Development

Question 1

Cloning success

Answer 1

The sooner you clone an animal the higher the success rate. Cells that are further along in differentiation are more difficult to reprogram

Question 2

What is the correct hypothesis for how genes differentiate?

Answer 2

Regulatory proteins -> cascade of regulatory interactions -> differentiation

Question 3

How did people figure out regulatory proteins?

Answer 3

Experiments with Drosophila in which certain genes were turned off, and the thorax went away. (Or other parts of the body or alternating segments)

Question 4

Segmentation Cascade

Answer 4

Asymmetries in the egg -> maternal gradients -> zygotic gap genes -> pair-rule genes -> segment-polarity genes -> hox genes

Question 5

HOX genes

Answer 5

Homeotic Complex genes. Hox proteins bind to DNA and regulate transcription… effectively deciding which parts of the body do what.

Question 6

Are HOX genes conserved across animal lineages?

Answer 6

Yes. Same eye hox gene for mice and flys

Question 7

Cytoplasmic segregation

Answer 7

Mechanism of differentiation. Daughter cells retain unequal amounts of regulatory proteins, and therefore express different things down the line.

Question 8

Model of differentiation from C. elegans

Answer 8

Primary inducer turns on one cell that is nearby a lot, other cells a little. Secondary induced leaves the most effected cell and turns the other cells on too. EGF and Notch receptors.

Question 9

Induction method of signaling.

Answer 9

Cell produces inducer, inducer spreads out and cells that are closer to it receive it and that turns on genes.

Question 10

Histone

Answer 10

The things that DNA is wrapped around to make chromatin