Section Nb

Section Homework Week 11: Curing Color Blindness?

a) How does gene therapy work?

Gene therapy aims to introduce specific genetic material into cells so that it can code for a functioning protein that may otherwise not already be produced in the cell because of abnormal genes. The genetic material is transferred into the cell by the use of a vector. Once the genes are incorporated into a vector the vector is then inserted into body tissue where it can be taken up by cells. Once the genetic material is taken up by cells, cells will then incorporate the new genetic material into their own genetic material and will start producing the desired protein(s).

b) What is ERG? What is an mfERG? What do the results in the figures show?

ERG is an electroretinogram which is a device that measures electrical responses of certain cells in the retina. Mf-ERG is a multifocal electroretinogram which was used to detect the spectral sensitivity shift in the monkeys after having been injected with the L-opsin and GFP coding viruses. The results in the figure show that at first, with only the 2 injections, in 1C at faint signs of GFP the L-opsin levels were not enough to produce suprathreshold mf-ERG signals. However it also showed that when the the when GFP signs were strong the red light of mf-ERG was seen at high amplitudes in the areas in which the injections where administered inside the eye. This however did not result in a homogeneous region. The trial with the three injections demonstrated the most mf-ERG response in region of the central retina which is the same area that allows for individuals to be able to tell between red and green well enough. Overall, these figures depict the results that gene therapy allowed for a change in the spectral sensitivity of some cones.

a) Why does colorblindness affect males more than females?

Since colorblindness is a sex-linked trait and since men have only one X-chromosome if their...