Maninder at work in the lab
| |
Maninder at work in the lab |
|
|
Maninder
Virk
Department of Biology Mentor: Terry Derting Title of Presentation: Patterns
of energy allocation in immunochallenged and testosterone-treated white-footed
mice (Peromyscus leucopus). Presented at: Kentucky Academy of Science Annual
Meeting. Virk also presented her research at the MSU Undergraduate Research
Symposium in 2003
The research was supported by: Howard Hughes
Medical Institute
ABSTRACT The cost of mounting an immune response was studied
in normal and testosterone-treated male white-footed mice (Peromyscus
leucopus) that were fed ad libitum. We tested the null hypotheses : 1)
there is no change in metabolic rate during an immunochallenge and 2)
there is no change in energy allocation to other systems during an immunochallenge.
We established four groups of animals: 1) control, 2) testosterone-treated,
3) immunochallenged, and 4) immunochallenged plus testosterone. Injections
of testosterone propionate to elevate the level of testosterone. Immunochallenged
animals were injected with sheep red blood cells (SRBC) and phytohemoglutination
(PHA) to challenge the humoral and cell mediated branches of the immune
system, respectively. To test our first hypothesis we determined the daily
metabolic rate (DMR) and the resting metabolic rate (RMR) of each animal.
To test our second hypothesis we measured the masses of the body organs.
There was a significant increase in RMR in the immunochallenged animals,
but no difference in DMR among groups. Thus, our first hypothesis was
partially supported. Immunochallenge had no significant effect on the
masses of intestinal and vital organs, but was associated with a significant
increase in the masses of the reproductive organs. We, therefore, rejected
our second hypothesis. Our findings indicated that there was a significant
cost associated with mounting an immune response, as indicated by the
increase in RMR. In addition, there was an increase in energy allocation
to the reproductive organs. Thus, under good conditions there was no trade-off
in energy use for immunity and reproduction. Date Modified July, 2003
|