A large-scale screen reveals genes that mediate electrotaxis in Dictyostelium discoideum

Abstract

Directional cell migration in an electric field, a phenomenon called galvanotaxis or electrotaxis, occurs in many types of cells, and may play an important role in wound healing and development. Small extracellular electric fields can guide the migration of amoeboid cells, and here, we established a large-scale screening approach to search for mutants with electrotaxis phenotypes from a collection of 563 Dictyostelium discoideum strains with morphological defects. We identified 28 strains that were defective in electrotaxis and 10 strains with a slightly higher directional response. Using plasmid rescue followed by gene disruption, we identified some of the mutated genes, including some previously implicated in chemotaxis. Amongst these we studied PiaA, which encodes a critical component of TORC2, a kinase protein complex that transduces changes in motility by activating the kinase PKB (also known as Akt). Furthermore, we found that electrotaxis was decreased in mutants lacking gefA, rasC, rip3, lst8 or pkbR1, genes that encode other components of the TORC2-PKB pathway. Thus, we have developed a high-throughput screening technique that will be a useful tool to elucidate the molecular mechanisms of electrotaxis.

SCHEEPDOG: programming electric cues to dynamically herd large-scale cell migration

“…Specifically, our results support the hypothesis that there are two key timescales governing electrotaxis: (1) rapid sensing of the electric field (<10 sec), and (2) slower cellular polarization and migrational response (30 sec to minutes). This separation of scales also occurs in chemotaxis, which has been shown to share certain overlapping signaling and migration infrastructure with electrotaxis (Gao et al, 2015). Our data in Figure 4 that show keratinocytes moving diagonally at 45°in response to rapid and symmetrically alternating X-and Y-direction stimulation (i.e.…”

Nitrogen and group-IV (Si, Ge) vacancy color centres in nano-diamonds: photoluminescence study at high temperature (25 °C–600 °C)

“…Thermometry applications are one of the potential applications of color centres in diamonds [6][7][8][9][10]. Most of these applications concern precise temperature sensors around room temperature in living organisms based on the thermal dependence of their photoluminescence spectra [8,10].…”

“…Thermometry applications are one of the potential applications of color centres in diamonds [6][7][8][9][10]. Most of these applications concern precise temperature sensors around room temperature in living organisms based on the thermal dependence of their photoluminescence spectra [8,10]. NV centers however suffer of low intensity of its zero-phonon line (ZPL line) notably around room temperature, which complicates line position measurements [8,[10][11][12][13][14][15][16][17].…”

“…Most of these applications concern precise temperature sensors around room temperature in living organisms based on the thermal dependence of their photoluminescence spectra [8,10]. NV centers however suffer of low intensity of its zero-phonon line (ZPL line) notably around room temperature, which complicates line position measurements [8,[10][11][12][13][14][15][16][17]. ZPL line position of NV centres is also dependent on other factors such as strain and impurities.…”

The genomic basis of electrotaxis inDictyostelium discoideum: Electric field sensitive amino acids are dynamically encoded en masse for the streaming-stage proteome

“…Furthermore, more recent studies have also begun to disentangle the specific proteins involved in electrotaxis versus chemotaxis (COATES and HARWOOD 2001;ZHAO et al 2002;SHANLEY et al 2006;MYRE et al 2011;WESSELS et al 2014). More recently, systematic genetic screens for genes underlying electrotaxis have also been conducted (GAO et al 2015). However, in principle, diverse cellular proteins involved in cell motility, directional orientation, regulation of membrane current flow, and other signaling systems will likely evolve to be oriented or subcellularly localized in an optimal fixed relationship to the direction of electrotaxis and/or cell polarity ( Fig.…”