Yeast_genetics

Question 1

point of complementation analysis

Answer 1

to determine if mutant genes are in the same gene

Question 2

T/F. Complementation tests are tests of function

Answer 2

True

Question 3

what would you do to confirm a complementation test?

Answer 3

a linkage analysis - which is a test of position

Question 4

what is the tetrad segregation pattern called that results in two recombination events in which all 4 haploids are recombinants?

Answer 4

non-parental ditype

Question 5

what is the tetrad segregation pattern where all four haploids look like one of the original parental cells?

Answer 5

parental ditype

Question 6

tetratype

Answer 6

where segregation patterns produce two recombinant cells and two parentals (single recombination event)

Question 7

what is the tetrad segregation pattern for two linked genes?

Answer 7

PD > T > NPD, recombination unlikely as they are in the same or neighboring genes

Question 8

what is the tetrad segregation pattern for two unlinked genes?

Answer 8

PD = NPD > T, since recombination is likely, PD = NPD due to random segregation

Question 9

T/F. Linkage analysis relies on meiotic recombination

Answer 9

True

Question 10

what is a suppressor?

Answer 10

a compensatory mutation that restores WT phenotype

Question 11

why are suppressors handy?

Answer 11

to find genes in a pathway?

Question 12

intragenic suppressors?

Answer 12

suppressor in same gene - either true revertant, or second site mutation

Question 13

extragenic suppressor types (5)

Answer 13

interaction, bypass, epistatic, mass action, dosage, nonsense

Question 14

interaction suppressor

Answer 14

allele specific, does not rescue a null

Question 15

bypass suppressor

Answer 15

rescues a null, can also provide novel function to protein

Question 16

epistatic suppressor

Answer 16

type of bypass suppressor, rescues a null

Question 17

dosage suppressor

Answer 17

rare, restores balance in a system

Question 18

mass action suppressor

Answer 18

type of dosage, stabilizes mutant by interaction

Question 19

suppressors you might miss (4)

Answer 19

duplicated genes, essential genes, small genes, wrong assumption about phenotype

Question 20

synthetic lethality

Answer 20

where single mutants are viable, but double are lethal in the same cell

Question 21

SGA

Answer 21

synthetic genetic array, yeast specific - a method to screen genome wide for synthetic interactions that cause a diff growth pattern than expected

Question 22

how do you predict how large a mutant cross colony should be?

Answer 22

multiplicative model, if Ab = 0.5 and aB = 0.5, then the cross of the two should be 0.25

Question 23

can’t lose plasmid (yeast version)

Answer 23

deletion or mutation of interest covered by a URA3 plasmid, transform/mutagenize/plate on non-selective media, then when you replica plate onto 5-FOA the synthetic lethal colony will not grow on 5-FOA bc of the URA3 gene

Question 24

can’t lose plasmid (bacterial version)

Answer 24

deltion or mutant covered by unstable plasmid containing LacZ and ampR, perform transposon mediated mutagenesis, insertion of kanR, then screen library for kan, IPTG expressing LacZ, and pick colonies that turn blue with synthetic lethal plasmid

Question 25

three techniques for identifying suppressors

Answer 25

linkage analysis, whole genome sequencing, tn-seq

Question 26

high copy plasmid screen

Answer 26

where you transform mutant with high copy genomic library, each cell getting only one plasmid and each plasmid overexpressing one gene. plate so only suppressors will grow