Brain transcriptome variation among behaviorally distinct strains of zebrafish (Danio rerio)

Abstract

BackgroundDomesticated animal populations often show profound reductions in predator avoidance and fear-related behavior compared to wild populations. These reductions are remarkably consistent and have been observed in a diverse array of taxa including fish, birds, and mammals. Experiments conducted in common environments indicate that these behavioral differences have a genetic basis. In this study, we quantified differences in fear-related behavior between wild and domesticated zebrafish strains and used microarray analysis to identify genes that may be associated with this variation.ResultsCompared to wild zebrafish, domesticated zebrafish spent more time near the water surface and were more likely to occupy the front of the aquarium nearest a human observer. Microarray analysis of the brain transcriptome identified high levels of population variation in gene expression, with 1,749 genes significantly differentially expressed among populations. Genes that varied among populations belonged to functional categories that included DNA repair, DNA photolyase activity, response to light stimulus, neuron development and axon guidance, cell death, iron-binding, chromatin reorganization, and homeobox genes. Comparatively fewer genes (112) differed between domesticated and wild strains with notable genes including gpr177 (wntless), selenoprotein P1a, synaptophysin and synaptoporin, and acyl-CoA binding domain containing proteins (acbd3 and acbd4).ConclusionsMicroarray analysis identified a large number of genes that differed among zebrafish populations and may underlie behavioral domestication. Comparisons with similar microarray studies of domestication in rainbow trout and canids identified sixteen evolutionarily or functionally related genes that may represent components of shared molecular mechanisms underlying convergent behavioral evolution during vertebrate domestication. However, this conclusion must be tempered by limitations associated with comparisons among microarray studies and the low level of population-level replication inherent to these studies.

Population and sex differences in Drosophila melanogaster brain gene expression

“…melanogaster (~2%) is similar to what has been reported for comparisons of wild and domesticated populations of fish and mammals (~1%) [53,54]. In contrast, comparisons of brain transcriptomes between nursing and foraging bees [55] and male Atlantic salmon with different mating strategies [56] revealed much higher proportions of differentially expressed genes (15% and 35%, respectively).…”

Behavioral and neurogenomic transcriptome changes in wild-derived zebrafish with fluoxetine treatment

“…It is also possible that by utilizing the whole brain, we may not be able to detect some pathways that are differentially expressed in specific regions. It should be noted, however, that whole-brain transcriptome studies still provide important insights into the molecular mechanisms of sex differences and a variety of social behaviors [56,106-114]. Future studies should use transgenic zebrafish or pharmacologically alter expression levels to better characterize the role of a gene.…”

Sex-specific transcriptional responses of the zebrafish (Danio rerio) brain selenoproteome to acute sodium selenite supplementation

“…The process for normalization and filtering of the array followed the methods described in Drew et al (31) (R script for microarray analysis is available as supplemental material: Supplement_1). 1 CEL files containing raw data were processed and analyzed with R software (78) and Bioconductor packages (42).…”