Temporal expression of membrane antigens during mouse spermatogenesis

Abstract

Spermatogenic cells at advanced stages of differentiation, including pachytene primary spermatocytes, round spermatids and residual bodies of Regaud and mature spermatozoa, contain common antigenic membrane components which are not detected before the pachytene stage of the 1st meiotic prophase. These surface constituents are not detected on isolated populations of primitive type A spermatogonia, type A spermatogonia, type B spermatogonia, preleptotene primary spermatocytes or leptotene and zygotene primary spermatocytes. These results were demonstrated by immunofluorescence microscopy, by complement-mediated cytotoxicity, and by quantitative measurements of immunoglobulin (Ig) receptors on the plasma membranes of all cell populations examined. The cell surface antigens detected on germ cells are not found on mouse thymocytes, erythrocytes or peripheral blood lymphocytes as determined by immunofluorescence and by cytotoxicity assays. The absorption of antisera with kidney and liver tissue does not reduce the reactivity of the antibody preparations with spermatogenic cells, indicating that these antigenic determinants are specific to germ cells. This represents the 1st direct evidence for the ordered temporal appearance of plasma membrane antigens specific to particular classes of mouse spermatogenic cells. It appears that at late meiotic prophase, coincident with the production of pachytene primary spermatocytes, a variety of new components are inserted into the surface membranes of developing germ cells.