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Poster Full Abstracts - Physiology and Aging
Poster board number is above title. The first author is the presenter
327
and the mechanism of the inheritance of metabolic state is still unknown. To determine if parental diet influences progeny metabolism in
Drosophila
, we fed
mature wild type adults either a complete diet or a nutrient depleted diet. We have found that the adult progeny of parents fed the nutrient-depleted diet
display higher levels of triacylglyceride and lower levels of glycogen than the progeny of parents fed the complete diet. These effects are independent of
progeny diet, suggesting that they are the result of an inherited metabolic program. In addition, we see changes in the expression levels of several genes
controlled by the nuclear receptor DHR96 between progeny of parents fed either the complete or nutrient depleted diets. This preliminary data provides the
foundation to study the genetic and molecular mechanisms underlying the transgenerational inheritance of metabolic state in an easily manipulated genetic
system, as well as to understand the physiological effects of parental diet on offspring.
732C
dFatp
Regulates Nutrient Distribution and Long-term Physiology in
Drosophila
.
Alyson Louise Sujkowski, Samantha Morley, Joanna Jennens, Nicole
Piazza, Lindsey Healy, Martin Tinkerhess, Li Zheng, Robert Wessells. Univ Michigan, Ann Arbor, MI.
Nutrient allocation and usage plays an important part in regulating the onset and progression of age-related functional declines. Dietary restriction, for
example, extends lifespan and protects against multiple stresses in various organisms. Endurance exercise, by contrast, extends functionality during aging
without extending maximal lifespan. The discovery of mimetics that replicate positive and additive effects of diet and exercise programs is thus an important
research goal. Here, we describe a dominant mutation in
Drosophila (dFatp)
that alters nutrient distribution by limiting usage of fatty acids.
dFatp
mutants
have increased lifespan and stress resistance, altered feeding behavior and fat storage, increased respiration and increased mobility. Concurrently, mutants
experience impairment of cardiac function. We show that cardiac impairment of mutants is rescued by exercise training without reversing lifespan extension
and present a model to explain these results. These findings establish a novel conserved genetic target for regulating the functional effects of diet and
exercise on the physiology of aging animals.
733A
Impact of Glutamate Dehydrogenase (GDH) and Isocitrate Dehydrogenase (IDH) on Lifespan and Starvation Resistance in Varying Nutrient
Conditions.
Brittany Barnett, Matthew Talbert, Walter Eanes. Ecology and Evolution, SUNY Stony Brook, Stony Brook, NY.
Nutrient state is partly governed by ATP/ADP and metabolic cofactors, which are established by central metabolic enzymes. A fed or fasting state in
secretory neural and endocrine tissues results in molecular profiles that impact lifespan and life history traits. We altered activity of two metabolic enzymes
and investigated impact on lifespan and starvation resistance of
D. melanogaster
in the context of low and high nutrient (LN and HN). Gdh regulates protein
entrance into metabolism, critical in states of starvation or low nutrient intake and regulates NAD+ levels. Idh functions in the TCA cycle and supplies
NADPH. Null alleles, derived from P-element excision, were background replaced and crossed with w; 6326; 1, yielding flies with 70% Gdh activity and
50% Idh activity compared to full alleles also crossed with 6326. To assess interaction of nutrient availability with any lifespan effects, flies were subjected
to HN (16g yeast, 16g sucrose/100 mL H
2
0) or LN (4g yeast, 4g sucrose) cornmeal-based food medium at 25°C (n=400). Starvation studies were run at room
temperature using sealed plastic vials with a damp cotton base (n=200). There was no effect on lifespan regardless of Idh activity on either diet; however, a
calorie restriction effect was observed with LN flies living longer than HN flies. Full activity Idh flies survived starvation ~10 hrs longer than the low
activity flies (p=.031). Again a calorie restriction effect was observed in Gdh flies; however, low activity Gdh flies lived 5 days longer than the full activity
Gdh flies within the LN cohort (p=.020). In addition, low activity Gdh flies survived starvation ~8 hrs longer than the full activity Gdh flies (p=.037). The
data suggest that Gdh is an important mediator of lifespan under LN conditions. On HN, the intake of nutrients may be too great for differences in Gdh
activity to matter. The data also suggest that Idh is not an important mediator of lifespan, but it is of starvation resistance.
734B
Role of Conventional Odorant Receptors in
D.melanogaster
Lifespan and Aging Physiology.
Ceyda Bilgir
1
, Xiaowen Chu
2
, Yuzhong Liu
1
, Brian Y.
Chung
1
, Scott D. Pletcher
1
. 1) Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI; 2) Huffington Center on Aging, Baylor
College of Medicine, Houston, TX.
Olfaction is an ancient sensory system present in many species from bacteria to humans. Exposure to nutrient-derived odorants can regulate aging and
longevity. In the absence of the broadly expressed atypical Odorant Receptor 83b (Or83b), conventional odorant receptors (ORs) are rendered in the cell
body and olfaction is compromised. Anosmic Or83b homozygous null flies are long-lived and they present enhanced stress resistance as well as increased fat
storage. Because Or83b is required for proper localization of conventional ORs to dendritic membranes, which is imperative for their function, we
hypothesize that the longevity phenotype and related physiological phenotypes seen in Or83b null flies are due to the loss of function of one or a subset of
conventional ORs. To dissect the specific effects of individual ORs, we assayed lifespan, metabolism, and stress resistance in a range of mutant lines in
which one to three ORs were deleted. Our results indicate that absence of one or a small number of conventional ORs can affect longevity and that they often
act in different manners. Flies that do not have a functional OR implicated in 11-
cis
-vaccenyl acetate-induced mating behavior, for example, are long-lived.
However, they have lower resistance to starvation compared to controls. On the contrary, certain receptor deletions result in a reduced lifespan while several
other ORs have little to no effect on longevity. This establishes that some individual ORs promote longevity while others limit it. Together our data suggest
that sensory systems rival the insulin-signaling, TOR, and translation-related pathways in the sheer number of effective manipulations that share a similar
function and induce potent and reproducible effects on organism lifespan.
735C
Spargel
, a mammalian PGC-1 homologue is involved in nutrient sensing pathway acting downstream to TOR and S6k.
Subhas Mukherjee, Claudette
Davis, Atanu Duttaroy. Biology Department, Howard University, Washington, DC.
Peroxysome proliferator-activated receptor gamma coactivator-1 (PGC-1) is a transcriptional coactivator in mammals. Among the two PGC-1 isotype,
PGC-1α is a master regulator of mitochondrial activities including gluconeogenesis, fatty acid oxidation, regulation of thermal tolerance, skeletal muscle
fibre determination and initiation of mitochondrial biogenesis. PGC-1β on the other hand is well known for fat synthesis. The single
PGC-1
gene of
Drosophila called spargel carries significant homology to both α and β forms at the RNA Recognition Motif. Spargel is a nutrient sensor since it gets
upregulated following the addition of nutrients after starvation. A recent study and our results confirmed that spargel is part of the insulin- signaling