Figure 4. Trans-adhesive interaction via CD44ECD between xanthoblasts and macrophages in airineme extension.

(A) S2 cells were transfected with constructs to express actin-mCherry (control), wild-type cd44a-mCherry, or cd44aTMICD-mCherry. Within 1 hour of rotary culture, cell aggregates were formed by those expressing the wild-type cd44a (white arrowheads). (B) Quantification of the transfected cells found within clusters relative to the total numbers of transfected cells in 3 replicate cultures, (F(₂, ₆)=45.50, P=0.0002). (C) S2 cells were co-transfected with constructs expressing wild-type cd44a-mCherry and cd44aTMICD-EGFP at ratios of 1:0 (control), 1:1 and 1:3, (F(₂, ₆)=13.7, P=0.0058). Corresponding images can be found in Fig. S3. (D) Overexpressing cd44aTMICD in both xanthophore lineages and macrophages resulted in a significant reduction in airineme extension frequency. Statistically significant results were evaluated using one-way ANOVA, followed by a Tukey’s HSD post hoc test or a Student’s t-test. Scale bars: 100μm. Error bars indicate mean ± SEM.