Study of the conversion of GDP-mannose into GDP-fucose in Nereids: a biochemical marker of oocyte maturation.
Homogenates of Perinereis cultrifera oocytes were found to transform GDP-D-mannose into another sugar nucleotide. Ultraviolet absorption spectra, chromatographic behaviour, gas-liquid chromatography coupled to mass spectrometry analysis revealed that GDP-D-mannose had been converted into GDP-L-fucose. This conversion is a multi-step reaction as proved by the involvement of two intermediates identified as GDP-4-oxo-6-deoxy-D-mannose and GDP-4-oxo-6-deoxy-L-galactose, this latter being reduced by NADPH to give GDP-L-fucose. It is shown that the enzymatic activities responsible for the conversion of GDP-D-mannose into GDP-L-fucose is recovered only in oocytes and is not present in the other coelomic cells (i.e. coelomocytes). More interesting is the fact that maximum activity is recovered at a well defined stage of the hormone-controlled oogenesis. Thus, this enzymatic system appears as a biochemical marker of the oocyte maturation in P. cultrifera.
D000818:Animals; D001711:Biotransformation; D002854:Chromatography, Paper; D005260:Female; D006154:Guanosine Diphosphate Fucose / Q000096:biosynthesis*; D006155:Guanosine Diphosphate Mannose / Q000378:metabolism*; D013058:Mass Spectrometry; D009243:NAD / Q000502:physiology; D009249:NADP / Q000502:physiology; D009702:Nucleoside Diphosphate Sugars / Q000096:biosynthesis* / Q000378:metabolism*; D009865:Oocytes / Q000254:growth & development / Q000378:metabolism; D010084:Oxidation-Reduction; D011077:Polychaeta / Q000378:metabolism*
D009702:Nucleoside Diphosphate Sugars; D009243:NAD; D006154:Guanosine Diphosphate Fucose; D006155:Guanosine Diphosphate Mannose; D009249:NADP