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Fig. 2
Construction of the Tg(ef1α:xbp1?-gfp) transgene and expression of XBP1?-GFP in live zebrafish embryos. (A) A partial zebrafish xbp1 cDNA sequence (239 bp) containing the 26 nt IRE1 target sequence was cloned upstream of the EGFP coding sequence. A myc-tag sequence was also included in frame at 5′ end of the xbp1 sequence. Under normal conditions without ER stress, the xbp1?-gfp transcripts are not spliced and protein translation stops prior to the GFP coding sequence. Upon ER stress, the 26 nt IRE1 target sequence is spliced out from the xbp1?-gfp mRNA transcripts, leading to a frame shift and the expression of the XBP1Δ-GFP fusion protein. (B) Expression of the XBP1?-GFP in live zebrafish embryos. XBP1?-GFP expression was directly observed in the F1 transgenic zebrafish embryos from one cell stage to 24 hpf. A strong XBP1?-GFP expression was observed in transgenic embryos with the transgene derived maternally. In contrast, transgenic embryos with paternally derived transgene showed no XBP1?-GFP expression from one cell stage to 12 hpf. A weak expression was detected at 24hpf. Non-transgenic fish embryos were used as control.
Reprinted from Mechanisms of Development, 137, Li, J., Chen, Z., Colorni, A., Ucko, M., Fang, S., Du, S.J., A transgenic zebrafish model for monitoring xbp1 splicing and endoplasmic reticulum stress in vivo, 33-44, Copyright (2015) with permission from Elsevier. Full text @ Mech. Dev.