Dictyostelium cells shown to lay 'breadcrumb trail' as first step in multicellular formation

Dec 01, 2008

When starved of their food source and then presented with a chemoattractant signal like cAMP, individual Dictyostelium cells acquire a polarized morphology and aggregate to form a migrating stream. This is the first step in a developmental program that culminates in the formation of a multicellular organism. Kriebel et al. show how this streaming response is coordinated at a single-cell level in the December 1, 2008 issue of the Journal of Cell Biology.

Besides acquiring a polarized morphology and beginning to chemotax, Dictyostelium cells respond to cAMP signals by making their own cAMP, thereby recruiting yet more cells to join the parade. The team previously discovered that ACA—the enzyme that makes cAMP—is highly enriched at the back of migrating cells.

They thus proposed that the attractant is released mainly from the rear of cells, which prompts fellow cells to align and generate head-to-tail streaming structures. Kriebel et al. now show that ACA is packaged into intracellular vesicles that cluster at the rear of cells in a process that is dependent on actin and microtubule networks. They also show that de novo protein synthesis is required to maintain the asymmetrical distribution of the ACA vesicles.

Interestingly, the ACA-containing vesicles themselves, not just their contents, are deposited behind the Dictyostelium cells like a breadcrumb trail as the cells crawl along. As cAMP is a small and diffusible molecule, perhaps the vesicles serve to package the chemoattractant so that it doesn't immediately diffuse away, says author Carole Parent.

Citation: Kriebel, P.W., et al. 2008. J. Cell Biol. doi:10.1083/jcb.200808105.
www.jcb.org

Source: Rockefeller University

Explore further: Watch for pet poisons around your home, and form a plan for emergency response

add to favorites email to friend print save as pdf

Related Stories

US clears $2.3 bln Lenovo deal for IBM unit

1 hour ago

IBM said Friday that US authorities had cleared a $2.3 billion deal allowing China-based Lenovo to take over its server unit after a national security review.

Hitchhiking robot charms its way across Canada

1 hour ago

He has dipped his boots in Lake Superior, crashed a wedding and attended an Aboriginal powwow. A talking, bucket-bodied robot has enthralled Canadians since it departed from Halifax last month on a hitchhiking ...

Attack Ebola on a nanoscale

4 hours ago

(Phys.org) —The Ebola virus outbreak in West Africa has claimed more than 900 lives since February and has infected thousands more. Countries such as Nigeria and Liberia have declared health emergencies, ...

Phone snooping via gyroscope to be detailed at Usenix

5 hours ago

Put aside fears of phone microphones and cameras doing eavesdropping mischief for a moment, because there is another sensor that has been flagged. Researchers from Stanford and defense research group at Rafael ...

Recommended for you

Of bees, mites, and viruses

6 hours ago

Honeybee colonies are dying at alarming rates worldwide. A variety of factors have been proposed to explain their decline, but the exact cause—and how bees can be saved—remains unclear. An article published on August ...

User comments : 0