| Methods of gynogenesis, androgenesis and polyploidy induction were developed with the aim of genetic improvement in the rainbow trout, the Pacific oyster, the Manila clam and the black scallop. In the trout: · haploid androgenesis was induced by means of a pressure shock applied on diploid eggs, probably at the time of karyogamy. Diploid androgenetic individuals were directly produced from eggs fertilized with sperm from tetraploid male. · a heat shock treatment effective for suppressing the first egg mitosis was developed. This treatment allows the production of homozygous gynogenetic lines (checked using enzyme electrophoresis technique) from eggs inseminated with ultraviolet irradiated sperm. The treatment also induced tetraploidy in eggs normally... |
