Login

Calculating % recombination and Mapping distanceModerator: BioTeam
3 posts • Page 1 of 1
Calculating % recombination and Mapping distanceHey,
Im confused on how to caluclate the percent recombination and the the mapping distznce in map units. Heres my problem: Consider a cross in Neurospora involving two allelles at the same locus,C and c. The following tetrad patterns were observed CCcc 55 ccCC 40 CcCc 7 cCcC 3 CccC 4 cCCc 5 What is the percent recombination and the approximate distance between the genetic locus and the centromere is? I can't calcualte my percent recombination because im unsure jof the significant difference. But I clacuated my mapping distance by: Getting the sum of all my numbers which is 114,then I added the 4 smaller numbers and I got 19. Now for my calcualteions 19/114=0.166 then divide by 2 since its two genotpyes that are CC and cc. which equals 0.083,then I multiply by 100 which give me 8.33 mapp units. But How do I find my percent recombination from my data? Are there seperate equations for percent recombination and the mapping distance? Thank you ttyl
You calculated everything correctly. 8.33 m.u. is also = to 8.33 % which is recombination frequency (1% RF= 1 m.u.).
Your reasoning is not correct though (unless I misunderstood you). You said “19/114=0.166 then divide by 2 since its two genotypes that are CC and cc.” 0.166… or 16.6% is frequency of crossover during meiosis, but only ½ of the product is recombinant. That is why you have to divide by 2; RF = 1/2 of the frequency of crossover during meiosis in this case.
3 posts • Page 1 of 1
Who is onlineUsers browsing this forum: No registered users and 3 guests 
© BiologyOnline.org. All Rights Reserved. Register  Login  About Us  Contact Us  Link to Us  Disclaimer & Privacy  Powered by CASPION