Exploring flow transport in egg cells

A new and unique transport mechanism for developing egg cells in fruit flies has been discovered by scientists.

The microtubule creates a current that brings nutrition and molecules to the developing egg cell. The senior author of the study, Vladimir Gelfand, said that this flow transport had previously only been detected in plants.

This is a completely new mechanism of biological motion in animals, according to Gelfand.

Stem cells can be found very early in an organisms lifespan. During the oocyte's development,nurse cells give it materials to build the structures necessary for development.

Early in this process, the protein dynein directionally transports other proteins and mRNA by walking along microtubule tracks. This is an example of how to maintain the cell fate, according to the research associate in the Gelfand laboratory and lead author of the study.

Lu said that the oocyte needs to maintain its status as an oocyte.

The investigators observed the transport method changing midway through oocyte development. The same motor, dynein, attached to the cortex of nurse cells, pushes the microtubules through small canals towards the oocyte. As if riding a tube down a river, the flow upon which molecule are transported is generated by this.

It is the same mechanism asselective transport, but it is inverted. Gelfand said that instead of components moving on microtubules, they move to the oocyte.

In the study, investigators placed neutral particles inside the nurse cells and watched as they rode the current towards the oocyte. The neutral particles would stay put if the old method of directed transport was still being used.

The investigators took motor proteins from moss and attached them to nurse cells. The growth of the egg cell is normal because of the artificial motor.

Gelfand said that it doesn't matter what is moving if the flow is in the right direction.

It is difficult to verify this mechanism in mammals because they are more complex and thicker. Gelfand's laboratory will explore when transport switches can be switched fromselective to non-selective, as there may be a biological triggering that flips the switch.

More information: Wen Lu et al, A novel mechanism of bulk cytoplasmic transport by cortical dynein in Drosophila ovary, eLife (2022). DOI: 10.7554/eLife.75538 Journal information: eLife Citation: Exploring flow transport in egg cells (2022, March 14) retrieved 14 March 2022 from https://phys.org/news/2022-03-exploring-egg-cells.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.