Lecture 10- Cell movements in animal development

Question 1

5 types of adhesion

Answer 1

tight junctions (actin filaments)
adherens junctions (linked to the cytoskeleton)
gap junctions (linked to microfilaments)
selectins (type of non-classical junction)
focal adhesion (linked to actin)

Question 2

how can adhesion be involved in cell sorting

Answer 2

differential adhesion hypothesis- differences in adhesion help set up and maintain tissue boundaries, patterns in adhesion leading to arrangement of tissues

Question 3

EMT

Answer 3

epithelial to mesenchymal transition- motile to static cells, determines if cells can move

Question 4

cellular changes associated with cell movement

Answer 4

actin polymerisation and depolymerisation at the leading edge
actomyosin formation, helping to generate force for migration as well as apical constriction

Question 5

what causes gastrulation

Answer 5

epithelial bending, force from apical side using ‘twist’ and ‘snail’ proteins

Question 6

how can the dimensions of cell sheets be changed

Answer 6

cytoskeletal reorganisation- can be triggered by Wnt signalling, creates cell sheets with different relative positions and therefore different overall lengths