Production of tetraploid and homozygous diploid amphibians by suppression of first cleavage

Tetraploid and genetically homozygous diploid Xenopus can be produced conveniently, in large numbers, by suppressing the first cleavage division of eggs through the application of hydrostatic pressure. The pressure‐induced disruption of the mitotic spindle during the first division of a diploid zygote of the African clawed toad results in a tetraploid embryo. A homozygous diploid embryo can be derived by inhibiting the first cleavage of a parthenogenetically activated haploid egg. Both tetraploid and homozygous diploid larvae are viable and successfully undergo metamorphosis.