Referee 1's review (J. Victor Small):

Naffar-Abu-Amara et al

Discovery of pro-migratory, cancer associated genes using quantitative microscopy-based screening.


Given the contribution of cell migration to metastasis, a migration assay compatible with genomic screening would be a useful tool. The aim of the present report was to create such a tool, based on a high throughput microscope assay. The authors take advantage of the known property of cells to remove particles from the surface on which they move, producing phagokinetic tracks. New here is the development of a systematic, statistical analysis of the tracks, making possible unbiased comparisons between cell types and treatments. A requirement of this analysis was the parallel development of a reproducible bead assay and image acquisition.The results illustrate the applicability of the method in a candidate screen of genes implicated in breast cancer. The paper is clearly written and presented and will be of interest to those working in the area of cell migration.

Minor points:

The word "Discovery" in the title raises more expectations than probably intended.

Typos:Abstract: BackgrounD
Motile cells clear the beads

Fig 5. The differences for MFGE8 do not seem to qualify as major alterations.

Branched tracks in B16 due to "extension of multiple filopodia". Presumably this should be lamellipodia.

p.9.l.9. To produce persistent tracks, cells must also develop membrane protrusions. The difference therefore seems to be between directional and more random protrusions. This point needs clarification, in line with the following paragraph.

Methods: Statistical analysis. This referee was lost on the explanation of the 80th percentile (admittedly no statistician).

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N.B. These are the comments made by the referee when reviewing an earlier version of this paper. Prior to publication the manuscript has been revised in light of these comments and to address other editorial requirements.