Biology subjects

Ben-Shahar, Y.

Publications and source records attributed to Ben-Shahar, Y..

4 recordsLinked to original sources

bioRxiv2018

Chemical signatures of honey bee group membership develop via a socially-modulated innate process

Large social insect colonies exhibit a remarkable ability for recognizing group members via colony-specific cuticular hydrocarbon (CHC) pheromonal signatures. Previous work suggested that in some ant species colony-specific signatures are generated through a \"gestalt\" mechanism via the passive transfer and homogenization of CHCs across all individual members of the colony. In contrast, we demonstrate that nestmate recognition cues of worker honey bees (Apis mellifera) mature in foragers via a sequence of stereotypic age-dependent quantitative and qualitative chemical transitions, which are driven by intrinsic biosynthetic pathways. Therefore, in contrast to predictions of the \"Gestalt\" model, nestmate recognition cues in honey bee colonies do not represent a passive \"average\" signature that is carried and recognized by all colony members. Instead, specific colony members develop the relevant cues via an innately-determined developmental program that can be modulated by colony-specific social environmental factors.

animal behavior and cognition↗

bioRxiv2018

Natural selection on gene-specific codon usage bias is common across eukaryotes

Although the actual molecular evolutionary forces that shape differences in codon usage across species remain poorly understood, majority of synonymous mutations are assumed to be functionally neutral because they do not affect protein sequences. However, empirical studies suggest that some synonymous mutations can have phenotypic consequences. Here we show that in contrast to the current dogma, natural selection on gene-specific codon usage bias is common across Eukaryota. Furthermore, by using bioinformatic and experimental approaches, we demonstrate that specific combinations of rare codons contribute to the spatial and sex-related regulation of some protein-coding genes in Drosophila melanogaster. Together, these data indicate that natural selection can shape gene-specific codon usage bias, which therefore, represents an overlooked genomic feature that is likely to play an important role in the spatial and temporal regulation of gene functions. Hence, the broadly accepted dogma that synonymous mutations are in general functionally neutral should be reconsidered.

evolutionary biology↗

bioRxiv2017

Early warning signals regarding environmental suitability in the Drosophila antenna

HighlightsO_LIA novel geotaxis assay showed high intensity odorant exposures are harmful to flies\nC_LIO_LIRepulsion at high odor intensities can be a protective mechanism\nC_LIO_LIOlfactory receptor neuron (ORN) excitability abruptly changes with odor intensity\nC_LIO_LIA linear combination of ORN activities can robustly predict intensity-dependent behavioral repulsion\nC_LI\n\nSummaryThe olfactory system is uniquely positioned to warn an organism of environmental threats. Whether and how it encodes such information is not understood. Here, we examined this issue in the fruit fly Drosophila melanogaster. We found that intensity-dependent repulsion to chemicals safeguarded flies from harmful, high-intensity vapor exposures. To understand how sensory input changed as the odor valence switched from innocuous to threatening, we recorded from olfactory receptor neurons (ORNs) in the fly antenna. Primarily, we observed two response non-linearities: recruitment of non-active ORNs at higher intensities, and abrupt transitions in neural excitability from regular spiking to high-firing oscillatory regime. Although non-linearities observed in any single ORN was not a good indicator, a simple linear combination of firing events from multiple neurons provided robust recognition of threating/repulsive olfactory stimuli. In sum, our results reveal how information necessary to avoid environmental threats may also be encoded in the insect antenna.

neuroscience↗

bioRxiv2017

Pleiotropic Chemoreceptors Facilitate The Maintenance Of Signal-Receptor Coupling In Pheromonal Communication

Optimal mating decisions depend on stable signaling systems because any independent changes in either the signal or its perception could carry a fitness cost. However, since the perception and production of specific mating signals are often mediated by different tissues and cell types, the genetic and cellular mechanisms that drive and maintain their coupling on the evolutionary and physiological timescales remain unknown for most animal species. Here, we show that in Drosophila melanogaster, sensory perception and synthesis of an inhibitory mating pheromone is regulated by the action of Gr8a, a member of the Gustatory receptor gene family. Particularly, Gr8a acts as a pheromone chemoreceptor in the sensory system of males and females, and, independently regulates pheromone synthesis in the male fat body and oenocytes. These data provide a relatively simple molecular explanation for how genetic coupling allows for the robust and stable flow of social information at the population level.

genetics↗