title: Hertwig effect caused by UV-irradiation of sperm of Oryzias latipes (teleost) and its photoreactivation.
abstract: When sperm of the fish Oryzias latipes were irradiated with ultraviolet light and allowed to fertilize normal eggs, the so-called "Hertwig effect" was observed, with a dose-dependent decrease in survival rate at low doses (0-27 J . m-2) but a better survival rate at higher dose ranges. Illumination with visible light after fertilization (10-70 min after insemination) showed the existence of photoreactivation (PR), demonstrating that pyrimidine dimers are a lesion in sperm DNA that is mainly responsible for the UV-caused Hertwig effect. Genetic analysis, in which sperm from a wild-type of this fish was used, showed that, after UV-irradiation at the high dose range, male nuclei did not participate in embryonic development (a gynogenetic haploid condition). Embryos having only a maternal set of chromosomes could develop no further than stage 27. Only the visible light during the early part (until around 20-30 min after insemination, at 25 degrees C) of the single-cell stage was effective for PR; illumination thereafter was not.
mesh_terms: D000818:Animals; D004247:DNA / Q000528:radiation effects*; D004260:DNA Repair / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004625:Embryo, Nonmammalian / Q000528:radiation effects; D005260:Female; D005399:Fishes / Q000235:genetics*; D008027:Light; D008297:Male; D013094:Spermatozoa / Q000528:radiation effects; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D004247:DNA