The distribution of precursors and biosynthetic enzymes required for Tyrian purple genesis in the hypobranchial gland, gonoduct, an egg masses of Dicathais orbita (Gmelin, 1791) (Neogastropoda: Muricidae)

The biosynthetic origin of Tyrian purple in the adult hypobranchial gland and egg masses of die Muricidae is unknown. Histochemistry and mass spectrometry were employed to determine the distribution of biosynthetic components essential for Tyrian purple precursor synthesis within the hypobranchial gland, gonoduct, egg masses, and larvae of Dicathais orbita, Histochemical correlations suggest that de novo synthesis of the prochromogen, tyrindoxyl sulphate, not only occurs within the hypobranchial gland, but also within the gonoduct, capsule, intracapsular fluid, and encapsulated larvae. The coincidence of tyrindoxyl sulphate and arylsulphatase in the capsule and albumen glands, along with the capsule wall and intracapsular fluid, suggest that the biosynthetic components required for Tyrian purple synthesis are introduced during capsule formation, Overall it appears that the egg mass natural products of the Muricidae arise from a maternal source.