6) You are trying to determine the relative order of three genes involved in lac

Question

6) You are trying to determine the relative order of three genes involved in lactose metabolism, lacA,IacZ and lacY. They all map by conjugation to 11 min on the E. coil chromosome. You do three experiments using trpE (12 mm) as an outside marker. In each experiment, you use a wild strain of E. coil as the donor, and a strain that is mutant for trpE and two of the lac genes as the recipient. You select for trpE recombinants and then score them for the lac phenotypes. The data for each cross is shown in the tables below. For each table show the order of the two lac genes relative to trpE. Finally, indicate the order of all three lac genes relative to trpE. (12 pts) .

Explanation / Answer

The order of the gene will be :- lac Z- lac Y- lac A.

The data of each experiment gives number of recombinant and parental type progenies. The first data will provide distance between Z and Y. Similarly second set will give distance between Z and A. Third set will give the diatance between A and Y.

Formula for calculating this: (no. of recombinant progeny/no. of total progenies) x 100= Distance in cm

Related Questions

Navigate

• Browse (All)
• Browse 6
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.