Viviparous fish, including white-edged rockfish (Sebastes taczanowskii), accumulate substantial yolk mass in the oocytes; however, the details of the molecular mechanisms underlying yolk formation are not yet fully understood, especially concerning multiplicity in the yolk precursor vitellogenin (Vtg). The present study aimed to reveal the hepatic transcriptional profiles of multiple vtg gene transcripts (vtgAa, vtgAb, vtgC) during the reproductive cycle in captive female white-edged rockfish reared in an aquarium under natural photo-thermal conditions. The serum estradiol-17β concentration and the hepatic transcript levels of all vtg subtypes increased with the progress of vitellogenesis; both levels decreased at the beginning of oocyte maturation and remained low during the gestation period. Considering the similarity in the transcriptional profiles of vtg subtypes between Sebastes and Oncorhynchus, along with the differences between Sebastes and Morone, it is suggested that the transcription patterns of multiple vtg genes relate to neither their reproductive modes (viviparity versus oviparity) nor to teleost phylogeny.
Keywords: ovarian development; vitellogenin; viviparity; white-edged rockfish; yolk formation.