Guy Bloch

Guy Bloch
Hebrew University of Jerusalem | HUJI · Department of Ecology, Evolution and Behavior

PhD
We have openings for both graduate students and postdocs. Please contact Guy for more information.

About

145
Publications
36,649
Reads
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Introduction
The main research interests of our group (http://guybloch.huji.ac.il/) are the evolution and mechanisms underlying sociality and social behavior, we study bees as a model. To study these fascinating and intricate phenomena we integrate analyses at different levels, from molecular to social. In recent years, one of our main research focuses has been the interplay between circadian rhythms and social behavior ("sociochronobiology").
Additional affiliations
June 2013 - present
Hebrew University of Jerusalem
Position
  • Professor (Full)
September 2009 - July 2015
Hebrew University of Jerusalem
Position
  • Head of Department
July 2007 - May 2013
Hebrew University of Jerusalem
Position
  • Professor (Associate)
Education
October 1992 - July 1997
Tel Aviv University
Field of study
  • Zoology

Publications

Publications (145)
Article
Full-text available
Honey bees live in colonies containing tens of thousands of workers that coordinate their activities to produce efficient colony-level behavior. In free-foraging colonies, nest bees are entrained to the forager daily phase of activity even when experiencing conflicting light-dark illumination regime, but little is known on the cues mediating this p...
Article
Full-text available
Background The developmental fates of offspring have the potential to be influenced by the identity of their care-givers and by the nature of the care that they receive. In animals that exhibit both parental and alloparental care, such as the annually eusocial insects, the influence of care-giver identity can be directly assessed to yield mechanist...
Article
Full-text available
Dominance hierarchies are ubiquitous in invertebrates and vertebrates, but little is known on how genes influence dominance rank. Our gaps in knowledge are specifically significant concerning female hierarchies, particularly in insects. To start filling these gaps, we studied the social bumble bee Bombus terrestris, in which social hierarchies amon...
Preprint
Full-text available
Dominance hierarchies are ubiquitous in invertebrates and vertebrates, but little is known on how genes influence dominance rank. Our gaps in knowledge are specifically significant concerning female hierarchies and in insects. To start filling these gaps we studied the social bumble bee Bombus terrestris, in which social hierarchies among females a...
Article
Full-text available
Many animals benefit from synchronizing their daily activities with conspe- cifics. In this hybrid paper, we first review recent literature supporting and extending earlier evidence for a lack of clear relationship between the level of sociality and social entrainment of circadian rhythms. Social entrainment is specifically potent in social animal...
Article
Full-text available
Specialisation and plasticity are important for many forms of collective behaviour, but the interplay between these factors is little understood. In insect societies, workers are often developmentally primed to specialise in different tasks, sometimes with morphological or physiological adaptations, facilitating a division of labour. Workers may al...
Article
Full-text available
Gonadotropic hormones coordinate processes in diverse tissues regulating animal reproductive physiology and behavior. Juvenile hormone (JH) is the ancient and most common gonadotropin in insects, but not in advanced eusocial honey bees and some ants. To start probing the evolutionary basis of this change, we combined endocrine manipulations, transc...
Article
Full-text available
The circadian and endocrine systems influence many physiological processes in animals, but little is known on the ways they interact in insects. We tested the hypothesis that juvenile hormone (JH) influences circadian rhythms in the social bumble bee Bombus terrestris. JH is the major gonadotropin in this species coordinating processes such as vite...
Article
Full-text available
The rapid increase in “big data” of the post-genomic era makes it crucial to appropriately measure the level of social complexity in comparative studies. We argue that commonly-used qualitative classifications lump together species showing a broad range of social complexity, and falsely imply that social evolution always progresses along a single l...
Article
Full-text available
Evolutionary transitions to a social lifestyle in insects are associated with lineage-specific changes in gene expression, but the key nodes that drive these regulatory changes are unknown. We examined the relationship between social organization and lineage-specific microRNAs (miRNAs). Genome scans across 12 bee species showed that miRNA copy-numb...
Preprint
Full-text available
The circadian and endocrine systems influence many physiological processes in animals, but little is known on the ways they interact in insects. We tested the hypothesis that juvenile hormone (JH) influences circadian rhythms in the social bumble bee Bombus terrestris. JH is the major gonadotropin in this species coordinating processes such as vite...
Preprint
Specialization and plasticity are important for many forms of collective behavior, but the interplay between these factors is little understood. In insect societies, workers are often predisposed to specialize in different tasks, sometimes with morphological or physiological adaptations, facilitating a division of labor. Workers may also plasticall...
Preprint
Full-text available
Gonadotropic hormones coordinate processes in diverse tissues regulating animal reproductive physiology and behavior. Juvenile hormone (JH) is the ancient and most common gonadotropin in insects, but not in advanced eusocial honey bees and ants. To probe the evolutionary basis of this change, we combined endocrine manipulations, transcriptomics, an...
Article
Full-text available
We studied phototaxis, the directional movement relative to light, in the bumble bee Bombus terrestris. We first developed and validated a MATLAB-based system enabling reliable high-resolution tracking of a bee and a measurement of her distance relative to a changing LED light source. Using this system, we found in all our experiments that workers...
Article
Full-text available
Circadian rhythms of about a day are ubiquitous in animals and considered functionally significant. Honey bees show remarkable circadian plasticity that is related to the complex social organization of their societies. Forager bees show robust circadian rhythms that support time-compensated sun-compass navigation, dance communication and timing vis...
Preprint
Full-text available
Abstract Internal circadian clocks organize animal behavior and physiology and are entrained by ecologically relevant external time-givers such as light and temperature cycles. In the highly social honey bee, social time-givers are potent and can override photic entrainment, but the cues mediating social entrainment are unknown. Here, we tested whe...
Article
Full-text available
Juvenile hormone (JH) is a key regulator of insect development and reproduction. Given that JH commonly affects adult insect fertility, it has been hypothesized to also regulate behaviors such as dominance and aggression that are associated with reproduction. We tested this hypothesis in the bumblebee Bombus terrestris for which JH has been shown t...
Article
Sleep is ubiquitous in vertebrates and invertebrates, and its loss is typically associated with reduced performance, health, or survival, for reasons that are yet unclear [1, 2, 3]. Nevertheless, some animals can reduce sleep for increasing foraging time [4], under predation risk [5, 6, 7, 8], during seasonal migration [9, 10, 11], or for having gr...
Preprint
Full-text available
Evolutionary transitions to a social lifestyle in insects are associated with lineage-specific changes in gene expression, but the key nodes that drive these regulatory changes are largely unknown. We tested the hypothesis that changes in gene regulatory function associated with social evolution are facilitated by lineage-specific microRNA (miRNA)...
Article
Size polymorphism is common in bees, and is determined by environmental factors such as temperature, brood cell size, and the diet provided to developing larvae. In social bees, these factors are further influenced by intricate interactions between the queen, workers, and the developing brood which eventually determine the final size and caste of d...
Preprint
Full-text available
We studied phtototaxis, the directional movement relative to light in the bumblebee Bombus terrestris. We first developed and validated a MATLAB based system enabling reliable high-resolution tracking of a bumblebee relative to a changing LED light source. Our tracking protocol enables us to separate the phototaxis response from simple directional...
Article
Full-text available
Colonies of the bumblebee Bombus terrestris are characterized by wide phenotypic variability among genetically similar full-sister workers, suggesting a major role for epigenetic processes. Here, we report a high level of ADAR-mediated RNA editing in the bumblebee, despite the lack of an ADAR1-homologue. We identify 1.15 million unique genomic site...
Preprint
Full-text available
Sleep is ubiquitous in vertebrates and invertebrates, and its chronic lost is typically associated with reduced performance, health, or survival. Nevertheless, some animals can give up sleep in order to increase survival or mating opportunities. We studied the interplay between sleep and brood care in the social bumblebee Bombus terrestris. We firs...
Article
Full-text available
Extracting complex interactions (i.e., dynamic topologies) has been an essential, but difficult, step toward understanding large, complex, and diverse systems including biological, financial, and electrical networks. However, reliable and efficient methods for the recovery or estimation of network topology remain a challenge due to the tremendous s...
Article
Several related and complementary theoretical frameworks have been proposed to explain the existence of prosocial behavior, despite its potential fitness cost to the individual. These include kin selection theory, proposing that organisms have a propensity to help those to whom they are genetically related, and reciprocity, referring to the benefit...
Article
Full-text available
Dynamic group coordination facilitates adaptive division of labor in response to group-level changes. Yet, little is known about how it can be operationalized in online collaborations among individuals with limited information about each other. We hypothesized that simple social information about the task distribution of others can elicit emergent...
Article
Full-text available
Pigment-Dispersing Factor (PDF) is an important neuropeptide in the brain circadian network of Drosophila and other insects, but its role in bees in which the circadian clock influences complex behaviour is not well understood. We combined high-resolution neuroanatomical characterizations, quantification of PDF levels over the day and brain injecti...
Article
Full-text available
Most processes within organisms, and most interactions between organisms and their environment, have distinct time profiles. The temporal coordination of such processes is crucial across levels of biological organization, but disciplines differ widely in their approaches to study timing. Such differences are accentuated between ecologists, who are...
Article
Full-text available
The interactions between flowering plants and insect pollinators shape ecological communities and provide one of the best examples of coevolution. Although these interactions have received much attention in both ecology and evolution, their temporal aspects are little explored. Here we review studies on the circadian organization of pollination-rel...
Article
Full-text available
The insect antennae receive olfactory information from the environment. In some insects, it has been shown that antennal responsiveness is dynamically regulated by circadian clocks. However, it is unknown how general this phenomenon is and what functions it serves. Circadian regulation in honeybee workers is particularly interesting in this regard...
Article
Full-text available
"Nurse" honeybees tend brood around-the-clock with attenuated or no circadian rhythms, but the brood signals inducing this behavior remain elusive. We first tested the hypothesis that worker circadian rhythms are regulated by brood pheromones. We monitored locomotor activity of individually isolated nurse bees that were either exposed to various do...
Article
Full-text available
Internal clocks driving rhythms of about a day (circadian) are ubiquitous in animals, allowing them to anticipate environmental changes. Genetic or environmental disturbances to circadian clocks or the rhythms they produce are commonly associated with illness, compromised performance or reduced survival. Nevertheless, some animals including Arctic...
Chapter
Insect societies are defined by an intricate division of labor among individuals. There is a reproductive division of labor between queens and workers, and a division of labor among workers for all activities related to colony growth and development. The different castes in an insect society and the diverse roles they play are extreme manifestation...
Article
A hallmark of insect societies is a division of labor among workers specializing in different tasks. In bumblebees the division of labor is related to body size; relatively small workers are more likely to stay inside the nest and tend (“nurse”) brood, whereas their larger sisters are more likely to forage. Despite their ecological and economic imp...
Article
Full-text available
Circadian rhythms in behaviour and physiology are important for animal health and survival. Studies with individually isolated animals in the laboratory have consistently emphasized the dominant role of light for the entrainment of circadian rhythms to relevant environmental cycles. Although in nature interactions with conspecifics are functionally...
Data
Supplementary Figures 1-6 and Supplementary Tables 1-11
Article
Full-text available
The emergence of eusociality (“true sociality”) in several insect lineages represents one of the most successful evolutionary adaptations in the animal kingdom in terms of species richness and global biomass. In contrast to solitary insects, eusocial insects evolved a set of unique behavioral and physiological traits such as reproductive division o...
Article
Full-text available
The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some spe...
Article
Full-text available
One of the most important and evolutionarily conserved roles of sleep is the processing and consolidation of information acquired during wakefulness. In both insects and mammals, environmental and social stimuli can modify sleep physiology and behavior, yet relatively little is known about the specifics of the wake experiences and their relative co...
Article
Full-text available
The evolution of advanced sociality in bees is associated with apparent modifications in juvenile hormone (JH) signaling. By contrast to most insects in which JH is a gonadotropin regulating female fertility, in the highly eusocial honey bee (Apis mellifera) JH has lost its gonadotrophic function in adult females, and instead regulates age-related...