Rollin Hotchkiss and Julius Marmur studied transformation in the bacterium Streptococcus pneumoniae (R. D. Hotchkiss and J. Marmur. 1954. Proceedings of the National Academy of Sciences of the United States of America 40:55-60). They examined four mutations in this bacterium: penicillin resistance (P), streptomycin resistance (S), sulfanilamide resistance (F), and the ability to use mannitol (M). They extracted DNA from strains of bacteria with different combinations of different mutations and used this DNA to transform wild-type bacterial cells (P* St F* M*). The results from one of their transformation experiments are shown here. Recipient Percentage of all cells Donor Transformants DNA DNA MSF M* s* F* M* SF* 4.0 M* s* F 4.0 M S* F* 2.6 MSF* 0.41 M* SF 0.22 M S* F 0.0058 MSF 0.0071

You have identified a SNP marker that in one largefamily shows no recombination with the locus causinga rare hereditary autosomal dominant disease.Furthermore, you discover that all afflicted individuals in the family have a G base at this SNP on theirmutant chromosomes, while all wild-type chromosomes have a T base at this SNP. You would like tothink that you have discovered the disease locus andthe causative mutation but realize you need to consider other possibilities.a. What is another possible interpretation of the results?b. How would you go about obtaining additional genetic information that could support or eliminateyour hypothesis that the base-pair difference is responsible for the disease?

Four E. coli strains of genotype a+ b- are labeled 1, 2, 3, and 4. Four strains of genotype a- b+ are labeled 5, 6, 7, and 8. The two genotypes are mixed in all possible combinations and (after incubation) are plated to determine the frequency of a+ b+ recombinants. The following results are obtained, where M = many recombinants, L = low numbers of recombinants, and 0 = no recombinants:On the basis of these results, assign a sex type (either Hfr, F+, or F-) to each strain.

DNA from a strain of Bacillus subtilis with the genotype trp" tyr* was used to transform a recipient strain with the genotype trp tyr". The following numbers of transformed cells were recovered: Number of transformed Genotype cells trp* tyr 154 trp tyr* trp" tyr* 312 354 What do these results suggest about the linkage of the trp and tyr genes?

1.) If Ethidium bromide was not added to a gel, what would happen? 2. How can you tell if an individual is heterozygous for the D1S80 marker?

Determine the coefficient of coincidence and the interference

In a three-point mapping experiment for the genes a-w-ec, the following percentages of events are observed: NCO events: 57%; SCO events between a and w: 18%; SCO events between w and ec: 22%; DCO events: 2% Assuming that w is in the middle, what is the map distance between w and ec? What is the map distance between a and w? Draw the map.

Identity gene 1 (bl, pr, vg) Identity gene 2 ( bl, pr, vg) Identity gene 3 ( bl,pr, vg) How many map units separate genes 1 and 2 ( Distance 1)? How many map units separate genes 2 and 3 ( distances 2) ?

Four Hfr strains are derived from an F+ strain of E. Coli to serve as donors for an interrupted-mating experiment. Use the time-table and partial map of the F+ strain (shown below) to determine the genes’ respective positions. Keep in mind that the map distances are NOT proportional, only the FIRST 5 markers are indicated per strain, and the entry times, recorded in minutes, are in parentheses. Transferred genes represent wild-type alleles. Based on the data, which gene can be located at position 5 on the map?

Cystic fibrosis (CF) is a genetic disorder affecting a number of organs, including the lung airways, pancreas, and sweat glands. Mutations in both copies of the CFTR gene causes cystic fibrosis. Imagine that you have sweat gland samples from several Cystic Fibrosis patients (A-C) with unknown mutations in CFTR. You also have normal (+) sweat gland sample to use as a positive control. А В С А В С Choose which mutation would explain the RNA and protein results in A, B, & C: 1. Promoter/Regulatory mutation 2. Silent mutation 3. Missense mutation 4. Deletion mutation 5. Splice site mutation 6. Nonsense mutation RNA gel Protein gel