Lecture 17

Question 1

Forward Genetics vs Reverse Genetic?

Answer 1

Forward: Go from phenotype to genotype
Reverse: Go from genotype to phenotype

Question 2

Easiest to grow vs Hardest to grow order them?

Answer 2

Yeast
C.elegans
D.melanogaster
Danio Rerio
Mouse
(opposite is most like humans)

Question 3

What organisms are least like humans?

Answer 3

Those that are the most divervent

Question 4

Yeast

Answer 4

-Eukaryotic, unicellular
-Diploid/Haploid
-2-3 hour generation time
-Asexual or sexual reproduction
-Can be frozen

Question 5

Generation Time?

Answer 5

-Time needed to produce an offspring that is also able to reproduce

Question 6

Yeast life cycle?

Answer 6

1. Can exist as haploid (a strain or alpha strain). Can reproduce asymmetrically to produce identical daughter
2. Diploid yeast can reproduce asexually to make diploid yeast
3. Diploid can undergo sporulation in stress which produces haploid

Question 7

C.elegans

Answer 7

-invertebrate
-Multicellular
-3 days generation time
-translucent
-Can be frozen

Question 8

Invariant development of C.elegans

Answer 8

Each c.elegan has 1090 cells that are each developped in the same exact order inn every worm

Question 9

Sexes of C.elegans?

Answer 9

Hermaphrodite(XX): can produce asexually (XX) can spontaneously produce males (XO)
Males(XO): Produce sexually with XX

Question 10

C.elegan life cycle?

Answer 10

1. Eggs laid
2. Embryonic development (14hrs)
3. Larvae produced
4. Larvae grow over a day

Question 11

Dauer State of C.elegans?

Answer 11

When stressed C.elegans go into frozen hybridization state where they don’t eat or do anything

Question 12

D.melanogaster

Answer 12

-Invertebrates
-Multicellular
-Have body axis(anterior/posterior)
-CNS, digestive system

Question 13

How many genes ddo fruit flies share with humans?

Answer 13

75%

Question 14

Danio Rerio

Answer 14

-vertebrate
-Generation time 2-3 months
-Translucent embryos + larva

Question 15

What are dani rero used for?

Answer 15

-Have gills so it is very easy to treat them with drugs and then do toxicity screens on them

Question 16

Mouse

Answer 16

-Vertbrate
-3 month generation time

Question 17

Emergin model organisms?

Answer 17

-Do things humans can’t do
Ex. Axolotyl and Planaria

Question 18

Axolotyl

Answer 18

-Can cut off a limb and it will regenerate a new limb

Question 19

Planaria

Answer 19

-Can cut into three sections and each section will grow an entirely new worm

Question 20

Randy Scheckman

Answer 20

Discovered COP II vesicles ( coat and all the proteins)

Question 21

After the pulse where are the proteins?

Answer 21

ER

Question 22

After a 3 min pulse + 10 min chase where are the proteins?

Answer 22

Golgi

Question 23

After a 3 min pulse + 40 mins where are the proteins?

Answer 23

Secretory vesicles

Question 24

T/F: If you mutate genes involved in secretion the organism is most likely going to die?

Answer 24

True

Question 25

Temperature sensitive mutations?

Answer 25

Affect the genes at one temperature but not the other

Question 26

Permissive temp vs restrictive?

Answer 26

Permissive : organism is wild type Restrictive: Mutant phenotype

Question 27

How many total sec mutants are there?

Answer 27

50

Question 28

How do sec mutants differ?

Answer 28

-Some make the ER swollen -Some made vesicles trapped between ER/Golgi -Some made the golgi swollen -Some had a bunch of vesicles in PM

Question 29

What type of mutant was Sec1?

Answer 29

bunch of secretory vesicles inside the plasma membrane but they could not fuse with the plasma membrane and release their contents

Question 30

How to test if two yeast have mutations in the same genes?

Answer 30

Complementation

Question 31

If sec 13 and sec23 are mutations on the same gene....

Answer 31

They will not complement and will produce mutant phenotype

Question 32

If sec13 and sec23 are not mutations on the same gene...

Answer 32

They will complement and produce a wild type phenotype

Question 33

Two human genes homologous to yeast Sec23?

Answer 33

Sec23a and Sec23b

Question 34

Cranio-lenticulo sutural dysplasia

Answer 34

Amino acid change in Sec23A from phenylalanine to leucine -Vesicles are unable to bind their coat proteins