3HH3 module 5 lecture 15-post

3HH3 module 5 lecture 15-post - Asymmetric neuroblast...

Info iconThis preview shows pages 1–7. Sign up to view the full content.

View Full Document Right Arrow Icon
Asymmetric neuroblast divisions: Neuroblasts are precursors to differentiated neural cells (similar to stem cells) that repeatedly divide asymmetrically along their apical/basal axis. These unequal divisions produce: Larger apical daughters that remain as neuroblasts Smaller, committed basal daughter cells called ganglion mother cells (GMCs) that produce neurons
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Migration of neuroblast out of neuroectoderm Asymmetric neuroblast division Stem cell Committed Apical Basal
Background image of page 2
Par3 complex Bazooka = Par 3 Par6 aPKC Neuroblast: C.elegans zygote: And also, polarized epithelial cells in mammals
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Only when the microtubule and the Insc/Par pathways are simultaneously activated can mitotic spindle oriented along the apical-basal axis be coupled to the asymmetric localization of proteins All apical complex single mutants have the same phenotype: randomized spindle orientation and failure to reliably localize cell fate determinants to the basal cortex. This leads to an accumulation of undifferentiated neuroblast cells and a deficit of neuronal cells. Par complex localization is maintained by two proteins: Inscutable (Insc) and Partner of Inscutable (Pins).
Background image of page 4
Misplaced spindle at metaphase- anaphase prevents asymmetric division Mutations disrupting asymmetric divisions Required: Par3 complex (not shown) Inscutable Kinesin heavy chain (Khc) Spindle fails to re-orient Cortical polarity cues not properly localized
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
effect on apical/basal cortical polarity: 1) mushroom body defective (mud) 2) centrosomin (cnn) Role of spindle orientation: Cabernardand C. and C.Q. Doe. 2009. Apical/Basal Spindle Orientation Is Required for Neuroblast Homeostasis and Neuronal Differentiation in Drosophila Developmental Cell. 17(21):134-141. Both mutations
Background image of page 6
Image of page 7
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 04/13/2011 for the course BIOL 3HH3 taught by Professor Mccelland&dej during the Winter '11 term at McMaster University.

Page1 / 24

3HH3 module 5 lecture 15-post - Asymmetric neuroblast...

This preview shows document pages 1 - 7. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online