Biology

Genomic DNA from a family where sickle-cell disease is known to be hereditary, is digested with the restriction enzyme MstII and run in a Southern Blot. The blot is hybridised with two different 0.6 kb probes, both probes (indicated in red in the diagram below) are specific for the β-globin gene (indicated as grey arrow on the diagram below). The normal wild-type βA allele contains an MstII restriction site indicated with the asterisk (*) in the diagram below; in the mutated sickle-cell βS allele this restriction site has been lost. What size bands would you expect to see on the Southern blots using probe 1 and probe 2 for an individual with sickle cell disease (have 2 βS alleles)?     Probe 1 Probe 2 (a) 0.6kb 0.6kb and 1.2kb (b) 0.6kb and 1.8kb 0.6kb, 1.2kb and 1.8kb (c) 1.2kb 0.6kb (d) 1.8kb 1.8kb   a. (a)   b. (b)   c. (c)   d. (d)

Kpn I and Acc 65I are restriction enzymes that identify and cleave the same 6-bp sequence. The sticky end created by Kpn I cleavage, on the other hand, cannot be directly ligated to the sticky end formed by Acc 65I cleavage. Please explain why.

A 19 year old female patient is diagnosed with chronic myelogenous leukemia. Karyotype analysis shows that the leukemic cells of this patient are heterozygous for a reciprocal translocation involving chromosomes 9 and 22. However, none of the normal, nonleukemic cells of this patient contain the translocation.  a) Describe a molecular test to determine if chemotherapy given to the patient described would be completely succesful. (That is, devise a method to make sure that the patient's blood would be free of leukemic cells.) Be as specific as possible.