Tissue remodeling: a mating-induced differentiation program for the Drosophila oviduct

<p>Abstract</p> <p>Background</p> <p>In both vertebrates and invertebrates, the oviduct is an epithelial tube surrounded by visceral muscles that serves as a conduit for gamete transport between the ovary and uterus. While <it>Drosophila </it>is a model system for tubular organ development, few studies have addressed the development of the fly's oviduct. Recent studies in <it>Drosophila </it>have identified mating-responsive genes and proteins whose levels in the oviduct are altered by mating. Since many of these molecules (e.g. Muscle LIM protein 84B, Coracle, Neuroglian) have known roles in the differentiation of muscle and epithelia of other organs, mating may trigger similar differentiation events in the oviduct. This led us to hypothesize that mating mediates the last stages of oviduct differentiation in which organ-specific specializations arise.</p> <p>Results</p> <p>Using electron- and confocal-microscopy we identified tissue-wide post-mating changes in the oviduct including differentiation of cellular junctions, remodeling of extracellular matrix, increased myofibril formation, and increased innervation. Analysis of once- and twice-mated females reveals that some mating-responsive proteins respond only to the first mating, while others respond to both matings.</p> <p>Conclusion</p> <p>We uncovered ultrastructural changes in the mated oviduct that are consistent with the roles that mating-responsive proteins play in muscle and epithelial differentiation elsewhere. This suggests that mating triggers the late differentiation of the oviduct. Furthermore, we suggest that mating-responsive proteins that respond only to the first mating are involved in the final maturation of the oviduct while proteins that remain responsive to later matings are also involved in maintenance and ongoing function of the oviduct. Taken together, our results establish the oviduct as an attractive system to address mechanisms that regulate the late stages of differentiation and maintenance of a tubular organ.</p

Seismic signals are crucial for male mating success in a visual specialist jumping spider (Araneae: Salticidae)

The diversity of courtship displays throughout the animal kingdom is immense and displays can range from seemingly simple, to incredibly complex. Signalers often possess elaborate morphological adaptations for signals directed at a specific sensory modality in receivers. In some cases, these signals are so compelling to human observers, the possibility that important signals exist in other sensory modalities is ignored, potentially resulting in an incomplete characterization of the communication system. Jumping spiders (Salticidae) have remarkable visual capabilities. Yet one species, Habronattus dossenus, has recently been shown to have a complex repertoire of multicomponent seismic courtship signals in addition to and produced in concert with its multiple visual ornaments and movement displays. Here, we demonstrate the importance of these seismic signals in the courtship display of H. dossenus by comparing mating frequencies across experimentally manipulated treatments. Virgin females were paired with males from one of two experimental groups: nonmuted males or muted males. We found that females were significantly more likely to copulate with nonmuted males than with muted males. Furthermore, in all pairs that copulated, the latency to copulation was significantly shorter in nonmuted pairings than in muted pairings and precopulatory cannibalism rates were significantly lower. These results demonstrate that seismic signals are a critical component of male H. dossenus courtship displays. Additionally, we demonstrate that many other Habronattus species include a diversity of seismic signals in their courtship displays and we discuss potential selection pressures that may drive the evolution of multimodal displays even in species that already possess elaborate morphological adaptations for signals directed at one sensory modality

Ogre-Faced, Net-Casting Spiders Use Auditory Cues to Detect Airborne Prey

Prey-capture behavior among spiders varies greatly from passive entrapment in webs to running down prey items on foot. Somewhere in the middle are the ogre-faced, net-casting spiders (Deinopidae: Deinopis) that actively capture prey while being suspended within a frame web. Using a net held between their front four legs, these spiders lunge downward to ensnare prey from off the ground beneath them. This “forward strike” is sensorially mediated by a massive pair of hypersensitive, night-vision eyes. Deinopids can also intercept flying insects with a “backward strike,” a ballistically rapid, overhead back-twist, that seems not to rely on visual cues. Past reports have hypothesized a role of acoustic detection in backward strike behavior. Here, we report that the net-casting spider, Deinopis spinosa, can detect auditory stimuli from at least 2 m from the sound source, at or above 60 dB SPL, and that this acoustic sensitivity is sufficient to trigger backward strike behavior. We present neurophysiological recordings in response to acoustic stimulation, both from sound-sensitive areas in the brain and isolated forelegs, which demonstrate a broad range of auditory sensitivity (100–10,000 Hz). Moreover, we conducted behavioral assays of acoustic stimulation that confirm acoustic triggering of backward net-casting by frequencies in harmony with flight tones of known prey. However, acoustic stimulation using higher frequency sounds did not elicit predatory responses in D. spinosa. We hypothesize higher frequencies are emitted by avian predators and that detecting these auditory cues may aid in antipredator behavior

Ohio Economic Insects and Related Anthropods

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Globalization and Health: developing the journal to advance the field

Founded in 2005, Globalization and Health was the first open access global health journal. The journal has since expanded the field, and its influence, with the number of downloaded papers rising 17-fold, to over 4 million. Its ground-breaking papers, leading authors -including a Nobel Prize winner- and an impact factor of 2.25 place it among the top global health journals in the world. To mark the ten years since the journal’s founding, we, members of the current editorial board, undertook a review of the journal’s progress over the last decade. Through the application of an inductive thematic analysis, we systematically identified themes of research published in the journal from 2005 to 2014. We identify key areas the journal has promoted and consider these in the context of an existing framework, identify current gaps in global health research and highlight areas we, as a journal, would like to see strengthened

Female preference for complex/novel signals in a spider

Identifying the various factors that influence complex signal evolution is a difficult task, yet it is fundamental to understanding the evolution of animal communication. Here we explore the evolution of complex courtship signaling by taking advantage of a system in which sexual selection on male courtship traits has driven the diversification of geographically isolated populations of the jumping spider Habronattus pugillis Griswold. Using 2 populations (Santa Rita [SR] and Atascosa [AT]) in which SR females show xenophilic mating preferences for foreign (AT) over local males (SR), we examine the mechanisms driving this preference. Both AT and SR males produce multimodal signals (visual + seismic), and while SR and AT signals share certain seismic components, AT seismic signals are more complex and contain novel components. We conducted mate choice trials where SR females were presented with AT or SR males that were either muted or nonmuted. SR females preferred to mate and mated more quickly with foreign AT males over local SR males only if AT males could produce seismic signals (nonmuted treatment). In addition, we found that SR females spent a higher proportion of time attentive to foreign AT males only if they could produce seismic signals. This evidence suggests that SR females have a bias for complex and/or novel forms of seismic signals

REGIONAL SEISMIC SONG DIFFERENCES IN SKY ISLAND POPULATIONS OF THE JUMPING SPIDER \u3ci\u3eHABRONATTUS PUGILLIS\u3c/i\u3e GRISWOLD (ARANEAE, SALTICIDAE)

Jumping spiders have long been used as model organisms to study visual communication. However, recent studies documenting the presence of intricate multicomponent seismic songs during courtship displays suggest an important role of seismic communication as well. Given the relatively recent focus on seismic communication, the extent to which seismic songs vary among jumping spider species or even among populations remains poorly understood. Here, we use the extensively studied Habronattus pugillis Griswold 1987 complex to explore putative seismic song diversity among males from isolated populations. H. pugillis populations have been studied extensively because of the tremendous diversification of male visual secondary sexual ornaments observed among adjacent mountain-top populations in southeastern Arizona (“sky islands”). Here, we aim to explore putative parallel patterns of diversification in seismic courtship songs between different sky island populations. Using laser vibrometry, we examined in detail the songs of three mountaintop populations (Atascosa (AT), Santa Rita (SR), and Santa Catalina (SC)) and observed an extraordinary diversity of songs and song types among these three populations. Large differences were seen in both the temporal and spectral properties of male seismic songs. In addition, we observed differences in song complexity between populations with some populations having “simple” songs (1 component) and others having “complex” songs (3 components). We also present preliminary data from four additional populations (Galiuro (GA), Huachuca (HU), Mule (MU), and Patagonia (PA)). Results from this study suggest that the diversification of male visual signals observed among populations of H. pugillis finds a counterpart in male seismic songs