DNA-PLOIDY ABNORMALITIES IN RABBIT PREIMPLANTATION EMBRYOS ARE NOT INCREASED BY CONDITIONS ASSOCIATED WITH IN-VITRO CULTURE

Possible adverse effects of in vitro culture-associated physical facto rs were studied in 3- and 4-day-old rabbit embryos. Laboratory conditi ons were mimicked by exposure to visible light (320-740 nm, 1600 lx) o r decreased temperature (22 +/- 1 degrees C). Embryos were exposed for a 24-hr period followed by either immediate evaluation or an addition al 24 hr of standard in vitro culture (darkness, 37 degrees C) and eva luation thereafter. Effects were assayed by cytophotometric measuremen t of the DNA content in Feulgen-stained cell nuclei and by cell number . The incidence of DNA aneuploid embryos and DNA aneuploid cell nuclei per embryo, as well as the average nuclear DNA content, was not signi ficantly different between exposed embryos and controls. Both in vitro culture and reduced temperature caused a decrease in cell number. The temperature-induced cell number decrease was reversible within 24 hr after return to 37 degrees C. These results demonstrate that physical factors associated with in vitro culture do not increase DNA ploidy ab normalities in cultured preimplantation embryos. (C) 1998 Wiley-Liss, Inc.