Determination of Heat and Mutagenic Conditions for Modeling Purifying Selection in Carp Embryos

Тhis study represents the first stage of a research project investigating the potential of heat shock as a tool for purifying fish genomes of slightly deleterious mutations. Experimental offspring of common carp (Cyprinus carpio L.) were obtained by fertilizing eggs with sperm treated with the chemical mutagen N-ethyl-N-nitrosourea (ENU). The half-lethal dose (LD50) of ENU was determined to be 1.6 ± 0.8 mM. Optimal heat-shock conditions, resulting in 50% mortality of native embryos, were established at 37.2 ± 1.4°C for 38.5 ± 1.1 min. Survival rates of embryos and larvae exposed to heat shock during the 22-somite and eye-pigmentation stages were significantly lower in offspring obtained from ENU-treated sperm. The data obtained on the survival of experimental offspring, depending on the stage of embryonic development, temperature, and duration of heat shock, will enable the creation of experimental post-stress carp groups. This will allow for the possibility of using heat shock as a factor in purifying selection.