title: Imaging of human meiotic chromosomes by scanning near-field optical microscopy (SNOM).
abstract: Centromeres and telomeres are key structures of mitotic and meiotic chromosomes. Especially telomeres develop particular structural properties at meiosis. Here, we investigated the feasibility of scanning near-field optical microscopy (SNOM) for light-microscopic imaging of meiotic telomeres in the sub-hundred nanometer resolution regime. SNOM was applied to visualise the synaptonemal complex (SC) and telomere proteins (TRF1, TRF2) after differential immuno-fluorescent labelling. We tested and compared two different preparation protocols for their applicability in a SNOM setting using micro-fabricated silicon nitride aperture tips. Protocol I consisted of differential labelling of meiotic chromosome cores (SC) by SCP3 immuno-fluorescence and telomeres by TRF1 or TRF2 immuno-fluorescence, while protocol II combined absorption labelling with alkaline phosphatase substrates of cores with fluorescent labelling of telomeres. The results obtained indicate that protocol I reveals a better visualisation of structural (topographic) details than protocol II. By means of SNOM, meiotic chromosome cores could be visualised at a resolution overtopping that of far-field light microscopy.
authors.affiliation: Department of Single Cell and Single Molecule Techniques, Institute of Molecular Biotechnology, P.O. Box 100813, D-07708 Jena, Germany. mihaus@ukl.uni-frieburg.de
authors.forename: Michael
authors.initials: M
authors.lastname: Hausmann
authors.forename: Bodo
authors.initials: B
authors.lastname: Liebe
authors.forename: Birgit
authors.initials: B
authors.lastname: Perner
authors.forename: Martin
authors.initials: M
authors.lastname: Jerratsch
authors.forename: Karl-Otto
authors.initials: KO
authors.lastname: Greulich
authors.forename: Harry
authors.initials: H
authors.lastname: Scherthan
mesh_terms: D002877:Chromosomes, Human / Q000648:ultrastructure*; D005455:Fluorescent Antibody Technique; D006801:Humans; D008297:Male; D008540:Meiosis; D018625:Microscopy, Atomic Force / Q000379:methods*; D013090:Spermatocytes / Q000648:ultrastructure; D013573:Synaptonemal Complex / Q000648:ultrastructure*; D016615:Telomere / Q000648:ultrastructure*; D035321:Telomeric Repeat Binding Protein 1 / Q000378:metabolism; D035341:Telomeric Repeat Binding Protein 2 / Q000378:metabolism
chemical_list: D035321:Telomeric Repeat Binding Protein 1; D035341:Telomeric Repeat Binding Protein 2