Basic HTML Version
Poster Full Abstracts - Neurophysiology and Behavior
Poster board number is above title. The first author is the presenter
296
shown that IPI contributes to species recognition and con-specific mating. Our data shows that flightin N-terminal sequence has a stronger effect in song
production than in flight ability. We propose that flightin fulfills a dual function, enhancing flight power output for survival and influencing song parameters
important for pre-mating isolation, through separate protein domains that are under distinct evolutionary constraints. Positive or sexual selection acting on N-
terminal flightin sequences may explain its hypervariability.
616A
Drosophila
female precopulatory behavior is modulated by ecdysteroids.
Geoffrey Ganter
1
, Joseph Desilets
1
, Jessica Davis-Heim
1
, Alexandra Panaitiu
1
,
Mark Sweezy
2
, Joseph Sungail
1
, Leonard Tan
1
, Aurora Adams
1
, Elizabeth Fisher
1
, Joselle O'Brien
1
, Kelsey Kincaid
1
, Ralf Heinrich
3
. 1) Department of
Biology, College of Arts and Sciences, University of New England, Biddeford, Maine, 04005, USA; 2) Department of Pharmaceutical Sciences, School of
Pharmacy, Saint Joseph College, West Hartford, Connecticut, 06117, USA; 3) Department of Cellular Neurobiology, Institute for Zoology, Georg-August-
University, Göttingen, Germany.
The effect of ecdysteroid signaling on
Drosophila melanogaster
female precopulatory behavior was interrogated using two types of mutants. The first
featured reduced expression of ecdysone receptor in sex-specific fruitless neurons (Gal4-targeted RNAi allele). In the second, global ecdysteroid levels were
reduced after successful development to adulthood using the temperature-sensitive allele
ecdysoneless
1
. While being courted by wild-type males, both types
of mutant females performed significantly less full ovipositor extrusion behavior to reject male courtship progression. Wild-type levels of rejection behavior
were partly restored in
ecdysoneless
1
females by feeding of 20-hydroxyecdysone. In addition, ecdysteroid depleted females (
ecdysoneless
1
) performed male-
like courtship behaviors, including unilateral wing extension and song production with patterns very similar to male courtship song. Since ecdysteroid levels
provided by this temperature sensitive allele were sufficient for successful larval and pupal development and were experimentally manipulated only after the
females reached adulthood, the altered behavior observed may indicate acute effects of steroid level on an otherwise normal nervous system. These results
support the hypothesis that ecdysteroids modulate female sexual behavior, perhaps acting as a regulator of sexual motivation, and as a component affecting
the selection of sex specific behavior patterns.
617B
The seminal protein, ovulin, increases ovulation behavior through signaling of OA neurons.
Clifford D. Rubinstein, Mariana F. Wolfner. Department of
Molecular Biology & Genetics, Cornell University, Ithaca, NY.
Broad behavioral changes are triggered in
Drosophila
females upon mating, and seminal proteins are important induces of these changes this process.
However, little is understood about how these male proteins interact with female physiology to influence female behavior. The seminal fluid protein ovulin
increases ovulation rates during the first 24 hours after mating. We tested whether it does so through neural signaling systems. Since the neuromodulator
octopamine (OA) is known to regulate
Drosophila
ovulation, we hypothesized that ovulin may work through OA neuronal signaling. We found that
increased OA neuronal activity in females could rescue the ovulation decrease normally observed in mates of ovulin null males, suggesting ovulin acts
upstream of OA neuronal signaling. Consistent with ovulin acting through OA neurons, we found that the mating-dependant decrease in basal contraction
state of oviduct muscle requires ovulin. Presumably, this relaxes the oviduct to facilitate movement of an egg from the ovary to the oviduct. Our results
suggest that ovulin acts to increase OA signaling at the oviduct neuromuscular junction (NMJ). Kapelnikov et al. (2008
BMC Dev Biol
) previously reported
a mating-dependent increase in bouton number at the oviduct NMJ, a morphological measurement of synaptic strength. We are testing whether this synaptic
response to mating is due to ovulin action. Together, our results suggest that ovulin acts as a neuromodulator between the male and the female to either
increase OA neuronal activity or increase OA signaling at the oviduct NMJ.
618C
Behavioral Plasticity of Drosophila melanogaster in response to varying social experiences.
Sehresh Saleem, Ginger Carney. Texas A&M University,
College Station, TX.
Behaviors are multifaceted phenotypes mediated by a complex integration of genotypic and environmental information. Phenotypic plasticity is vital for
increasing fitness of animals in the face of rapidly changing environments. We curretly have a poor understanding of how the environment affects gene
expression to bring about these behavioral responses. We investigated
Drosophila melanogaster
reproductive behaviors to evaluate these complex
interaction networks. Reproductive behaviors in
Drosophila melanogaster
are regulated by a tightly orchestrated set of genes and further modified by
diverse environments. In order to determine environmental influence on these behaviors, we quantified the environmental influence on male copulation
duration and female re-mating latency. We show that virgin, wild-type males aged in groups with other males modify their behavior towards females.
Grouped males copulated with females for a significantly longer time compared to males raised in isolation. We found that female re-mating latency was
affected by copulation duration. Females that experienced long initial copulations had longer latencies to re-mating. Therefore, longer mating duration may
lead to increased offspring production by the first male. Together, these results suggest that males perceive high sperm competition when reared with in
groups and modify their reproductive behaviors in order to increase their chances of siring more offspring. In order to identify the genes mediating these
plastic responses in
Drosophila
, we evaluated candidate genes that are differentially expressed in the male head when males interact for 20 minutes (Ellis
and Carney 2010). We tested the effects of mutations in these genes on copulation duration under environments where perceived sperm competition is high.
Identification of genes which mediate phenotypic plasticity under varying environmental pressures, such as competition for mates, will be the first step
towards delineating these complex genotype-to-phenotype maps.
619A
Investigating the role of a fourth chromosome mutation in courtship receptivity and decisionmaking.
Joseph Schinaman, Rui Sousa-Neves.
Department of Biology, Case Western Reserve University, Cleveland, OH.
In nature, during the process of mate selection, females often have to recognize males of their own species and select amongst them the individuals with
the most effective courtship display. This process of decision-making relies on a multi-modal stimulation and results in either acceptance or rejection of the
courting male.
dati
1
is a recessive mutation which causes females to be unresponsive to male courtship and respond actively with rejection.
dati
1
encodes a
transcription factor located on the Drosophila 4
th
chromosome and its phenotype can be fully reverted by the excision of the P-element that causes the