Zebrafish development stages

A detailed description of the stages of zebrafish development has recently been published (32) and the reader who is interested in a detailed look at the key features of this developmental series should read this paper and refer to the Zebrafish Book (33). What follows is a brief description of the key stages of zebrafish development over the first 2-s period—all of the terms and stages are consistent with those used by Kimmel et al. (32) and relate to embryos growing at 28.5°C. 

Figure 7 shows the effect of ectopic administration of T3 to the developing zebrafish embryo. At nontoxic concentration (50 nM), only a moderate fraction (less than 5%) of the zebrafish transcriptome shows significant changes. Ossification, visual processes, and the hematopoietic system were the physiological processes most affected by the treatment, in a pattern consistent with an advancement of the development in these particular functions (Fig. 7b). Genes involved in these three processes are known targets for TDCs during metamorphosis in amphibians, teleost fishes, and lampreys [54—60], and constitute molecular counterparts of different endpoints used to test for TDC in amphibians [56, 58]. Therefore, they are excellent candidates for markers of thyroid disruptors in zebrafish at early developmental stages. Chapter 14 provides a more in-deep description of the developmental effects of thyroid disruption in zebrafish embryos.

Descriptions of zebrafish embryo development and developmental staging have been published elsewhere (12-14). 

Dahm R (2002) Atlas of embryonic stages of development in the zebrafish. In Nusslein-Volhard C, Dahm R (eds) Zebrafish a practical approach. Oxford University Press, New York, NY, pp 59-94... 

The effects of cyanobacterial hepatotoxins and neurotoxins were examined on the embryos of fish and amphibians up to advanced stages of embryonic development. No acute toxic effects were observed after exposure to microcystins, but at the highest applied concentration of microcystin-LR (10 mg/L), morphological effects were detected. AN (400 pg/L) altered the heart rate in zebrafish, but no chronic effects were observed (Oberemm et al. 1999). The effects of cyanobacterial toxins on... 

Fig. 16.3. Zebrafish embryo injected at the one cell stage with a caged mRNA for the transcription factor engrailed and photo-activated 12 h post-fertilisation exhibits an absence of eye development, with permission from Ando et al. [38]...

Kimmel CB, Ballard WW, Kimmel SR, et al. Stages of embryonic development of the zebrafish. Developmental Dynamics. 1995 203(3) 253-310. 

Winter MJ, Redfern WS, ffayfield AJ, et al. Validation of a larval zebrafish locomotor assay for assessing the seizure liability of early-stage development drugs. J Pharmacol Toxicol Methods. 2008 57(3) 176-187. 

Grandel, H., K. Lun, G.J. Rauch, M. Rhinn, T. Kotrowski, C. Houart, P. Sordino, A. Kuchler, S. Schulte-Merker, R. Geisler, N. Holder, S. Wilson and M. Brand. Retinoic acid signaling in the zebrafish embryo is necessary during presegmentation stages to pattern the anterior-posterior axis of the CNS and to induce a pectoral fin bud. Development 129 2851—2865, 2002. 

---