eCite Digital Repository

A functional shift of urea-producing site from extraembryonic yolk sac to liver in the developing embryos of two oviparous cartilaginous fishes

Citation

Tagaki, W and Kajimura, M and Tanaka, H and Bell, JD and Hyodo, S, A functional shift of urea-producing site from extraembryonic yolk sac to liver in the developing embryos of two oviparous cartilaginous fishes, Abstract Book for the International Congress on the Biology of Fish, 3-7 August, Edinburgh, Scotland, pp. 228. (2014) [Conference Extract]


Preview
PDF (Takagi et al. (2014) A functional shift of urea-producing site from extraembryonic yolk sac to liver in the developing embryos of two oviparous cartilaginous fishes)
Pending copyright assessment - Request a copy
3Mb
  

Abstract

For adaptation to high-osmolality marine environment, cartilaginous fish retain a high systemic concentration of urea. Although the composition of embryonic body fluid was similar to that in adult fish, urea-producing organ has not been identified in developing embryo. Therefore, we investigated the mRNA expression profiles of ornithine urea cycle (OUC) enzymes in two oviparous species. The expression of OUC enzyme genes was detected in the embryonic body, and remarkably increased to hatching, presumably due to the liver growth. The mRNA expression was also found in extraembryonic yolk sac membrane (YSM). The mRNA level of rate-limiting carbamoyl phosphate synthetase III was much higher in the YSM than that in the embryonic body during early stages of development. Our results demonstrate that the YSM makes an important contribution to the ureosmotic strategy of oviparous embryos, and that a functional shift of urea-producing site from YSM to embryonic liver occurs during the development.

Item Details

Item Type:Conference Extract
Keywords:osmoregulation, elephant fish, yolk, sac
Research Division:Agricultural and Veterinary Sciences
Research Group:Fisheries Sciences
Research Field:Fish Physiology and Genetics
Objective Division:Expanding Knowledge
Objective Group:Expanding Knowledge
Objective Field:Expanding Knowledge in the Biological Sciences
Author:Bell, JD (Dr Justin Bell)
Author:Hyodo, S (Associate Professor Susumo Hyodo)
ID Code:100356
Year Published:2014
Deposited By:Sustainable Marine Research Collaboration
Deposited On:2015-05-13
Last Modified:2015-05-13
Downloads:0

Repository Staff Only: item control page