3: L13

Question 1

What does a transcription factor do

Answer 1

• Transcriptional Proteins bring enhance/proximal/promotor regions together so that other TF can interact with them = bring complexes together= activate gene expression (can make more transcription factor which can regulate genes)

Question 2

What is the interaction between Maternal vs Zygotic determinants

Answer 2

o Zygotic begin to supersede maternal to drive production/secretion of proteins
o Different timelines for different species

Question 3

What does the NANON, BICOID, HUNCHBACK interaction do in general

Answer 3

Patterning of A-P axis during cleavage event

Question 4

Describe NANON, BICOID, HUNCHBACK

Answer 4

• Hunchback begins evenly distributed posterially/ anteriorly
o But at point in time= nanos suppresses it in anterior region= sets up gradient

• (anterior posterior axis, subtle control mechanisms)
o In Anterior: Bicoid activates zygotic hunchback (even distribution) + produces hunchback protein
 Bicoid also inhibits cordal mRNA > caudal protein process
o In Posterior: nanos protein suppresses hunchback protein production

Question 5

what are gap genes

Answer 5

• Gap genes - mutation causes loss of contiguous body segments,
o (gap in normal body plan)

Question 6

what is Krupple

Answer 6

o inhibited by high levels of hunchback, giant, and tailless (establishes anterior boundary of Krüppel expression) & knirps
o activated by low levels of bicoid and hunchback, (establishes posterior boundary of Krüppel expression.

Question 7

what are hox/hom genes

Answer 7

• Specify order of type of structures along a line (“memory” for A-P order already established by earlier developmental specific genes)
• Crucial to initiate and maintain the body plan

Question 8

what is the Organizer Apical Ectodermal Ridge (AER):

Answer 8

• controls proximal to distal (ie shoulder to finger tip) growth & development

Question 9

What does low levels of • Fgf8-/- and Fgf4-/- result in

AER reigon

Answer 9

malformation of distal limb elements

Question 10

Besides Fgf8/4 name one other thing int he AER and what it does

Answer 10

• p63 also highly expressed in AER, and its deletion (p63-/-) impairs AER formation (Kawata et al_2017_Plos One)

Question 11

what does DNA methylation at gene promoters generally do

Answer 11

transcriptional repression

Question 12

What does DNMT do

Answer 12

(a) Local and cell-type-specific patterns of DNA methylation achieved through recruitment or repulsion of DNMTs to specific genomic sites
(b) DNA methylation-modifying enzymes DNMTs and TETs and their major accessory proteins, DNMT3L and UHRF1, display distinct activity patterns throughout early development