title: Shedding new light on the molecular architecture of oocytes using a combination of synchrotron Fourier transform-infrared and Raman spectroscopic mapping.
abstract: Synchrotron Fourier transform-infrared (FT-IR) and Raman microspectroscopy were applied to investigate changes in the molecular architecture of mouse oocytes and demonstrate the overall morphology of the maturing oocyte. Here we show that differences were identified between immature mouse oocytes at the germinal vesicle (GV) and mature metaphase II (MII) stage when using this technology, without the introduction of any extrinsic markers, labels, or dyes. GV mouse oocytes were found to have a small, centrally located lipid deposit and another larger polar deposit of similar composition. MII oocytes have very large, centrally located lipid deposits. Each lipid deposit for both cell types contains an inner and outer lipid environment that differs in composition. To assess interoocyte variability, line scans were recorded across the diameter of the oocytes and compared from three independent trials (GV, n = 91; MII, n = 172), and the data were analyzed with principal component analysis (PCA). The average spectra and PCA loading plots show distinct and reproducible changes in the CH stretching region that can be used as molecular maturation markers. The method paves the way for developing an independent assay to assess oocyte status during maturation providing new insights into lipid distribution at the single cell level.
authors.affiliation: Centre for Biospectroscopy and School of Chemistry and Monash Immunological and Stem Cell Laboratories, Monash University, Victoria 3800, Australia. bayden.wood@sci.monash.edu.au
authors.forename: Bayden R
authors.initials: BR
authors.lastname: Wood
authors.forename: Tatyana
authors.initials: T
authors.lastname: Chernenko
authors.forename: Christian
authors.initials: C
authors.lastname: Matthäus
authors.forename: Max
authors.initials: M
authors.lastname: Diem
authors.forename: Connie
authors.initials: C
authors.lastname: Chong
authors.forename: Uditha
authors.initials: U
authors.lastname: Bernhard
authors.forename: Cassandra
authors.initials: C
authors.lastname: Jene
authors.forename: Alice A
authors.initials: AA
authors.lastname: Brandli
authors.forename: Don
authors.initials: D
authors.lastname: McNaughton
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Tobin
authors.forename: Alan
authors.initials: A
authors.lastname: Trounson
authors.forename: Orly
authors.initials: O
authors.lastname: Lacham-Kaplan
mesh_terms: D000818:Animals; D005260:Female; D008055:Lipids / Q000032:analysis; D008677:Metaphase; D051379:Mice; D009865:Oocytes / Q000737:chemistry* / Q000166:cytology*; D009866:Oogenesis; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*
chemical_list: D008055:Lipids