Related Experiment Video

Updated: Jul 7, 2026

Live Imaging of Drosophila Larval Neuroblasts
09:50

Live Imaging of Drosophila Larval Neuroblasts

Published on: July 7, 2014

Akt regulates centrosome migration and spindle orientation in the early Drosophila melanogaster embryo

Graham J Buttrick1, Luke M A Beaumont, Jessica Leitch

  • 1Department of Zoology, University of Oxford, Oxford OX1 3PS, England, UK.

The Journal of Cell Biology
|February 13, 2008
PubMed

Insights

The protein kinase Akt is crucial for proper cell division in fruit fly embryos. Reduced Akt levels disrupt mitotic spindle positioning, leading to nuclear abnormalities and cell shape defects.

Area of Science:

  • Cell Biology
  • Developmental Biology
  • Molecular Biology

Background:

  • Correct positioning and morphology of the mitotic spindle are essential for accurate cell division.
  • Microtubule (MT)-cortical actin interactions regulate mitotic spindle organization.
  • Disruptions in these processes can lead to developmental abnormalities.

Purpose of the Study:

  • To investigate the role of the protein kinase Akt in regulating mitotic spindle positioning and orientation in the early Drosophila melanogaster embryo.
  • To identify downstream targets and interacting partners of Akt involved in this process.

Main Methods:

  • Used Drosophila melanogaster early embryos with reduced levels of the protein kinase Akt.
  • Assessed centrosome migration, mitotic spindle morphology, and nuclear positioning.
  • Investigated the phosphorylation status of Zw3 and the cortical localization of APC2 and EB1.
  • Examined mitotic spindle orientation in postcellularized embryos.

Main Results:

  • Reduced Akt levels caused incomplete centrosome migration, bent mitotic spindles, and nuclear loss.
  • Akt is enriched at the embryonic cortex and is required for Zw3 phosphorylation.
  • Akt regulates the cortical localization of APC2 and the MT + Tip protein EB1.
  • Akt reduction led to APC2 mislocalization and mitotic spindle misorientation.

Conclusions:

  • Akt plays a critical role in stabilizing microtubule-cortex interactions during early embryonic development.
  • Akt regulates a complex involving Zw3, Armadillo, APC2, and EB1.
  • This Akt-mediated complex is essential for proper centrosome separation and mitotic spindle orientation.

More Related Videos

Imaging Centrosomes in Fly Testes09:41

Imaging Centrosomes in Fly Testes

Published on: September 20, 2013

Live-Cell Imaging of Drosophila melanogaster Third Instar Larval Brains07:06

Live-Cell Imaging of Drosophila melanogaster Third Instar Larval Brains

Published on: June 23, 2023

Related Concept Videos

Spindle Assembly02:50

Spindle Assembly

Spindle assembly occurs through three, often coexisting, pathways – the centrosome-mediated pathway, the chromatin-mediated pathway, and the microtubule-mediated pathway – collectively contributing to form a robust spindle apparatus.
In most cells, centrosomes are the primary microtubule nucleation centers. In the centrosome-mediated pathway, the G2-prophase transition triggers centrosome maturation and increased microtubule nucleation. Progressive nucleation results in a microtubule array...
Centrosome Duplication02:25

Centrosome Duplication

The primary microtubule organizing center (MTOC) in animal cells is the centrosome. A centrosome has two cylindrical centrioles at its core. Each centriole consists of nine sets of three microtubules held together by proteins. The centrioles are positioned at right angles to each other and surrounded by a shapeless protein cloud called the pericentriolar matrix, or pericentriolar material (PCM).
To ensure that each daughter cell receives a centrosome after cell division, centrosome duplication...
The Mitotic Spindle02:27

The Mitotic Spindle

The mitotic spindle—or spindle apparatus—is a eukaryotic, cytoskeletal structure made up of long protein fibers called microtubules. Formed during cell division, the spindle separates sister chromatids and moves them to opposite ends of a parental cell, where the now individual chromosomes are distributed to two daughter cell nuclei.
The bipolar configuration of the mitotic spindle facilitates chromosomal segregation, preparing the cell for division. One mechanism that ensures bipolar mitotic...
Centrioles and Centrosomes01:13

Centrioles and Centrosomes

Most animal cells comprise a pair of centrioles together called a centrosome. The cell duplicates its centrosome and contains two centrosomes side-by-side, which begin to move apart during the prophase. As the centrosomes migrate to two different sides of the cell, microtubules start extending from each centrosome toward the other end. The mitotic spindle is composed of the centrosomes and their emerging microtubules.
Near the end of the prophase, also called late prophase or "prometaphase,"...
Determining the Plane of Cell Division02:13

Determining the Plane of Cell Division

Positioning the cell division plane is a critical step during development and cell differentiation, particularly during mitosis when the plane is essential for determining the size of the two daughter cells. The cell division plane is perpendicular to the plane of chromosome segregation, but different types of organisms have different cell division mechanisms to suit their morphology and function. 
Animal cells
In animal cells, the cleavage furrow forms along the plane of cell division starting...
Forces Acting on Chromosomes02:11

Forces Acting on Chromosomes

During mitosis, chromosome movements occur through the interplay of multiple piconewton level forces. In prometaphase, these forces help in chromosome assembly or congression at the equatorial plane, eventually leading to their alignment at the metaphase plate. The forces acting on the chromosomes are space and time-dependent; therefore, they vary with the position of the chromosomes as the cell progresses through mitosis. 
Microtubules and motor proteins exert two types of forces on...