FT-IR Microspectroscopy on molecular building of Zebrafish oocytes

Zebrafish oocytes growth causes relevant modifications in protein components, in fact, the proteolytic cleavage of vitellogenin. a large sex-specific phospholipoglycoprotein synthesized in the female liver, leads to three main yolk protein components (phosphovitin and lipovitellins 1, 2), present as a complex in the oocyte FT-IR Microspectroscopy could have the potentiality of monitoring these biochemical changes during the Maturation process. Representative spectra for I-II, IIIA, IIIB and IV classes oocytes (Hierarchical Clustering Analysis and Principal Component Analysis) were investigated to find specific vibrational patterns corresponding to different maturation degrees. On going from I-II to IV class oocytes, relevant spectral differences were found with III class exhibiting an intermediate spectroscopic behaviour In particular, the increase of the convoluted band at 2925 cm(-1) (CH2 and CH3 stretching modes), as well as of intensity band ratios at 2926/2954 cm(-1) (v(asym) CH2/CH3), 2854/2873 cm(-1) (v(sym) CH2/CH3) and 1452/1392 cm(-1) (delta CH2/3/v(sym)COO(-)), suggest longer lipidic chains, broadening of Amide I and II bands and absorptions at 1737 (vC=O, phospholipids) and 1157 cm(-1) (vC-O and vC-OH carbohydrates) in lipovitellin and vitellogenin spectra, are present in III and IV classes. (C) 2009 Elsevier B.V. All rights reserved.