The contribution of mutation to variation in temperature-dependent sprint speed in zebrafish, Danio rerio

The contribution of new mutations to phenotypic variation, and the consequences of this variation for individual fitness, are fundamental concepts for understanding genetic variation and adaptation. Here, we investigated how mutation influenced variation in a complex trait in zebrafish, Danio rerio. Typical of many ecologically relevant traits in ectotherms, swimming speed in fish is temperature-dependent, with evidence of adaptive evolution of thermal performance. We chemically induced novel germline point mutations in males and measured sprint speed in their sons at six temperatures (between 16°C and 34°C). Heterozygous mutational effects on speed were strongly positively correlated among temperatures, resulting in statistical support for only a single axis of mutational variation, reflecting temperature-independent variation in speed (faster-slower mode). These results suggest pleiotropic effects on speed across different temperatures, however, spurious correlations arise via linkage..., Individual fish from two treatments were swum in a flume using a step velocity test to assess their sprint speed, Usprint. The file contains 3479 records of Usprint for 594 individuals from 100 families, belonging to either Mutant or Control treatments. Analyses were conducted excluding individuals more than 3SD from the mean of their respective temperature, treatment, flume and block means.,