Fig. 2

The sq198 mutation causes cell cycle arrest and cell apoptosis in the digestive organs. (A–D) BrdU incorporation assay showed that, at 3.5 dpf, the number and ratio of BrdU positive cells were obviously reduced in the digestive organs of the sec13^sq198 mutant (mu) compared with the wild-type (WT). (A) Transverse section of the wild-type control through the liver (lv), intestine (in) and pancreas (pa). (B) Transverse section of a mutant embryo through the liver (lv) and intestine (in). (C) Transverse section of a mutant through the intestine (in) and pancreas (pa). (D) Histogram showing the ratios of BrdU positive cells versus total cells in a specific organ. Data were obtained from sections derived from three wild-type and three sec13^sq198 mutant embryos, respectively. S: somite, L: liver, I: intestine, P: pancreas; **: P<0.01. (E–G) TUNEL assay showing cell apoptosis (cells in red) in wild-type (WT) (E) and mutant (mu) (F) cryosections. Data shown in (G) were obtained by counting apoptotic cells against total cells in a specific organ (e.g., intestine) in sections from three wild-type and three mutant embryos, respectively. *: P<0.05; **: P<0.01.DAPI was to stain the nuclei. G, gut; L, liver; P, pancreas; S, somite.