Her5 is required for the development of the endodermal organs. Wild-type and her5 MO-injected animals at 30 (A–B′), 46 (C, C′), and 76 (D, D′) hpf were analyzed for hhex (A, A′) and prox1 (B, B′) expression, confocal projections in the Tg(gutGFP)s854 line in conjunction with Prox1 (red) and Insulin (blue) expression (C, C′), and Alcam (red) and ABCB11 (green) expression (D, D′). (A, A′) hhex expression in the liver (black arrow) and pancreatic islet (black arrowhead) regions could be detected in only a few cells in her5 MO-injected embryos. (B, B′) prox1 expression in the liver region (white arrow) could only be detected at low levels in her5 MO-injected embryos. (C, C′) At 46 hpf, the formation of the hepatopancreatic duct (white bracket) is initiated in wild-type embryos, whereas in her5 MO-injected embryos, this process was perturbed, resulting in an ambiguous ductal morphology. Note the lack of engulfment of the Insulin-positive endocrine cells (white arrowhead) by the ventral pancreatic bud derived tissue in MO-injected embryos. Black arrowhead points to the liver. (D, D′) ABCB11 expression was almost absent in her5 MO-injected larvae. n = 20 in each set of MO-injections; the percentage of MO-injected embryos/larvae exhibiting the phenotype shown in panel C′ was 60% (n = 12/20), and the one in panel D′ was 60% (n = 12/20). Images A–B′ are dorsal views, anterior to the left; C–D′ are ventral views, anterior to the top.
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