The Quantitative Genetic Architecture of the Bold-Shy Continuum in Zebrafish, Danio rerio

Abstract

In studies of consistent individual differences (personality) along the bold-shy continuum, a pattern of behavioral correlations frequently emerges: individuals towards the bold end of the continuum are more likely to utilize risky habitat, approach potential predators, and feed under risky conditions. Here, we address the hypothesis that observed phenotypic correlations among component behaviors of the bold-shy continuum are a result of underlying genetic correlations (quantitative genetic architecture). We used a replicated three-generation pedigree of zebrafish (Danio rerio) to study three putative components of the bold-shy continuum: horizontal position, swim level, and feeding latency. We detected significant narrow-sense heritabilities as well as significant genetic and phenotypic correlations among all three behaviors, such that fish selected for swimming at the front of the tank swam closer to the observer, swam higher in the water column, and fed more quickly than fish selected for swimming at the back of the tank. Further, the lines varied in their initial open field behavior (swim level and activity level). The quantitative genetic architecture of the bold-shy continuum indicates that the multivariate behavioral phenotype characteristic of a “bold” personality type may be a result of correlated evolution via underlying genetic correlations.

Combining animal personalities with transcriptomics resolves individual variation within a wild‐type zebrafish population and identifies underpinning molecular differences in brain function

“…Recently, bold–shy behaviour was shown to have a strong heritable component in zebrafish (Oswald et al . ; Ariyomo et al . ), and we produced similar data (Vargas et al ., unpublished data).…”

Individual differences in activity levels in zebrafish (Danio rerio)

“…These individual differences may be utilized in future experimental work in multiple ways. One could “convert” such differences into genetic differences across lines or strains of fish by selectively breeding extreme performers or by inbreeding zebrafish and thus increasing genetic drift (random fixation of alleles) [7, 12]. One could also conduct systematic and comprehensive gene expression analyses [37] and compare the individuals or classes of individuals as defined in the current study to understand the potential biological mechanisms underlying the observed behavioural differences.…”

“…Aggressiveness is often quantified as the number of aggressive encounters using the mirror task [4 – 6, 11]. These behavioural measures have been reported to exist on a continuum with certain individuals scoring high on measures of boldness and/or aggressiveness, while others scoring low [7, 12]. …”

Fluctuations in Evolutionary Integration Allow for Big Brains and Disparate Faces

“…While the original framework of Hansen and Houle56 is based on genetic matrices (G-matrices), P-matrices can be substituted in place of G-matrices if there is enough similarity between the two. In mammals, a close similarity between G and P matrices was strongly evidenced in Marroig, Shirai4 and in fishes, several studies have found significant correlations between G and P matrices575859. Evolvability was estimated using the random skewers method of Cheverud and Marroig60 based on the Lande61 equation (Δz = Gβ) where G is the genetic variance-covariance matrix and β is the selection gradient.…”