Cell Polarity And Migration

Front 1

at what stage does dramatic reorganization of MT cytoskeleton occur in Drosophila oocyte?

Back 1

stage 7-8 (mid oogenesis)

Front 2

How is egg chamber organized prior to reversal?

Back 2

1) oocyte posterior of egg chamber
2) localized components posterior to oocyte
3) MT array remains (-) end in oocyte and (+) end in nurse cells

Front 3

In reversal of polarization, where are (-) and (+) ends of MT situated?

Back 3

(-) end in anterior end
(+) end in posterior end

Front 4

e.g. of plus end motors?

Back 4

Kinesin

Front 5

e.g. of minus end motors?

Back 5

Nod and Dynein

Front 6

what is the role of mRNA localization?

Back 6

prevents mRNA transcripts from going to incorrect regions of oocyte

Front 7

What does mislocalization cause?

Back 7

e.g. Oskar and nanos going to anterior end causes anterior ends to adopt posterior fate

Front 8

How is mRNA transport possible?

Back 8

mRNA binding proteins recognize 3' untranslated regions of transported mRNA that associate with molecular motors and mediate mRNA transport

Front 9

When does egg in C.elegans become asymmetrical?

Back 9

sperm entry point

Front 10

What event does sperm entry in C.elegans activate?

Back 10

MT nucleation

Front 11

In 16 cell cyst how are all cells connected?

Back 11

cytoplasmic bridges

Front 12

What keeps fusomes together?

Back 12

alpha and beta spectrin
adducin-like protein

Front 13

which cell becomes the oocyte?

Back 13

cell with most fusome

Front 14

where does the fusome plug form?

Back 14

in the ring canal

Front 15

Where is PAR-1 found in Drosophila?

Back 15

restricted to the futuer oocyte in a MT-dependent manner

Front 16

What is PAR-1 role in Drosophila?

Back 16

1) localization of MTOC
2) regulation of MT density in anterior vs posterior

Front 17

What is PAR-1 role in C.elegans?

Back 17

1) cortical localization in Post and protein degradation in Ant
2) germline determinants (P-granules) to posterior and progressively to germline progenitor cell (P4)

Front 18

What is PAR-1?

Back 18

a protein kinase

Front 19

apical protein complex in drosophila neuroblast is present when?

Back 19

present in all ectodermal cells, delaminating neuroblast, from interphase until late anaphase; from there its disappeared until next interphase

Front 20

What is the apical protein complex?

Back 20

Baz/PAR6/aPKC

Front 21

explain Miranda's activity?

Back 21

Initially in apical region, but moves to basal in prophase

Front 22

explain Numb's activity?

Back 22

It is uniform during interphase, but moves to basal in prophase

Front 23

what is the relationship b/w neuroblast and epidermoblast division?

Back 23

neuroblasts divide perpendicularly wrt to epidermoblast division; epidermoblast division is symmetrical

Front 24

at which end are there more cortical force generators in C.elegans?

Back 24

posterior end

Front 25

In c.elegans cell divison, in which cell does the centrosome-nucleus complex rotate? Which cell divides in a plane different from perviously?

Back 25

1) P1 cell
2) AB cell

Front 26

what are scribble, discs-large, and lethal giant larvae also known as?

Back 26

neoplastic tumor suppressing genes

Front 27

What controls cell movement?

Back 27

cytoskeleton
ECM
selective cell adhesion

Front 28

Where does a neural growth cone go towards, and what does it avoid?

Back 28

chemoattractant; chemorepellant

Front 29

what are the receptors for guidance molecules for neural growth cones?

Back 29

EphA and B, Robo, Plexin, Fra (Frazzled)/DCC/UNC40, UNC5

Front 30

in which case will neural growth cones cross the midline?

Back 30

when Comm is expressed, downregulating Robo

Front 31

what ligand acts both as a chemorepellant and attractant

Back 31

Netrin

Front 32

What is the relationship b/w adhesion and locomotion?

Back 32

Inverse, more adhesion means slower movement and vice versa

Front 33

what are the Rho GTPase family members? What role do they play?

Back 33

1)Rho, Rac, Cdc42
2)trigger actin polymerization

Front 34

What does Cdc42 do?

Back 34

promotes formation of actin bundles to form filopodia

Front 35

What does Rac do?

Back 35

promotes polymerization at cell periphery leading to formation of lamellipodia

Front 36

What does Rho do?

Back 36

bundlign AF and myosin II filaments into stree fibres
clustering integrins and associated proteins to form focal contacts

Front 37

Which end do Rho GTPase family members work on?

Back 37

Cdc42 and Rac promote protrusion, Rho induces retraction

Front 38

How is Rho protein activation/deactivation mediated?

Back 38

GDP/GTP exchange and GTP hydrolysis