Fig. 1

Expression of chata but not chatb genes in the larval zebrafish gut and the construct used to create the transgenic line Tg(chata:GGFF2). A–M: Whole mount in situ hybridization for chata (A–E), chatb (F–I) and nos1 (J–M). The developmental stages are at the top right of each panel. Scale bar: 100 μm. All panels but E are left-side views, and the gut at the level of mid-intestine (black bracket) flanked with the anterior half of the yolk extension (yolk ext.) is shown. Anterior: to the left. In most of the samples chata was not detected in the gut, but in some cases a very weak signal was observed after 72 hpf (panels C, D: black arrowheads). Embryo in E, dorsal view of the head, with anterior to the top. Cranial motor nuclei (which showed a strong signal for chata) are indicated with Roman numerals. In the gut, no signal was detected for chatb (F–I), whereas a strong signal was detected for nos1 in the gut after 60 hpf (K,L,M). N: RT-PCR results for chata, chatb and nos1. "4d" and "6d": The cDNAs from 4- and 6-dpf gut, respectively. "W": The cDNA from whole embryos at 5 dpf. The expected sizes of amplified chata and chatb cDNAs (yellow arrowheads) and the nos1 (white arrowheads) are shown. We detected chata expression, but not chatb, in the developing gut, and both chata and chatb amplified cDNA were found in lane W. nos1 was detected in all lanes. O: A schematic drawing of the construct used to create the transgenic line pTol2 + GGFF-chat 1.5k. The 1.5-kb upstream regulatory region for chata was ligated to gfp-gal4ff fusion (GGFF) cDNA followed by poly A, flanked by Tol2 recognition sites (Tol2-L, R).