Journal of Comparative Physiology B

, Volume 179, Issue 2, pp 183–192

Measurement of the rate of protein turnover and synthesis in the marsupial Honey possum (Tarsipes rostratus)

Authors

    • School of Animal Biology M092, Centre for Native Animal Research (CNAR)University of Western Australia
  • F. J. Bradshaw
    • School of Animal Biology M092, Centre for Native Animal Research (CNAR)University of Western Australia
Original Paper

DOI: 10.1007/s00360-008-0301-9

Cite this article as:
Bradshaw, S.D. & Bradshaw, F.J. J Comp Physiol B (2009) 179: 183. doi:10.1007/s00360-008-0301-9

Abstract

Rates of protein turnover and synthesis were measured in wild-caught Honey possums (Tarsipes rostratus) in the southwest of Western Australia and compared between males and females with and without pouch young. Possums were injected with 50 μg of 15N-glycine and ammonia collected within 24 h was used as the nitrogen end-product in a single-injection protocol. The overall mean rate of protein synthesis measured was 7.7 ± 0.5 g kg−0.75 day−1, which falls within the range of values reported for other marsupial species. Whole body rates of nitrogen flux and protein synthesis did not vary significantly between males and females with and without young, but females with pouch young showed significantly lower rates of protein synthesis when expressed in relation to metabolic body size. This difference was no longer apparent, however, if the mass of the females was corrected for the estimated mass of the young in the pouch averaging 9.3 ± 1.6 g kg−0.75 day−1 and suggesting that the young should not be considered as part of the metabolic body pool. Whole body rates of protein degradation were significantly reduced in females carrying pouch young, suggesting that protein may be being diverted from the pool to milk production. Calculations indicate that the daily fraction of the female’s nitrogen synthesis rate that needs to be diverted to pouch young to sustain their growth is less than 5%, and may not be detectable with the current methodology.

Keywords

Honey possum Marsupial Protein synthesis Nitrogen Reproduction Nectarivore Turnover

Copyright information

© Springer-Verlag 2008