GENE20001 Lecture Notes - Lecture 3: Wild Type, Chromosome
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Most sensible gene order therefore:
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BUT 13.2 + 6.4 = 19.6 ≠18.5. discrepancy because double recombinants were
inappropriately treated as parentals. To account for them:
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Genetics Page 5
Document Summary
But 13. 2 + 6. 4 = 19. 6 18. 5. discrepancy because double recombinants were inappropriately treated as parentals. Note we multiply double recombinants by 2 since they recombine twice. Ratio of observed double crossovers to the expected number. Positive interference: observed drs are less than expected - crossover in one region inhibits crossover in the adjacent region. Negative value for interference: observed drs are more than the expected drs - crossover in one region promotes crossover in the adjacent region. Mutations e, cu and ro are all linked on chromosome iii. Homozygous e; cu; ro female mated with homozygous wild-type male and phenotypically wild-type female progeny are mated with homozygous e; cu; ro males. 311 e; cu e; ro cu; ro e cu ro. Order of the 3 mutations on chromosome iii is: cu; e; ro. In drosophila, dp and sp are on second chromosome, 94 map units apart. True breeding sp females are mated with true breeding dp males.
