{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Lecture 7 Bio325 Fall 07

Lecture 7 Bio325 Fall 07 - Fig 5.10 Mapping the relative...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
1 Mapping the relative distances between 3 loci in a single cross: Fig. 5.10 total the recombinants for each pair of loci individually use these 3 map distances to create a map of all 3 loci Fig. 5.11 vg b pr + and vg + b + pr progeny must come from double crossovers in a 3 pt. cross, double-crossover progeny always constitute the smallest group of recombinants
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2 Double crossovers cause the recombination frequency between loci to be underestimated: vg-b distance is underestimated because double-crossovers look like parentals Correct the underestimation by identifying the double-crossover progeny and counting them twice in the calculation of map distance this yields the correct vg-b distance of 18.7 m.u. The map estimates for shorter distances are thus more likely to be correct than the map estimates for longer distances The expected # of double-crossovers can be estimated by multiplying the frequencies of the individual crossovers, since each is an independent event example: vg pr b 12.3 6.5 0.123 x 0.065 = 0.008 (or 0.8 m.u.)
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}