Lecture 16 - Embryo Developement

Front 1

Three strategies for initiating different gene expression during development

Back 1

mRNA localization
cell to cell contact
signaling through the diffusion of a secreted signaling molecule

Front 2

mRNA localization is achieved through an adapter protein binds to the _____ of RNA and binds to the ________ to be transported.

Back 2

3' UTR, cytoskeletion

Front 3

The adaptor protein attached to the cytoskeletin through what protein?

What direction does it travel on the polarized actin filament?

Back 3

myosin, towards the positive end

Front 4

There are three different mechanisms of signal transduction activated by a __________ binding to a cell ________ receptor.

Back 4

ligand, surface

Front 5

What are these three different mechanisms?

a. ________ cascade that leads to ________ of a DNA-binding protein in the nucleus

b. Activation of a latent _______ DNA-binding protein to enter the nucleus.

c. When ligand bind to receptor, the ____________ is cleaved and a part enters the nucleus to activate a _____________.

Back 5

Kinase, phosphorylation

cytoplasmic

receptor, DNA binding protein

Front 6

The concentration of an __________ signal regulates gene expression.

Back 6

extracellular

Front 7

The _________ diffuses through the extracellular matrix with ________ cells binding more of the __________.

Back 7

ligand, nearby, ligand

Front 8

The more receptors that are activated by the diffused ligands, the ________ the signal that is transduced to stimulate the ___________ of different genes.

Back 8

stronger, transcription

Front 9

The mating type switchin in mother yeast cells is from ______ to _____.

This switching is possible because the _______ gene is turned _________ via ________ localization.

Back 9

a, alpha

HO, on, mRNA

Front 10

The _______ repressor mRNA is localized to the __________ cell.

This is done by the _____ and ______ adaptor proteins.

This localization prevent ____ expression and mating type switching in __________ cells.

Back 10

Ash1, daughter

She2, She3

HO, daughter

Front 11

On the Ash1 mRNA, the ______ protein attaches to the 3' UTR.

Then the ______ protein attached to _________ V.

______ and ______ attaches to each other and ________ drives the movement down the polarized actin filament.

Back 11

She2

She3, myosin

She2, She3, myosin

Front 12

Localization of the _______ mRNA drives ______ muscle developement in the sea squirt.

Back 12

Macho-1, tail

Front 13

At fertilization, the egg is induced to undergo a highly asymmetric division to produce a small ______ body (top). At this time, the Macho-1 mRNA becomes localized to ______ (vegetal) regions.

Back 13

polar, bottom

Front 14

the Macho-1 mRNA undergoes a __________ wave of localization. This occurs during the second highly asymmetric meiotic division of the egg.

Back 14

second

Front 15

nuclear divisions in drosophilia embryogenesis

__________ nuclei in one cell after _______ rounds of nuclear division

Back 15

6000, 14

Front 16

Developement of germ cell -

_______ migrate to the edges of the cell. They become ________ cells.

The pole cells become __________ cells.

Back 16

Nuclei, somatic

germ

Front 17

Spatzle toll and dorsal gradient:

The _____ receptor is uniformly distributed throughout the _______ membrane of the precellular embryo. The Spatzle signaling molecule is distributed in a gradient in the ________ region.

Back 17

tool, plasma, venteral

Front 18

Activation of the ______ receptor leads to the activation of the ______ kinase in the cytoplasm. Pelle either directly or indirectly phosphorylates the ________ protein, which binds and inhibits the ________protein. Phosphorylation of_____________ causes its degra-dation, so that ________ is released from the
cytoplasm into nuclei.

Back 18

toll, pelle, cactus, dorsal, cactus, dorsal

Front 19

Different affinity Dorsal binding sites allows the expression of the ________, __________, and ______ genes in a unique pattern in the ventral nuclei.

Back 19

twist, rhomboid, sog

Front 20

The sog genes have 4 __________ dorsal binding site.

the rhomboid gene hace 1 __________ affinity dorsal binding site

the twist genes have 2 __________ affinity dorsal binding sites.

Back 20

optimal
high
low

Front 21

The presence of the ________ repressor in the ____________ mesoderm prevents ____________ and ________ expression in this region.

therefore only _________ is expressed.

Back 21

Snail , ventral

rhomboid, sog

twist

Front 22

In the unfertilized egg, what mRNA is localized to the anterior pole and which to the anterior pole?

Back 22

Bicoid to the anterior

Oskar to the posterior

Front 23

The Oskar protein helps coordinate the assembly of the ____________(2) in the posterior cytoplasm. Nuclei that enter this region bud off the posterior end of the embryo and form the _______ cells.

Back 23

polar granules,

pole

During the formation of the Drosophila egg, polarized microtubules are formed that extend from the oocyte nucleus and grow toward the posterior plasm. The oskar mRNA binds adaptor proteins that interact with the microtubules and thereby transport the RNA to the posterior plasm.

Front 24

Placement of the Bicoid 3’-UTR on
the Oskar mRNA causes ______ cells
to grow in place of a _______.

Back 24

germ, head

Front 25

The Bicoid protein gradient induces
expression of the _________ protein.

Back 25

hunchback

Front 26

A second (___________) promoter allows
Hunchback mRNA to be present
throughout the cell.

Back 26

maternal

Front 27

However, translation of the Hunchback mRNA is blocked at the opposite
(posterior) end of the cell by the ______ protein. it is secreted by the ____ cells (blue�

Back 27

nanos, pole

Front 28

The Hunchback protein represses expression of the _____, _________,
and ________ genes to different extents leading to a _________ expression
of the _____ gene.

Back 28

kruppel, knirps, giant

striped

Eve

Front 29

High levels of Hunchback are required for the re- pression of ________, but low levels are sufficient to repress ________.

Back 29

kruppel, giant

Front 30

he Kru ̈ppel and giant 5' regulatory DNAs contain different numbers of Hunchback repressor sites.

There are ______ sites in Kru ̈ppel, but ______ sites in giant.


The in- creased number of Hunchback sites in the giant enhancer may be responsible for its re- pression by _____ levels of the Hunchback gradi- ent.

Back 30

three, seven

low

Front 31

What other protein probably
represses Kruppel?

Back 31

knirps

Front 32

The EVE gene uses what to control gene expression?

Back 32

many enhancer regions

Front 33

What kind of pattern does it have?

Back 33

t striped pattern

Front 34

Stripes #__ and #__ are located very upstream from the coding region.

Down stream from these stripes is stripe #__, this strip is still however upstream from the coding region.

Down stream from the coding region is stripe #__ and #__.

Down stream from these two stripes are #__ and #__.

Back 34

3,7

2

4,6

1,5

Front 35

Eve stripe 2 expression is inhibited by __________ and ________.

It is activated by ______ and ____________.

Back 35

kruppel, giant

bicoid, hunchback

Front 36

Differential regulation of the stripe 3 and stripe 4 enhancers by opposing gradients of the __________ and __________ repressors.

Back 36

hunchback, knirps

Front 37

The two stripes are positioned in different regions of the embryo. The eve stripe 3 enhancer is repressed by high levels of the ___________ gradient but low levels of the _________ gradient.

Back 37

hunchback, knirps

Front 38

Conversely, the stripe 4 enhancer is repressed by ____ levels of the Hunchback gradient but ______ levels of Knirps.

Back 38

low, high

Front 39

What kind of genes control the expression of body parts?

Back 39

homeotic

Front 40

What does a mutation in the Antennepedia (Antp) gene cause?

Back 40

Leg growth where the antenna normally develop

Front 41

A mutation in the Ubx gene (ultrabithorax) causes a duplication of what?

Back 41

Duplication of the mesothorax where the metathorax normally develops.

Front 42

Duplication of the mesothorax results in what?

Back 42

2 sets of wings and no halteres (used for balance)

Front 43

The Ubx normally functions to repress _____ in the _______thorax. Mutations in Ubx prevents this repression.

Back 43

Antp, meta

Front 44

MISEXPRESSION of Ubx in the mesothorax results in what?

What is this mutant called?

Back 44

Loss of wings and 2 sets of halteres

Cbx

Front 45

In branchiopods, Ubx is expressed in segments T1-T8.

In isopods, changes in Ubx expression (aka loss in ___ segment) leads to expression of _________ in ___.

What develops instead of legs?

Back 45

T1, Scr, T1

maxilliped feeding appendages

Front 46

Ubx represses _____-specific genes (maxillipeds) in crustaceans.

In insects Ubx, it represses _____ development as well.

Back 46

head, leg

Front 47

Misexpression of the fruitfly Ubx protein in leg areas ____________ leg
development in fruitflies, but expression of the shrimp Ubx
protein in this region does not ____________leg development.

Back 47

suppresses, suppress

Front 48

In the sCRUSTACEAN shrimp Ubx protein, what allows for the developement of many sets of legs?

It is located in the ________ terminal and blocks the activity of the ________ terminal repression domain.

Back 48

anti-repression motif

carboxyl (C), amino (N)

Front 49

The presence of a second set of wings in (lepidopteran) butterflies
is a result of evolved mutations in ___binding sites to prevent
____ binding and repressing wing formation.

Back 49

UBX

UBX

so Ubx supresses wing formation