HUMAN GAMETES AND ZYGOTES STUDIED BY NONRADIOACTIVE INSITU HYBRIDIZATION

A nonradioactive in situ hybridization technique was applied to human gametes and abnormally fertilized or developed zygotes. Using haptenized chromosome-specific probes, visualization was obtained using immunocytochemistry to achieve a fluorescent stain on specific hybrids. Using a chromosome 1 specific DNA probe, almost all spermatozoa gave a positive result. i.e., one hybridization signal per cell could be observed. Furthermore. it was possible to identify sperm cells with two spots, sug-gesting nondisjunction. Two cleavage arrested embryos from different patients showed both: two brightly fluorescent spots and two weaker spots with the same DNA probe. Using a Y-specific DNA probe the percentages of positive spermatozoa from the normal males ranged between 48.1% and 49.1%. In an embryo with Tour grossly haploid chromosome sets, three fluorescent spots were obtained with the Y-specific DNA probe, indicating the penetration of three spermatozoa. © 1990 S. Karger AG, Basel.