Abstract
Vitellogenins are a family of yolk proteins that are by far the most abundant among oviparous animals. In the model nematode Caenorhabditis elegans, the 6 vitellogenins are among the most highly expressed genes in the adult hermaphrodite intestine, which produces copious yolk to provision eggs. In this article we review what is known about the vitellogenin genes and proteins in C. elegans, in comparison with vitellogenins in other taxa. We argue that the primary purpose of abundant vitellogenesis in C. elegans is to support post-embryonic development and fertility, rather than embryogenesis, especially in harsh environments. Increasing vitellogenin provisioning underlies several post-embryonic phenotypic alterations associated with advancing maternal age, demonstrating that vitellogenins can act as an intergenerational signal mediating the influence of parental physiology on progeny. We also review what is known about vitellogenin regulation – how tissue-, sex- and stage-specificity of expression is achieved, how vitellogenins are regulated by major signaling pathways, how vitellogenin expression is affected by extra-intestinal tissues and how environmental experience affects vitellogenesis. Lastly, we speculate whether C. elegans vitellogenins may play other roles in worm physiology.
Highlights
VITELLOGENINS ACROSS THE TREE OF LIFEVitellogenins are the principal yolk proteins by which oviparous animals supply nutrients to support the development of their progeny
These results suggest that skn-1 regulates vitellogenin mobilization as part of a response to acute oxidative stress
They transport a variety of lipids and micronutrients from adult tissues to oocytes
Summary
Vitellogenins are the principal yolk proteins by which oviparous animals supply nutrients to support the development of their progeny. Four yolk polypeptides are found in C. elegans - two larger polypeptides with a molecular weight of around 170 kDa (YP170A and YP170B) and two smaller polypeptides at around 115 kDa and 88 kDa (YP115 and YP88, respectively) These polypeptides associate to form 2 distinct large oligomeric lipoprotein complexes. Vit-1, vit-2, vit-3, vit-4, and vit-5 all have exceptionally short 5 UTRs (Spieth et al, 1985), ranging from 9–11 bp This may be related to the presence of potential stem-loop forming structures at the 5 end of all the vitellogenins, highly conserved between C. elegans and C. briggsae, that could serve to impede translation (Zucker-Aprison and Blumenthal, 1989), potentially mediating post-translational regulation of vitellogenin expression. Such a strong preference for certain codons is typical of other abundantly expressed nematode genes, such as collagen, actin or myosin
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
