Fluorescent in-situ hybridization (ISH) to interphase nuclei of human preimplantation embryos has been demonstrated with the X and Y chromosome-specific DNA probes, pBamX7 and pHY2.1, respectively. Assigning the sex on the basis of the number of hybridization signals in the majority of nuclei, the efficiencies with both probes to nuclei from male embryos were considerably higher than those previously reported for pHY2.1 detected by isotopic or conventional non-isotopic methods. Only approximately 15% of nuclei from male embryos failed to hybridize with these probes. With pBamX7, a high incidence (18%) of nuclei with two (or more) signals in embryos classified as males and four signals in a female embryo was observed. In some cases, the double spot nuclei were larger than those with single spots, providing evidence of tetraploidy. The feasibility of using fluorescent ISH for sexing biopsied embryos in couples at risk of X-linked disease and for the preimplantation diagnosis of chromosome abnormalities is discussed.
Among the many potential developments in IVF, four topics are chosen for discussion. New concepts in the regulation of follicle growth should permit the introduction of improved methods of ovarian stimulation, eg through the use of LHRH antagonists or growth factors. Detailed analyses on human capacitation, the nature of sperm-egg binding and sperm maturation in the epididymis will assist the treatment of male infertility. Research on embryos will clarify details of the growth and metabolism of embryos and their cryopreservation, and indicate the preferred methods to diagnose genetic disease in preimplantation embryos. Analyses on embryonic growth to day 10 and beyond, on interactions between uterine stroma and epithelium, and between these tissues and the trophoblast, should clarify the physiology and biochemistry of human implantation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.