Genetic inactivation of Leuciscus idus L. (ide) oocytes using UV irradiation

Oocytes of Leuciscus idus were genetically inactivated using ultraviolet (UV) irradiation. Eggs for the experiment were obtained from dark-coloured females, whereas milt was taken from yellow-coloured (recessive marker) males. The survival at the eleutheroembryo stage (free embryo) in all experimental groups fertilized with genetically inactivated spermatozoa was much lower than in control groups. All haploid embryos showed morphological abnormalities, such as a stunted body and a poorly formed retina, and the condition was referred to as the haploid syndrome. The androgenetic origin (haploid or diploid embryos) was checked using a recessive colour marker ('blond'). The optimal doses of UV irradiation were 3,456-4,608 Jm(-2) at which almost 100% haploid embryos were produced at a hatching rate of >15%. Lower UV-ray doses influenced abnormal embryo development. Ploidy level recognition showed a typical value of mean active nucleoli per cell in haploid and diploid (control fish and spontaneous androgenotes) specimens. Abnormal dark embryos were classified as aneuploids.