Figure 4

 cxcr5  is required and sufficient for regenerative neurogenesis. (A) Heat shock and BrdU scheme for neurogenesis assay in the unlesioned telencephalon. After a sham operation, three daily heat shocks were given before a 10-hour BrdU pulse and sacrifice at 30 days after the sham operation. (B-D) HuC and BrdU immunohistochemistry (IHC) and 4,6-diamidino-2-phenylindole (DAPI) counterstaining on unlesioned telencephalons from non-transgenic (B), Tg(hsp:egfp-t2a-dncxcr5) (C) and Tg(hsp:egfp-t2a-FLcxcr5) (D) animals. Primed and double-primed images are single channels for BrdU and HuC. (E) Quantification graph for relative numbers of HuC and BrdU double positive cells (newborn neurons) in unlesioned telencephalons. Transgenic misexpression of cxcr5 does not alter the constitutive levels of neurogenesis in the adult zebrafish telencephalon. (F) Heat shock and BrdU scheme for neurogenesis assay in lesioned telencephalons. After the lesion, three daily heat shocks were given before a 10-hour BrdU pulse and sacrifice at 30 days after lesioning. (G-I) HuC and BrdU IHC and DAPI counterstaining on unlesioned telencephalons from non-transgenic (G), Tg(hsp:egfp-t2a-dncxcr5) (H) and Tg(hsp:egfp-t2a-FLcxcr5) (I) animals. Primed and double-primed images are single channels for BrdU and HuC. (J) Quantification graph for relative numbers of newborn neurons in lesioned telencephalons. Transgenic misexpression of dominant negative variant of cxcr5 significantly reduces, and full-length cxcr5 significantly increases, the number of newborn neurons after lesioning in the adult zebrafish telencephalon. Scale bars 25 μm; n = 4 telencephalons for each analysis.