes that underlie muscle physiology in order to treat devastating muscular diseases and to increase the steak production at the slaughterhouse. In the laboratory you randomly mutate the genome of mice with ENU and discover two mutants with defects in muscle formation. You sequence the genome of these mutants and find point mutations in the myostatin gene. Homozygous mice with mutation 1 show increased muscle mass – mighty mouse. However, homozygous mice with mutation 2 show decreased muscle mass. What would be a reasonable conclusion regarding the role of this gene – barbell in muscle development?

What would be a reasonable conclusion regarding the role of this gene – barbell in muscle development? (Hint - First identify the most probable physical and genetic classification of each mutation)

A

The normal function of Barbell is to increase muscle development?

B

The normal function of Barbell is to inhibit muscle development?

C

The normal function of Barbell does not involve muscle development?

D

One cannot not make an educated conclusion, because you don’t know the phenotype of a KO?

Answer 1

The normal function of Barbell is to increase muscle development.

This is beacuse in mutant 1 there is synonymous mutation I.e changes in codon does not affect the amino acid sequence so , here mutant1 is a wild type analogue ,it's phenotype is as same as wild type.

In mutant 2 there is non-synomymous mutation thereby affecting the amino acid sequence and ultimately the protein function.