Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

The expression and localization of vitellogenin (VTG) receptor (VTGR) mRNA were identified throughout ovarian development in the rainbow trout, Oncorhynchus mykiss. Northern blot confirmed the presence of a transcript (approximately 3.9 kilobases [kb]) that was specific to the ovary. The expression of VTGR mRNA varied throughout ovarian development and was highest in previtellogenic ovaries and in ovaries at the onset of vitellogenesis containing ovarian follicles (OF) from 35 to 600 microm in diameter. In situ hybridization using 35S riboprobes showed that the transcription of the VTGR gene was initiated in OF measuring 45-50 microm in diameter, with transcripts being exclusively localized in the ooplasm. A dramatic increase in mRNA synthesis occurred during previtellogenic growth (OF from 50 to 200 microm); this was followed by a gradual decrease during the vitellogenic growth phase. VTGR mRNA was not detected in OF greater than 1000 microm in diameter (oocytes actively sequestering VTG). Immunocytolocalization of yolk proteins derived from VTG demonstrated that oocytes started to sequester VTG when they were around 300 microm in diameter, shortly after the time of maximal density of VTGR mRNA in the ooplasm. The timing of transcription of the VTGR gene, predominantly during previtellogenesis, suggests that the VTGR is recycled to the oocyte surface during the vitellogenic growth phase.


Journal article


Biol Reprod

Publication Date





1057 - 1068


Animals, Autoradiography, Blotting, Northern, Egg Proteins, Female, Image Processing, Computer-Assisted, Immunohistochemistry, In Situ Hybridization, Microscopy, Electron, Oncorhynchus mykiss, Oogenesis, Ovarian Follicle, RNA Probes, RNA, Messenger, Receptors, Cell Surface, Tissue Fixation