Adult zebrafish as a model organism for behavioural genetics

Abstract

Recent research has demonstrated the suitability of adult zebrafish to model some aspects of complex behaviour. Studies of reward behaviour, learning and memory, aggression, anxiety and sleep strongly suggest that conserved regulatory processes underlie behaviour in zebrafish and mammals. The isolation and molecular analysis of zebrafish behavioural mutants is now starting, allowing the identification of novel behavioural control genes. As a result of this, studies of adult zebrafish are now helping to uncover the genetic pathways and neural circuits that control vertebrate behaviour.

Figure 1

Three-generation breeding scheme for chemically-induced mutant fish. Male fish are mutagenised and then crossed to wild-type females to produce an F1 generation. An F2 generation is made by in-crossing F1 siblings. Dominant behavioural mutants can be identified in this F2 generation (black fish). For recessive mutant carriers, a second in-cross is performed and the progeny screened for behavioural alterations (red fish) - if the inheritance in Mendelian then one quarter of the progeny should show the behavioural defect.

Figure 2

Breeding scheme for the production of insertional mutants in zebrafish. Single-cell to blastula-stage embryos are injected with a mutagen and grown to adulthood. The mature fish are then inbred twice to produce first an F1 and then an F2 generation. Mutants with behavioural phenotypes (black and blue spotted fish) can be identified by in-crossing the F3 fish. The number- and position of insertions can be monitored by western blot and PCR analysis.