In: Biology
Researchers investigating cave fish found a new population in a previously undiscovered cave. These fish also lacked eyes, but different from the other populations, their eye development appeared to fail during lens induction. The researchers observed a failure to induce a lens placode. Their next goal was to determine the mechanism that caused loss of eyes in this population.
a) (2 points) The researchers hypothesized that a loss of function mutation in one or more of six possible genes was likely the cause. List the six most likely candidate genes.
b) (3 pts) How could the researchers determine if one of those six genes had a mutation.
c) (5 pts) Assume that the researchers found a mutation in one of those six genes. Describe an experiment the researchers could conduct using the surface fish as a model to determine if the identified mutation was sufficient to cause a failure of eye formation. List the possible results and highlight/underline the result that supports their hypothesis.
1.The below mentioned genes form the genetic basis for eye regression in cave fish.
Cryaa, pitx3,rx3, olfm2a, olfml2a, BCoR.
2. The researchers can do it by sequencing the corresponding gene . Let us suppose it to be Cryaa.
Procedure
Isolate DNA from the cave fish.
Design primers for Cryaa gene.
Amplify the gene by PCR.
Now do Sanger sequencing. For Sanger sequencing take 1micro litre of amplified gene, add only one primer , dNTPS,ddntps, polymerase enzyme, sequencing dye and buffer. Then do the sequencing PCR and proceed to Sanger sequencing. Now analyse the chromatogram of the gene obtained. Compare the sequence to Cryaa gene sequence of surface fish that don't has mutation.
3. For this the gene with mutation has to be incorporated to surface fish. The supposed mutation in Cryaa gene can be made in surface fish by using CRISPR technology.CRISPR helpsin editing gene sequence and thus Cryaa mutation can be made in surface fish in the early embryonic stage and further development of eyes in surface fish can be analysed.