caa a22 4500 467983291 CHVBK 20180323112524.0 cr unu---uuuuu 170328e19900501xx s 000 0 eng 10.1007/BF00210808 doi (NATIONALLICENCE)springer-10.1007/BF00210808 Prophase of meiosis in human spermatocytes analysed by EM microspreading in infertile men and their controls and comparisons with human oocytes [Elektronische Daten] [R. Speed, A. Chandley] Summary: Observations at the electron microscope (EM) level have been made on 1883 primary spermatocytes from 40 chromosomally normal subfertile men and 566 spermatocytes from 10 fertile controls, using the technique of microspreading. Spermatocytes of infertile men in general showed greater indications of degeneration including higher levels of background silver deposition, nucleolar organising region — XY associations, fragmentation of synaptonemal complexes and overproduction of XY excrescences. A few oligospermic men also showed an immature morphology of the XY pair and/or a reduced extent of XY synapsis. Dissociation of the sex chromosome axes at prophase was found to occur with a much lower frequency than that recorded for separated X and Y chromosomes at metaphase I. In a single spermatocyte, synaptonemal complex formation was observed between Xqter and Yqter, a situation that could enable rare XqYq interchange. A proteinaceous stalked body exists on the Y axis towards its non-pairing end; this structure might have a functional relationship with the gene for spermatogenesis, (AZF), located at the euchromatin/heterochromatin interface. Compared with human oocytes, spermatocytes show fewer anomalies of synapsis, i.e. asynapsed segments or whole axes, non-homologous associations, interchanges, interlocks. These latter data agree well with findings from the mouse. Springer-Verlag, 1990 Speed R. MRC Human Genetics Unit, Western General Hospital, EH4 2XU, Edinburgh, UK aut Chandley A. MRC Human Genetics Unit, Western General Hospital, EH4 2XU, Edinburgh, UK aut Human Genetics Springer-Verlag 84/6(1990-05-01), 547-554 0340-6717 84:6<547 1990 84 439 https://doi.org/10.1007/BF00210808 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00210808 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Speed R. MRC Human Genetics Unit, Western General Hospital, EH4 2XU, Edinburgh, UK aut NATIONALLICENCE 700 1- Chandley A. MRC Human Genetics Unit, Western General Hospital, EH4 2XU, Edinburgh, UK aut NATIONALLICENCE 773 0- Human Genetics Springer-Verlag 84/6(1990-05-01), 547-554 0340-6717 84:6<547 1990 84 439 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer