Support Cells Are Multipotent Progenitors

(A and B) (A) Horizontal and (B) lateral views of a neuromast (NM).

(C–H) Quadruple transgenic larvae express the mantle cell (MC) marker sqet20 (F, green), the hair cell (HC) marker sqet4 (G, cytoplasmic green), the cell membrane marker cldnb:lynGFP (G), and the nuclear maker cldnb:H2A-mCherry (H).

(I) Still images of a time-lapse of a homeostatic NM (Movie S1). Split images show different focal planes. Numbers in NMs label the progenitors shown in (J). Time = hours: minutes.

(J) Lineage analysis of the mitotic events in (I) and Movie S1.

(K) Time-lapse of a regenerating NM (Movie S2B). CD1 is shown in Movie S2C.

(L) Lineage analysis in a regenerating NM (Figure 1K; Movie S2).

(M) SCs self-renew or differentiate into two hair cells: Quantification of lineages of three time-lapse movies of regenerating NMs from Figures S1F–S1H.

(N) Proliferation dynamics during regeneration. Amplifying divisions occur first (p < 0.0001, Fisher’s exact test).

(O) Proliferating cells and their progeny do not actively move in a regenerating NM. Lineages from Figure 1 are color-coded: red: amplifying cell divisions, green: differentiation, blue: MC divisions (Movie S3). mCherry nuclei are in gray.

(P) Vectors show directions and distances of cell displacement before mitosis (metaphase) for every cell division recorded during the first 24 hr in Figures S1F–S1H). Central HC progenitors are not displaced.

(Q) Vectors show cell displacements of one of the daughter SCs back to their original positions. Displacements for P and Q are quantified in Figure S1I.

Scale bars represent 10 µm.

See also Figure S1; Movies S1, S2, and S3.