L6 - Intro to Drosophila

Question 1

Advantages of mouse

Answer 1

Good genetics

Well established

Question 2

Advantages of chick

Answer 2

Accessible embryos

Low cost

Question 3

Advantages of zebrafish

Answer 3

Accessible embryos

Reasonable cost

Question 4

Advantages of drosophila

Answer 4

Accessible embryos and adult stages
Very low cost
Excellent genetics
Not ethical conserns

Question 5

Disadvantages of mouse

Answer 5

Expensive 
Slow (long generation time)
Home office/ethical restrictions

Question 6

Disadvatages of chick

Answer 6

No genetics

Home office/ethical restrictions

Question 7

Disadvantages of zebrafish

Answer 7

Genetics are problematic

Home office/ehtical considerations

Question 8

Disadvabtages of drosophila

Answer 8

Not a vert

Kept as live stocks

Question 9

At 25 deg how long is drosophila life cycle

Answer 9

10 days

Question 10

At 18 deg how long is drosophila lifecycle

Answer 10

21 days

Question 11

What occurs in first 3 hours of drosophila lifecycle

Answer 11

Go from fertilised egg to a segemented embryo with 3 germ layers

Question 12

How many larval stages

Answer 12

3

Question 13

What do the larvae do

Answer 13

Essentailly eating machines to build up fat (energy used during metamorphisis)

Question 14

Why do larval have 3 stages

Answer 14

Get too big for their skin so the only option is the shead it

Question 15

Describe what happens in the pupal stages

Answer 15

Crawls up the side of the vial and the skin hardens

Question 16

Describe what happens during metamorphisis

Answer 16

Larval tissue dissovlves and adult body shell forms

Fat accumulated during instar stages used to provide energy for this process

Question 17

Lifespan of drosophila

Answer 17

Average around 60 days

Question 18

What did morgan discover in 1910

Answer 18

The white eyed fly

Question 19

What was constructed in 1913 by Stutevant

Answer 19

Constructed the first genetic map with genes being arrnaged in a linear order

Question 20

In 1927 what did muller show

Answer 20

That X rays causes mutations and chromosomal mutations

Question 21

What occured in 1979/1980 performed by volhar and wischaus

Answer 21

Saturation mutagenesis to identify genes involved in patterning and development

Question 22

Example of technqiue for trangenics

Answer 22

P-element transformation

Question 23

What occured in March 2000

Answer 23

The drosophila geneome was sequenced

Question 24

How many Chr in drosophila

How many Chr arms

Answer 24

5 Chr

7 arms

Question 25

What are the 7 drosophila Chr arms

Answer 25

``` X 2L 2R 3L 3R 4 Y ```

Question 26

How many bases on the 7 chromsome arms

Answer 26

137.6 Mbps

Question 27

The remaining gaps of around 1.5 mbps are found where ...

Answer 27

In heterochromatin regions

Question 28

Around how many genes in drosophila

Answer 28

17600

Question 29

Ptp61F is a

Answer 29

tyrosine phsophatase

Question 30

When allignement of ptp61F is performed what aras appear to be conserved

Answer 30

Exons | Regulatory sequences

Question 31

1 male and 1 female drosophila can give rise to

Answer 31

Upwards of 200 offspring

Question 32

What does drosophila courtship include

Answer 32

``` Orientation Tapping Wing vibration Licking Attempted copulation ```

Question 33

What different sensory modalities does drosophila courtship include

Answer 33

Audiotion - olfaction - taste - vision

Question 34

How was it shown drosophila courtship was genetic

Answer 34

Two dros grown in isolation and in dark | When reintroduced they still perform the courtships acts

Question 35

What is found at the very tip of the testes

Answer 35

Hub cells

Question 36

What is maintained immediatly adjacent to the hub cells

Answer 36

A stem cell population

Question 37

What occurs when stem cell in the testes divides

Answer 37

One closest to the hub cell maintains stem cell fate Other cell divides and can give rise to upward of 60 spermatids

Question 38

What do hub cells secrete What is this involved in

Answer 38

Upaired (ligand) Invovled in the JAK/STAT pathway

Question 39

What is attached to each ovary

Answer 39

Strings of ovarioles

Question 40

Where is sperm stored in the feamle

Answer 40

Seminal receptacel

Question 41

Where is the egg laid

Answer 41

Drilled into the foot where it is laid

Question 42

To form the oocyte how many divisions may occur

Answer 42

4 incomplete cytoblast mitotic divisions

Question 43

What occurss in the nurse cells

Answer 43

Endo-reduplication - many copies of the genome contained here

Question 44

What do the nurse cells produce

Answer 44

Maternal factors for the devleoping oocyte

Question 45

Give as example of a maternal contribution

Answer 45

Oskar mRNA

Question 46

Describe the process of relocalising maternal contributions form the nurse cells to the oocyte

Answer 46

Cytoplasmic dumping occurs via ring canals

Question 47

What can occur after cytoplasmic dumping via ring canals

Answer 47

Some of the genes and gene products can be actively localised to regions of the egg

Question 48

What must occur in order for activation of the egg

Answer 48

Fusion of the male and female pronuclei

Question 49

Describe polytene chromsomes

Answer 49

Giant chromsomes which occur when the DNA is duplicated by not separated

Question 50

What occurs when a polytene chromosome is stained for pol2

Answer 50

Bands show little gene activiy Interbands show an active gene Puffs show and extremly active gene

Question 51

Describe the localisation of bicoid and oskar mRNA

Answer 51

Bicoid - anterior of the cell | Oskar - posterior

Question 52

How is cytoplasmic localisation of maternal contributions achieved

Answer 52

Through transport by the cytoskeleton | (Microtubules, plus and minus ended motors, glue then anchors them into postion

Question 53

What is the chorion

Answer 53

The egg cell - secreted by follicle cells

Question 54

What is the vitelline membrane

Answer 54

A hydrophobic coating which prevents the egg from drying out

Question 55

Egg development occurs via a series of Of which there are ___ stages

Answer 55

Nuclear division 14

Question 56

During early development in drosophila there is no

Answer 56

External gene expression

Question 57

During drosophila early development where do most of the nuclei end up

Answer 57

End up on the outside of the egg

Question 58

What occurs in drosophila after the 14th division

Answer 58

Membranes go up from the outside and each nucelus pinches off into its own cell

Question 59

Describe the drosophila larva

Answer 59

Segmented into a denticle belt

Question 60

What occurs in a Stat92e (-/-)

Answer 60

There are gaps where some of the segemetns should be