A screen has identified a mutant cell that is unable to migrate along the basal lamina. Sequence analysis reveals the presence o
f two mutations in the transmembrane domain of integrin alpha 6, that normally localizes to the plasma membrane, and which plays a critical role in cell adhesion. The mutations are as follows: Leu --> Asp and Trp --> Lys. Which of the following statements best describes a reason for why the mutant cell does not migrate in a fibronectin-coated dish? The cell does not migrate because..... a. the cell cannot form desmosomes b. the cell cannot form an adhesion belt c.the cell cannot form the branched actin cytoskelton at the leading edge d. the cell cannot adhere to the fibronectin that has been used to coat the dish e. The cell is unable to link its actin to the ECM via cadherins
Answer: The correct option is D (the cell cannot adhere to the fibronectin that has been used to coat the dish).
Explanation:
Mutation is an alteration in DNA sequences which occurs due to insertion, deletion or base substitution. This in turn leads to different malfunctions of the cell. Sequence analyses are methods that are used to determine the amino acid sequence of parts of a protein. For example, when a DNA is subjected to sequence analysis,it helps to identify differences and variations such as mutation.
The mutant cell identified in the screen revealed the presence of two mutations in the transmembrane that plays a critical role in cell adhesion. The cell does not migrate because the cell cannot adhere to the fibronectin that has been used to coat the dish, thus, the adhesion properties is lost due to mutation in the transmembrane. I hope this helps, thanks.
In primary succession, newly exposed or newly formed rock is colonized by living things for the first time. In secondary succession, an area that was previously occupied by living things is disturbed, then re-colonized following the disturbance.
Answer:Primary succession occurs on land that is new and has never had a flora and fauna example: glacier retreats, lava flows. Secondary succession occurs on land that has been cleared example: by fire, of flora and fauna, but which still has viable seeds and spores in the soil.
This type of Endoplasmic Reticulum has ribosomes around its outer membranes hence is a major organelle in the processing of cell proteins. When polypeptide chains are formed in the ribosomes, they enter the lumen of the RER where they are folded properly using chaperones and post-translational modification carried out on them.
