Review and quant genetics
The handout for quantitative genetics is online on the BIOL334 website:
http://www.zoology.ubc.ca:80/genetics/334-1998/web2004/quant.htm
Review session:
Thursday 2-4 pm, room 2321
Drop-in hours for people who can't make it to Thursday's (or who have last minute questions):
Friday, 8-ish-10am, room 2321
If you have any questions, leave a comment! (The function should be enabled now)
Cheers,
Pam
http://www.zoology.ubc.ca:80/genetics/334-1998/web2004/quant.htm
Review session:
Thursday 2-4 pm, room 2321
Drop-in hours for people who can't make it to Thursday's (or who have last minute questions):
Friday, 8-ish-10am, room 2321
If you have any questions, leave a comment! (The function should be enabled now)
Cheers,
Pam
posted by pam39 at 11:50 AM
8 Comments:
could we go over heterodimer suppression? (e.g. like how we know when heterodimer, linked or unlinked??)
Heterodimer suppressor:
let's say we are crossing to haploids, one is genotypically WT, the otehr is phenotypically WT but genotypically a double mutant. We would write it out as:
a+b+ X a-b-
where a may represent the ability to grow on a certain medium, and b, when mutated, "compensates for" (suppresses) the effect of a mutation in a.
The progeny of the cross will be:
a+b+ (WT)
a-b- (WT)
a-b+ (mutant)
a+b- (don't know)
If we are told that the only job of b is, when it is mutated, to suppress the phenotype of a-, then the last class will be phenotypically WT. Therefore, if a and b are unlinked, we should get a 3:1 ratio of WT: mutant. If a and b are linked, we will get a ratio that is anywhere between 1:0 (all WT) and 3:1 (WT:mutant), i.e. you get between 0% and 24.999999% mutants
It's non-heterodimer suppression.
If we are told that the products of gene a and b have to physically interact and work together as a heterodimer, then the last genotypic class (a+b-) will be phenotypically mutant. If a and b are unlinked we'll get a 1:1 ratio of WT: mutant; if a and b are linked we'll get anything between 0% and 49.99999% mutants.
It's heterodimer suppression.
So, if we don't know what type of suppression it is, but we know that the WT: mutant ratios in the progeny are 1:1, then we know that it must be heterodimer suppression (without linkage).
If we get between 25.01% and 49.9999% mutants (and the rest WT) it should be heterodimer suppression with linkage.
If we get 25% mutants, it may be heterodimer suppression with linkage or non-heterodimer suppression without linkage.
If we get under 25% mutants, then there is linkage, but we can't tell what type of suppression it is.
Warning: in many cases we are told in advance whether the genes we are working with are linked or not!
Hope this helps.
Pam, which section are you TA-ing for 335?
I was wondering if there will be 8am or 1:30pm tutorial available for BIOL 335 Summer?
I'll find out Monday what section of 335 I am assigned to.
There are currently no 8am or 1,30 pm sections available, but, depending on people's schedules and room availability, we may be able to turn a 2.30 one into a 1.30 or 8am one.
Cheers
Pam
Can you post the website for BIOL 335 here so that the people who aren't in your tutorial for 335, but was in your 334, can still access it?
Will do!
I'll turn this one into a 334/335 Summer blog (after I finish marking!).
Thanks Pam!
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