Meeting Abstract
16.1 Sunday, Jan. 4 Compensatory morphological plasticity in response to low protein diets in mice (Mus musculus) DERRICKSON, EM*; MARINELLI, K; Loyola College; Loyola College ederrickson@loyola.edu
The protein content of food directly impacts the growth and development of animals. Because low protein diets likely are encountered by omnivorous and herbivorous mammals, mice may have evolved adaptations that allow them to compensate for low protein, and thus moderate the impact of diet on fitness. We examined the effect of dietary protein on gut morphology in lactating mice, which have substantial need for nitrogen to support themselves and their dependent young. Mice were maintained on isocaloric diets of 10 or 20% protein during gestation and lactation, and sacrificed at 14 or 21 days of lactation. Data were collected on food consumption, fecal production, gut transit and organ characters. The small intestine significantly increased in length, mass and thickness during the lactation period. In addition, the small intestine significantly increased in thickness (>25%) and mass (>30%) on the low protein diet. Although researchers have shown that mice can modify their guts in response to energetic needs, this study demonstrates that mice also exhibit plasticity in response to decreased nitrogen availability. The modifications of the small intestine during lactation and on low protein diets may reflect a broader strategy by mice to increase assimilation of dietary protein by increasing the surface area for absorption. Organs not involved in protein absorption responded differently; a low protein diet was associated with a smaller cecum, heart, liver and kidney. This indicates that lactating mice also may respond to a low protein diet by breaking down tissue in their body to support the demands of lactation. Further study is needed to determine if intestinal plasticity in response to nitrogen is found primarily in opportunistically breeding omnivorous mice, or if this is a more general strategy.
