Production of haploid and diploid androgenetic zebrafish (including methodology for delayed in vitro fertilization).

Publisher Summary This chapter describes how to produce androgenotes, how they have been used, and their future potential. It describes two procedures that are required for androgenesis, but which can also be used for other applications: one is the technique of delayed in vitro fertilization, and the other is the technique of interfering with the first mitotic division to double the chromosome complement. Androgenetic haploid and diploid zebrafish larva can be efficiently produced. The production of both andro- and gynogenetic fish indicates that the irreversible inactivation of genes essential for development by parent-of-origin-genome imprinting does not occur in zebrafish, in contrast to some mammals. The success rate in producing haploid androgenotes with nearly normal morphology should make them suitable for some types of genetic screens. Being able to delay the fertilization of zebrafish eggs for periods up to a few hours after they are extruded from the female can facilitate experiments that involve in vitro fertilization. It allows manipulations prior to fertilization; it aids studying fertilization itself; and it can also provide working time for postfertilization manipulations.