Table 3.

Recruitment of human EGFR-expressing S2 cells into L1-CAM-expressing S2 cell aggregates

Unlabeled S2 cells expressing	DiI-labeled S2 cells expressing	Average of cell clusters with ≥3 labeled cells ± SD (%)	p-Value
human L1-CAM	human L1-CAM	99.6 ± 0.5	<0.0001
human L1-CAM	human EGFR	30.1 ± 8.2	0.0004
human L1-CAM	untransfected	2.5 ± 3.4
Drosophila Fas I	human EGFR	1.0 ± 1.0	0.9860

S2 cells that expressed either human L1-CAM or Drosophila Fasciclin I were mixed and incubated with an equal number of S2 cells, which were labeled with the fluorescent dye DiI and either expressed human L1-CAM, human EGFR, or no exogenous S2 cell protein (not transfected). The final total cell concentration was 1.5 × 10⁶ cells/ml. Cells were aggregated on a shaking platform for 1 h, and cell aggregates, which consisted of at least 10 cells, were evaluated for the presence or absence of three or more DiI-labeled S2 cells. The numbers represent the averages and SDs of the percent of positive cell aggregates from five independent experiments. The statistical analysis was made by comparing the incorporation of DiI-labeled S2 cells to the number of untransfected, DiI-labeled S2 cells into L1-CAM-expressin cell clusters. The paired Student's t test was used and p-values <0.05 were considered to be significant.