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Amoeba travel gets crazy without this gene

In the video above, amoebae with and without the PiaA gene crawl around in the presence of weak electric fields. (Credit: Wolfram Burner/Flickr)

Many living things can respond to electric fields, either by moving or using them to detect prey or enemies. Weak electric fields may be important to growth and development, and in wound-healing: it’s known that one of the signals that guides cells into a wound to repair it is a disturbance in the normal electric field between tissues.

This ability to move in response to an electric field is called galvanotaxis or electrotaxis.

Min Zhao, dermatology professor at the University of California, Davis, Peter Devroetes of Johns Hopkins University, and colleagues hope to unravel how these responses work by studying body cells and Dictyostelium discoideum, an amoeba that lives in soil.

Dictyostelium is unusual because it spends part of its life crawling around as a single-cell amoeba, but occasionally multiple amoebae will come together to form a fruiting body.

In Science Signaling, Zhao and colleagues report screening Dictyostelium for genes that affect electrotaxis. They used special barcoded microplates developed by Tingrui Pan, professor of biomedical engineering at UC Davis, to screen hundreds of amoeba strains.

The team identified a number of genes, including one called PiaA, which encodes a critical component of a pathway controlling motility. Other genes associated with electrotaxis in Dictyostelium were also linked to the same pathway.


Right now, no one knows how cells detect these very weak electric fields, Zhao says. The screening technique could be used to identify more genes linked to electrotaxis and help researchers piece together exactly how electrical signals are detected and turned into action.

Coauthors on the paper include biologists, engineers and mathematicians from UC Davis; Johns Hopkins University; State Key Laboratory of Trauma, Burns and Combined Injury, Third Military Medical University, Chongqing, China; and Yunnan Normal University, Kunming, China.

The National Science Foundation (US), the California Institute for Regenerative Medicine, National Institutes of Health, the National Science Foundation of China, and the Wellcome Trust supported the work.

Source: UC Davis