scholarly journals Krüppel-Homologue 1 Mediates Hormonally-Regulated Dominance Rank in a Social Insect

2021 ◽  
Author(s):  
Atul Pandey ◽  
Guy Bloch
Keyword(s):  
Social Insect ◽  
Bombus Terrestris ◽  
Dominance Rank ◽  
Bumble Bee ◽  
Dominance Behavior ◽  
Social Hierarchies ◽  
Dominance Hierarchies ◽  
Multiple Factors ◽  
The Social ◽  
Wax Production

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 are common and functionally significant. Dominance rank in this bee is influenced by multiple factors, including juvenile hormone (JH) that is a major gonadotropin in this species. We tested the hypothesis that the JH responsive transcription factor Krüppel homologue 1 (Kr-h1) mediates hormonal influence on dominance behavior in the bumble bee. We first developed and validated a perfluorocarbon nanoparticles-based RNA interference protocol for knocking down Kr-h1 expression. We then used this procedure to show that Kr-h1 mediates the influence of JH not only on oogenesis and wax production, but also on aggression and dominance rank. To the best of our knowledge, this is the first study causally linking a gene to dominance rank in social insects, and one of only a few such studies in insects or in female hierarchies. These findings are important for determining whether there are general molecular principles governing dominance rank across gender and taxa.

scholarly journals Krüppel-homologue 1 Mediates Hormonally Regulated Dominance Rank in a Social Bee

Biology ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1188
Author(s):  
Atul Pandey ◽  
Guy Bloch
Keyword(s):  
Bombus Terrestris ◽  
Dominance Rank ◽  
Bumble Bee ◽  
Dominance Behavior ◽  
Social Hierarchies ◽  
Dominance Hierarchies ◽  
Multiple Factors ◽  
The Social ◽  
Wax Production ◽  
Social Bee

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 among females are common and functionally significant. Dominance rank in this bee is influenced by multiple factors, including juvenile hormone (JH) that is a major gonadotropin in this species. We tested the hypothesis that the JH responsive transcription factor Krüppel homologue 1 (Kr-h1) mediates hormonal influences on dominance behavior. We first developed and validated a perfluorocarbon nanoparticles-based RNA interference protocol for knocking down Kr-h1 expression. We then used this procedure to show that Kr-h1 mediates the influence of JH, not only on oogenesis and wax production, but also on aggression and dominance rank. To the best of our knowledge, this is the first study causally linking a gene to dominance rank in social insects, and one of only a few such studies on insects or on female hierarchies. These findings are important for determining whether there are general molecular principles governing dominance rank across gender and taxa.

scholarly journals Juvenile hormone affects the development and strength of circadian rhythms in young bumble bee (Bombus terrestris) workers

2020 ◽  
Author(s):  
Atul Pandey ◽  
Uzi Motro ◽  
Guy Bloch
Keyword(s):  
Circadian Rhythms ◽  
Juvenile Hormone ◽  
Bombus Terrestris ◽  
Bumble Bee ◽  
Early Age ◽  
Ovarian Activity ◽  
Physiological Processes ◽  
The Social ◽  
Free Running ◽  
Wax Production

AbstractThe 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 vitellogenesis, oogenesis, wax production, and behaviors associated with reproduction. It is unknown however, whether it also influences circadian processes. We topically treated newly-emerged bees with the allatoxin Precocene-I (P-I) to reduce circulating JH titers and applied the natural JH (JH-III) for replacement therapy. We repeated this experiment in three trials, each with bees from different source colonies. Measurements of ovarian activity confirmed that our JH manipulations were effective; bees treated with P-I had inactive ovaries, and this effect was fully reverted by subsequent JH treatment. We found that JH augments the strength of circadian rhythms and the pace of rhythm development in individually isolated newly emerged worker bees. JH manipulation did not affect the free-running circadian period, overall level of locomotor activity, or the amount of sleep. Given that acute manipulation at an early age produced relatively long-lasting effects, we propose that JH effect on circadian rhythms is mostly organizational, accelerating the development or integration of the circadian system.

scholarly journals Juvenile hormone interacts with multiple factors to modulate aggression and dominance in groups of orphan bumble bee (Bombus terrestris) workers

2019 ◽  
Author(s):  
Atul Pandey ◽  
Uzi Motro ◽  
Guy Bloch
Keyword(s):  
Body Size ◽  
Juvenile Hormone ◽  
Replacement Therapy ◽  
Dominance Hierarchy ◽  
Bombus Terrestris ◽  
Dominance Rank ◽  
Bumble Bees ◽  
Bumble Bee ◽  
Multiple Factors ◽  
Similar Body

AbstractJuvenile 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 bumble bee Bombus terrestris for which JH has been shown to be the major gonadotropin. We used the allatoxin Precocene-I (P-I) to reduce hemolymph JH titers and replacement therapy with the natural JH to revert this effect. In small orphan groups of workers with similar body size but mixed treatment, P-I treated bees showed lower aggressiveness, oogenesis, and dominance rank compared with control and replacement therapy treated bees. In similar groups in which all bees were treated similarly, there was a clear dominance hierarchy, even in P-I and replacement therapy treatment groups in which the bees showed similar levels of ovarian activation. In a similar experiment in which bees differed in body size, larger bees were more likely to be dominant despite their similar JH treatment and ovarian state. In the last experiment, we show that JH manipulation does not affect dominance rank in groups that had already established a stable dominance hierarchy. These findings solve previous ambiguities concerning whether or not JH affects dominance in bumble bees. JH positively affects dominance, but bees with similar levels of JH can nevertheless establish dominance hierarchies. Thus, multiple factors including JH, body size, and previous experience affect dominance and aggression in social bumble bees.

scholarly journals Methylation and worker reproduction in the bumble-bee ( Bombus terrestris )

2014 ◽  
Vol 281 (1780) ◽  
pp. 20132502 ◽  
Author(s):  
Harindra E. Amarasinghe ◽  
Crisenthiya I. Clayton ◽  
Eamonn B. Mallon
Keyword(s):  
Genomic Imprinting ◽  
Social Insects ◽  
Social Insect ◽  
Bombus Terrestris ◽  
Division Of Labour ◽  
Worker Reproduction ◽  
Bumble Bee ◽  
Reproductive Division Of Labour ◽  
Reproductive Division

Insects are at the dawn of an epigenetics era. Numerous social insect species have been found to possess a functioning methylation system, previously not thought to exist in insects. Methylation, an epigenetic tag, may be vital for the sociality and division of labour for which social insects are renowned. In the bumble-bee Bombus terrestris , we found methylation differences between the genomes of queenless reproductive workers and queenless non-reproductive workers. In a follow up experiment, queenless workers whose genomes had experimentally altered methylation were more aggressive and more likely to develop ovaries compared with control queenless workers. This shows methylation is important in this highly plastic reproductive division of labour. Methylation is an epigenetic tag for genomic imprinting (GI). It is intriguing that the main theory to explain the evolution of GI predicts that GI should be important in this worker reproduction behaviour.

scholarly journals Olfactory coding in the antennal lobe of the bumble bee Bombus terrestris

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marcel Mertes ◽  
Julie Carcaud ◽  
Jean-Christophe Sandoz
Keyword(s):  
Honey Bees ◽  
Antennal Lobe ◽  
Bombus Terrestris ◽  
Bumble Bees ◽  
Foraging Strategies ◽  
Bumble Bee ◽  
Carbon Chain Length ◽  
Olfactory Coding ◽  
Major Transitions

AbstractSociality is classified as one of the major transitions in evolution, with the largest number of eusocial species found in the insect order Hymenoptera, including the Apini (honey bees) and the Bombini (bumble bees). Bumble bees and honey bees not only differ in their social organization and foraging strategies, but comparative analyses of their genomes demonstrated that bumble bees have a slightly less diverse family of olfactory receptors than honey bees, suggesting that their olfactory abilities have adapted to different social and/or ecological conditions. However, unfortunately, no precise comparison of olfactory coding has been performed so far between honey bees and bumble bees, and little is known about the rules underlying olfactory coding in the bumble bee brain. In this study, we used in vivo calcium imaging to study olfactory coding of a panel of floral odorants in the antennal lobe of the bumble bee Bombus terrestris. Our results show that odorants induce reproducible neuronal activity in the bumble bee antennal lobe. Each odorant evokes a different glomerular activity pattern revealing this molecule’s chemical structure, i.e. its carbon chain length and functional group. In addition, pairwise similarity among odor representations are conserved in bumble bees and honey bees. This study thus suggests that bumble bees, like honey bees, are equipped to respond to odorants according to their chemical features.

scholarly journals Social environment influences the relationship between genotype and gene expression in wild baboons

2013 ◽  
Vol 368 (1618) ◽  
pp. 20120345 ◽  
Author(s):  
Daniel E. Runcie ◽  
Ralph T. Wiedmann ◽  
Elizabeth A. Archie ◽  
Jeanne Altmann ◽  
Gregory A. Wray ◽  
...  
Keyword(s):  
Gene Expression ◽  
Individual Differences ◽  
Social Environment ◽  
Group Size ◽  
Early Life ◽  
Social Connectedness ◽  
Dominance Rank ◽  
Social Stressors ◽  
The Social ◽  
Wild Baboons

Variation in the social environment can have profound effects on survival and reproduction in wild social mammals. However, we know little about the degree to which these effects are influenced by genetic differences among individuals, and conversely, the degree to which social environmental variation mediates genetic reaction norms. To better understand these relationships, we investigated the potential for dominance rank, social connectedness and group size to modify the effects of genetic variation on gene expression in the wild baboons of the Amboseli basin. We found evidence for a number of gene–environment interactions (GEIs) associated with variation in the social environment, encompassing social environments experienced in adulthood as well as persistent effects of early life social environment. Social connectedness, maternal dominance rank and group size all interacted with genotype to influence gene expression in at least one sex, and either in early life or in adulthood. These results suggest that social and behavioural variation, akin to other factors such as age and sex, can impact the genotype–phenotype relationship. We conclude that GEIs mediated by the social environment are important in the evolution and maintenance of individual differences in wild social mammals, including individual differences in responses to social stressors.

Sign in / Sign up

Export Citation Format

Share Document