| Somites are integral to the formation and function of vertebrae in Danio rerio. Found in early development stages, somites ultimately determine how many vertebrae a fish will have. Previous research has shown that fish raised in lower temperature environments have more vertebrae; fish raised in higher temperatures have fewer. If vertebral number is affected by these temperature changes, it could be logically assumed that their precursors would also be affected. This experiment looked at the relationship between temperature and somite development in early stage zebrafish. It was hypothesized that the number and lengths of somites vary based on the temperatures in which development occurs. To test this hypothesis, eggs were collected and treated at various stages of development (early cleavage, early gastrulation, mid-gastrulation, and early somitogenesis) and four different temperatures ranging from 24.5 to 30.5°C. Fish were either antibody stained or cleared and stained at two distinct developmental stages to visualize the size and number of the somites or vertebrae. Results showed a variation in both number and length, with lower temperature specimens having more, shorter somites and vertebrae, and higher temperature specimens having fewer, longer somites and vertebrae. Additionally, fish were treated with varying Retinoic Acid and DEAB concentrations to provide a comparison model for the ways in which somitogenesis can be altered. Our results suggest that temperature and retinoic acid have little to no effect on expression of the clock genes and instead likely affect the retreat of the wavefront. |
