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Poster Full Abstracts - Physiology and Aging
Poster board number is above title. The first author is the presenter
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pathway. More over, the smaller body size, reduced ATP, protein and fat content of spargel hypomorph,
srl
1
suggests that spargel is required for nutrients
utilization. Therefore, our objective is to place spargel in the insulin-signaling pathway appropriately in relation to other partners in the pathway. Since over
expression of spargel in the fat body increases the production of fat and ATP this data indicates that spargel facilitates better utilization of nutrients which is
also a hallmark function of TOR (Target of Rapamycin) and S6 kinase. Both TOR and S6K are integral parts of a highly conserved metabolic pathway
starting from yeast to Human. Therefore, down regulation of TOR and S6K reduces the viability in flies. Absence of S6k reduces the cell size severely. We
found that
spargel
over expression successfully rescues the S6k dominant negative mutant. Absence of TOR causes premature death in Drosophila around
2nd instar larval stage, but Spargel over expression effectively rescued this TOR dominant negative phenotype by helping the mutants to live up to the pupal
stage and some adult eclosion was also evident. This data strongly suggests that spargel controls cell growth and metabolism by acting downstream to
Tor/S6k in the nutrient utilization pathway.
736A
Impact of Supplementing Taurine in the diet of
Drosophila
.
Lee A. Smith
1
, Feras Alhourani
1
, Ishtiaq Habib
1
, Brian Talon
1
, Stephanie Shirkey
1
, Jeremy
Nadolski
2
. 1) Dept Biological Sci, Benedictine Univ, Lisle, IL; 2) Dept Mathematical and Computational Sci, Benedictine Univ, Lisle, IL.
As the amino acid taurine is being used more frequently in human diets, the exact physiological role and benefit have not been fully elucidated. To
determine if taurine can impact long term physiology, we investigated the effects of a chronic taurine supplemented diet on adult life span, egg-laying, and
larval development. A comparison of survival curves found a significant difference between male and female fruit flies supplemented with a taurine diet as
well as a difference between taurine and normal fed fruit flies with respect to gender. Current experiments are investigating if the benefit of taurine is due to
its anti-oxidant ability. The effect of taurine does not provide a benefit during early development of the fly, rather it reduces the number of hatched larvae in
a concentration-dependent manner. Given the sensitivity of eggs to taurine, we are testing whether females avoid laying eggs given a choice between normal
and taurine supplemented food.
737B
Genome wide association study for visual decline in a population of aging
Drosophila melanogaster
.
Mary A. Carbone
1,2
, Tess A. Brune
1
, Akihiko
Yamamoto
2,3
, Michael M. Magwire
1,2
, Trudy F.C. Mackay
1,2
, Robert R.H. Anholt
2,3
. 1) Department of Genetics, North Carolina State University, Raleigh,
NC; 2) W. M. Keck Center for Behavioral Biology, North Carolina State University, Raleigh, NC; 3) Department of Biology, North Carolina State
University, Raleigh, NC.
Age-related eye diseases affect more than 3 million Americans over the age of 40. Such disorders include cataracts, glaucoma and macular degeneration.
Genes that maintain phenotypic variation in vision disorders in natural populations are unknown. Here, we used a population of wild-derived
Drosophila
melanogaster
, known as the
Drosophila
Genome Reference Panel (DGRP), to characterize variation in visual acuity in aging flies, by assaying their
phototaxis behavior using a countercurrent apparatus. We performed a genome wide association study (GWAS) and identified polymorphisms (SNPs)
significantly associated with phototaxis in the genes
cacophony
and
rugose
. The gene
cacophony
is involved in the detection of light stimulus for visual
perception, while
rugose
functions in the differentiation of compound eye cone-cells. We demonstrate the use of
Drosophila melanogaster
as a model
system to decipher the genetic networks that modulate the natural variation in age-related decline in visual acuity.
738C
Cellular and Physiological Basis of Thermal Plasticity of Body and Organ Size in
Drosophila melanogaster
.
Shampa Ghosh Modak, Alexander W.
Shingleton. Zoology, Michigan State University, East Lansing, MI.
Body size and temperature show an inverse relationship in most organisms including
Drosophila
, a phenomenon commonly known as the ‘temperature
size rule’. In addition, different organs of the fly show different levels of thermal sensitivity during pre-adult growth. However, the developmental genetic
underpinning of thermal regulation of body and organ size in flies, or any organism, is almost completely unknown. Size in
Drosophila
is regulated by three
aspects of pre-adult development: (i) critical size; (ii) growth rate during the terminal growth period (TGP)
i. e.
the time between critical size and the
cessation of growth; and (iii) the duration of the TGP. Temperature presumably generates plasticity in body and organ size by affecting one or all of these
three parameters. Here we describe the extent to which changes in critical size, growth rate and TGP contribute to thermal plasticity in
D. melanogaster
.
Such data are an essential prelude for understanding how temperature influences the developmental genetic mechanisms that regulate each parameter and
hence body size as a whole. Further, we use clonal analysis to show that the thermal sensitivity of cell proliferation varies among organs. These data explain,
in part, why there is variation among organs in their size response to temperature.
739A
Life history Variation and Reproductive Senescence in Three Recently Caught Wild-type Populations of Drosophila melanogaster.
Peter Klepsatel,
Martina Galikova, Nicola de Maio, Christian Schlötterer, Thomas Flatt. Institute of Population Genetics, Vienna, Austria.
The life history of D. melanogaster is relatively well studied, but life history data are typically obtained by averaging over many individuals rather than
following single individuals over time. Moreover, most studies have examined life history traits in lab strains kept for a long time rather than working with
individuals freshly sampled from natural populations and may thus be confounded by effects of lab adaptation and inbreeding. Here we focus on variation in
life history traits (fecundity, ovariole number, hatchability, lifespan) measured on freshly collected individuals from three different wild-type populations of
D. melanogaster. We found significant variation among populations for all traits, in particular for different fecundity traits, and used these data to create a
mathematical model of individual fecundity and reproductive senescence. Fecundity data were best described by a model with four distinct phases during a
female’s life: onset of maturity, reproductive senescence, fecundity "collapse", and a postovipository period. Interestingly, the onset of the postovipository
period was a good predictor of death, with females dying 6-9 days after laying their last egg, irrespective how long they lived. We also examined phenotypic
correlations between traits. We failed to find negative correlations (trade-offs) between early and late fecundity or between different fecundity measures and
lifespan. Ovariole number was positively correlated with early daily fecundity in all populations, but uncorrelated with late or total fecundity. In general,
most fitness components were positively correlated. This preponderance of positive correlations is unlikely due to inbreeding or positive mutational
covariance but is probably best explained by optimal lab conditions. Fitness traits measured in the lab might thus reflect unconstrained physiological state