Figure 6.

Subtle effect of PCDH19 loss on the total minimum migration distance of MGE explants-derived INs might arise from disturbed migration polarity. (A) A schematic of the ex vivo MGE explant electroporation setup to investigate the effect of PCDH19 KO in MGE-derived IN. (B) Total minimum migration distance “d” was assessed after 48 h of electroporation in Dlx5/6-CRE-IRES-eGFP MGE explants with PCDH19KO RNPs co-electroporated with tdTomato. Minimum distance capacity was analyzed in electroporated neurons (red) measuring ‘d' in MGE-derived IN (green). (C,D) Representative images of electroporated and cultured explants 48 h post electroporation of PCDH19KO RNP (C) and control Cas9 (D). (E) A dot plot depicting tdTomato⁺ IN-related minimal distance from the explant edge. Each dot represents one electroporated neuron in the respective condition; colors of the dots relate to different explants. Significantly shorter distance from the explant edge could be measured between PCDH19KO and control (the Mann–Whitney U test, ^*p < 0.05). (F) Quantification of TdTomato neurons per bin normalized against the total amount of TdT neurons per bin showed non-significant difference per bin (the Mann–Whitney U test, followed by multiple false discovery rate corrections). (G) Polarity with respect to the explant of more than 120 TdTomato neurons was assessed in 4 explants, showing significantly more neurons migrating toward the explant in the PCDH19KO experimental condition. (Two-way repeated measures ANOVA with Holm-Sidak post hoc comparison, ^*p < 0.05). (H–J) Boxplots depicting TdTomato⁺ neuron-associated primary branch length (H), average branch length (I), and cable length (J) measurements in control and PCDH19KO conditions. No significant differences could be detected in these morphology-associated aspects. DIV, days in vitro; IN, interneuron; RNP, ribonucleotide protein; ns, not significant; scale bar: 500 μm.