Early Zebrafish Development

Gestation and Overview of Development

In comparison to other vertebrates, especially humans, zebrafish development occurs rather rapidly where the majority of embryogenesis occurs by 3 dpf /72 hpf.  You can watch a very cool video that shows the entire process of zebrafish embryogenesis from the 1 cell stage – to hatching at this link (Zebrafish Development from egg to embryo).

Early Embryogenesis:

Zebrafish eggs are telolecithal, which means that a majority of the egg is made up of yolk. Since cleavage can only occur in yolk free zone, this means that cell divisions are not able to completely divide the egg (meroblastic). The first few cell divisions follow a reproducible pattern occurring around every 15 mins. Gastrulation occurs at around ~5.25 hours (50% epiboly) and leads to the formation of all three germ layers (mesoderm, endoderm, and ectoderm) (Gilbert 2014).

 

Chapter 45 – Zebrafish as a Model to Understand Vertebrate Development