title: Ubiquitin-based sperm assay for the diagnosis of male factor infertility.
abstract: Sperm morphology is correlated with fertility in men, yet the existing, subjective sperm morphology assays provide only a limited insight into patients' infertility. Here, we provide the experimental background for a new, objective and automated semen assay, based on the cross-reactivity of defective human spermatozoa with antibodies against a proteolytic marker peptide, ubiquitin. Using immunofluorescence and flow cytometry, we screened the spermatozoa from 17 infertility patients and two fertile donors for their cross-reactivity with anti-ubiquitin antibodies. Thirteen out of 17 patients, but neither of two fertile donors, displayed an increased binding of anti-ubiquitin antibodies to sperm surface, that reflected the occurrence of abnormalities in these samples and was corroborated by available clinical data. Highest correlation coefficient (r = -0.432) was obtained with the cleavage rate after IVF. The contribution of male factor was revealed in several couples previously diagnosed with idiopathic infertility. Ubiquitin-cross-reactive sperm-surface proteins thus seem to be a universal marker of semen abnormalities, including sperm head and tail defects and semen contaminants such as spermatids, leukocytes and cellular debris. We propose that the sperm-ubiquitin tag immunoassay (SUTI) may be a valuable diagnostic tool in treatment of male factor and idiopathic infertility.
authors.affiliation: Oregon Regional Primate Research Center, and Departments of Cell-Developmental Biology and Obstetrics-Gynecology, Oregon Health Sciences University, 505 N.W. 185th Avenue, Beaverton, OR 97006, USA. sutovsky@ohsu.edu
authors.forename: P
authors.initials: P
authors.lastname: Sutovsky
authors.forename: Y
authors.initials: Y
authors.lastname: Terada
authors.forename: G
authors.initials: G
authors.lastname: Schatten
mesh_terms: D015415:Biomarkers; D016022:Case-Control Studies; D003429:Cross Reactions; D005260:Female; D005434:Flow Cytometry; D005455:Fluorescent Antibody Technique; D006801:Humans; D007248:Infertility, Male / Q000175:diagnosis*; D008297:Male; D013094:Spermatozoa / Q000276:immunology / Q000378:metabolism*; D014452:Ubiquitins / Q000276:immunology / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D014452:Ubiquitins