Drosophila

Question 1

Stage in Drosophila where the nuclei have migrated to the edges, and membranes are forming, but are not complete

Answer 1

Syncytial Blastoderm

Question 2

Stage in Drosophila with complete cells outlining the inner yolk

Answer 2

Cellular Blastoderm

Question 3

What three components work to cellularize the blastoderm?

Answer 3

Microtubules stretch downwards from the nucleus, actin concentrates at the lowest in pockets, furrowing the membrane, and Cadherin junctions form down the crevice to maintain cellular adhesion.

Question 4

What external quality of drosophila allow researchers to see which segments might be missing?

Answer 4

Denticle bands

Question 5

What experiment proves that there are maternal polarity centers in the cytoplasm?

Answer 5

Draining anterior cytoplasm and adding posterior cytoplasm creates two posteriors.

Question 6

What do each mutant mRNAs [bicoid, nanos, torso] cause to be missing?

Answer 6

Bicoid - missing anterior. Nanos - missing posterior

Torso - missing terminal

Question 7

Where do bicoid and nano localize to, and with what carrier protein, and what motor?

Answer 7

Bicoid is carried by Exuperantia and dynein to the anterior. Nanos is carried by Oskar to the posterior.

Question 8

Effects of bicoid mRNA tightly localized to the anterior

Answer 8

Creates a gradient of bicoid protein towards the anterior. Prevents translation of caudal mRNA,and translates hunchback.

Question 9

Effects of nanos mRNA in tightly localized to the posterior

Answer 9

Creates a gradient of nanos protein towards the posterior. Prevents translation of hunchback, by binding of pumilio protein.

Question 10

Gap Genes list

Answer 10

Gt, Hb, Kr, Kni, Gt, Hb

Question 11

Hunchback: Maternal or zygotic?

Answer 11

Both

Question 12

Gap genes: maternal or zygotic?

Answer 12

zygotic

Question 13

Pair Rule Genes:

Answer 13

7 stripe pattern in the syncytial blastoderm

Question 14

Segment Polarity Genes

Answer 14

14 stripe pattern in the cellular blastoderm

Question 15

What is an example of a pair rule gene?

Answer 15

Fushi tarazu

Question 16

What is even skipped?

Answer 16

A gene that correlates with the overlap of gap proteins.

Question 17

How does even skipped determine which pair rule gene to express?

Answer 17

Even skipped has specific enhancer elements whose regulators are bicoid and other gap proteins.

Question 18

Example of segment polarity gene

Answer 18

Engrailed

Question 19

What separates the segment polarity genes?

Answer 19

An adjacent hedgehog wingless relationship.

Question 20

Positive feedback of wingless and hedgehog

Answer 20

Wingless protein is a Wnt that activates a frizzled, and through Disheveled, and Armadillo, activates transcription of engrailed and hedgehog. Hedgehog travels to a patched and smoothened receptor and through cubitus interruptus, it creates transcription of wingless.

Question 21

What is the start of gastrulation called for Drosophila?

Answer 21

The Ventral Furrow that involves apical constriction.

Question 22

What morphogenic movement creates the germ band in Drosophila?

Answer 22

Convergent Extension

Question 23

What are the proteins and alignments relative to the axis of extension?

Answer 23

The actin/myosin are orthogonal to the axis, and PAR3/Bazooka is parallel

Question 24

What shapes do cells create prior to extension?

Answer 24

Myosin contraction forms rosettes of cells

Question 25

Explain attennapedia

Answer 25

Where a drosophila has legs instead of antennae

Question 26

UltraBithorax Complex

Answer 26

two sets of wings

Question 27

In what order are homeotic genes anterior-posterior?

Answer 27

3’-5’

Question 28

Roughly equivalent Hox genes in mammals are called

Answer 28

paralogs

Question 29

Homeodomain

Answer 29

Similar domain in proteins between all metazoa

Question 30

Homeobox

Answer 30

Corresponding DNA to create the homeodomain throughout metazoan