title: Revisiting rat spermatogenesis with MALDI imaging at 20-microm resolution.
abstract: Matrix-assisted laser desorption/ionization (MALDI) molecular imaging technology attracts increasing attention in the field of biomarker discovery. The unambiguous correlation between histopathology and MALDI images is a key feature for success. MALDI imaging mass spectrometry (MS) at high definition thus calls for technological developments that were established by a number of small steps. These included tissue and matrix preparation steps, dedicated lasers for MALDI imaging, an increase of the robustness against cell debris and matrix sublimation, software for precision matching of molecular and microscopic images, and the analysis of MALDI imaging data using multivariate statistical methods. The goal of these developments is to approach single cell resolution with imaging MS. Currently, a performance level of 20-μm image resolution was achieved with an unmodified and commercially available instrument for proteins detected in the 2-16-kDa range. The rat testis was used as a relevant model for validating and optimizing our technological developments. Indeed, testicular anatomy is among the most complex found in mammalian bodies. In the present study, we were able to visualize, at 20-μm image resolution level, different stages of germ cell development in testicular seminiferous tubules; to provide a molecular correlate for its well established stage-specific classification; and to identify proteins of interest using a top-down approach and superimpose molecular and immunohistochemistry images.
authors.affiliation: INSERM U625, Proteomics Core Facility Biogenouest, Campus de Beaulieu, Université de Rennes I, F-35042 Rennes, France.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Lagarrigue
authors.forename: Michael
authors.initials: M
authors.lastname: Becker
authors.forename: Régis
authors.initials: R
authors.lastname: Lavigne
authors.forename: Sören-Oliver
authors.initials: SO
authors.lastname: Deininger
authors.forename: Axel
authors.initials: A
authors.lastname: Walch
authors.forename: Florence
authors.initials: F
authors.lastname: Aubry
authors.forename: Detlev
authors.initials: D
authors.lastname: Suckau
authors.forename: Charles
authors.initials: C
authors.lastname: Pineau
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D007150:Immunohistochemistry; D007834:Lasers; D008297:Male; D008954:Models, Biological; D057054:Molecular Imaging / Q000379:methods*; D008969:Molecular Sequence Data; D021381:Protein Transport; D011506:Proteins / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015203:Reproducibility of Results; D012671:Seminiferous Tubules / Q000166:cytology / Q000378:metabolism; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*; D013091:Spermatogenesis
chemical_list: D011506:Proteins