scholarly journals Vitellogenin expression in the ovaries of adult honeybee workers provides insights into the evolution of reproductive and social traits

2019 ◽  
Author(s):  
Carlos Antônio Mendes Cardoso-Júnior ◽  
Benjamin P. Oldroyd ◽  
Isobel Ronai
Keyword(s):  
Molecular Basis ◽  
Royal Jelly ◽  
Insulin Signalling ◽  
Queen Pheromone ◽  
Regulatory Proteins ◽  
Reproductive Capacity ◽  
Ovary Activation ◽  
Ground Plan ◽  
Social Traits ◽  
Honey Bee Workers

AbstractSocial insects are notable for having two female castes that exhibit extreme differences in their reproductive capacity. The molecular basis of these differences is largely unknown. A protein that likely plays a key role in these differences is Vitellogenin (Vg), a powerful antioxidant and insulin-signalling regulator. Here we investigate how Royal Jelly (the major food of honeybee queens) and queen pheromone (a major regulator of worker fertility), affects the longevity and reproductive status of honey bee workers, the expression of Vg, its receptor VgR and associated regulatory proteins. We find that Vg is expressed in the ovaries of workers and that workers fed a queen diet of Royal Jelly have increased Vg expression in the ovaries. Surprisingly, we find that Vg expression is not associated with worker ovary activation. Our findings provide further support for the ‘reproductive ground plan hypothesis’ as Vg has acquired non-reproductive functions in honeybee workers.

scholarly journals Irreversible sterility of workers and high-volume egg production by queens in the stingless bee Tetragonula carbonaria

2020 ◽  
Author(s):  
Francisco Garcia Bulle Bueno ◽  
Rosalyn Gloag ◽  
Tanya Latty ◽  
Isobel Ronai
Keyword(s):  
Egg Production ◽  
Social Insect ◽  
Royal Jelly ◽  
High Volume ◽  
Division Of Labour ◽  
Stingless Bee ◽  
Reproductive Capacity ◽  
Ovary Activation ◽  
Worker Sterility ◽  
Insect Reproduction

ABSTRACTSocial insect reproduction is characterised by a division of labour. Typically, the queen is the sole reproductive female in the colony and the female workers are non-reproductive. However, in the majority of social insect species the workers are only facultatively sterile and remain capable of laying eggs under some conditions, such as when the queen dies. The Australian stingless bee Tetragonula carbonaria is noteworthy as workers never lay eggs, even if a colony loses its queen. Here we describe the reproductive anatomy of T. carbonaria workers (deactivated ovaries), virgin queens (semi-activated ovaries), and mated queens (activated ovaries). T. carbonaria mated queens have high-volume egg production compared to other female insects as each of their eight ovarioles (filaments of the ovary) produces approximately 40 eggs per day. We then conduct the first experimental test of absolute worker sterility in the social insects. Using a controlled microcolony environment, we investigate whether the reproductive capacity of adult workers can be rescued by manipulating the workers’ social environment (separating them from a queen) and diet (feeding them unrestricted highly nutritious honey bee royal jelly), both conditions which cause ovary activation in bee species where workers are facultatively sterile. The ovaries of T. carbonaria workers that are queenless and fed royal jelly remain non-functional, indicating they are irreversibly sterile and that ovary degeneration is fixed prior to adulthood. We suggest that T. carbonaria might have evolved absolute worker sterility because colonies under natural conditions are unlikely to ever be queenless.

Factors affecting ovary activation in honey bee workers: a meta-analysis

2012 ◽  
Vol 59 (3) ◽  
pp. 381-388 ◽  
Author(s):  
A. G. Backx ◽  
E. Guzmán-Novoa ◽  
G. J. Thompson
Keyword(s):  
Honey Bee ◽  
Meta Analysis ◽  
Factors Affecting ◽  
Ovary Activation ◽  
Honey Bee Workers

scholarly journals Correlation of Royal Jelly composition with swarming tendency in Honey Bees (Apis mellifera): A Review

2021 ◽  
Author(s):  
Ivy Neha Chander ◽  
Lovleen Marwaha
Keyword(s):  
Honey Bees ◽  
Egg Production ◽  
Royal Jelly ◽  
Review Paper ◽  
Queen Pheromone ◽  
Eusocial Insects ◽  
Warm Weather ◽  
Growth Development ◽  
The Impact ◽  
Swarming Behaviour

Honey bees are eusocial insects which respond to warm weather, abundant food source by increasing their population through swarming to ensure the survival of the colony. To maintain a superior colony a queen must have a nutrient-rich diet and high egg production. Royal jelly is a high-quality food which has numerous beneficial properties required for proper growth, development, survival of the queen. Factors like congestion, lack of adequate queen pheromone, abnormal queen pheromone, pathogenic infections, exposure to pesticides influence the queen quality which further promotes non-reproductive swarming behaviour. Worker bees analyse the queen condition to prepare for supersedure or emergency queen rearing. This review paper highlights the influence of royal jelly composition on the queen quality, the impact of queen quality on swarming tendency, correlation between royal jelly composition and swarming tendency.

scholarly journals Ovary activation does not correlate with pollen and nectar foraging specialization in the bumblebeeBombus impatiens

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4415
Author(s):  
Meagan A. Simons ◽  
Adam R. Smith
Keyword(s):  
Foraging Activity ◽  
Sensory Sensitivity ◽  
Reproductive Conflict ◽  
Proboscis Extension Response ◽  
Ovary Activation ◽  
Ground Plan ◽  
Nectar Preference ◽  
Mixed Support ◽  
Proboscis Extension ◽  
Foraging Specialization

Social insect foragers may specialize on certain resource types. Specialization on pollen or nectar among honeybee foragers is hypothesized to result from associations between reproductive physiology and sensory tuning that evolved in ancestral solitary bees (the Reproductive Ground-Plan Hypothesis; RGPH). However, the two non-honeybee species studied showed no association between specialization and ovary activation. Here we investigate the bumblebeeB. impatiensbecause it has the most extensively studied pollen/nectar specialization of any bumblebee. We show that ovary size does not differ between pollen specialist, nectar specialist, and generalist foragers, contrary to the predictions of the RGPH. However, we also found mixed support for the second prediction of the RGPH, that sensory sensitivity, measured through proboscis extension response (PER), is greater among pollen foragers. We also found a correlation between foraging activity and ovary size, and foraging activity and relative nectar preference, but no correlation between ovary size and nectar preference. In one colony non-foragers had larger ovaries than foragers, supporting the reproductive conflict and work hypothesis, but in the other colony they did not.

Molecular basis of transcriptional silencing in budding yeast

2004 ◽  
Vol 82 (4) ◽  
pp. 413-418 ◽  
Author(s):  
Lingyi Chen ◽  
Jonathan Widom
Keyword(s):  
Rna Polymerase Ii ◽  
Molecular Basis ◽  
Chromosomal Location ◽  
Transcriptional Silencing ◽  
Regulatory Proteins ◽  
Specific Gene ◽  
Activator Proteins ◽  
Target Sites ◽  
New Ideas ◽  
Heterochromatin Structure

Transcriptional silencing is a phenomenon in which the transcription of genes by RNA polymerase II or III is repressed, dependent on the chromosomal location of a gene. Transcriptional silencing normally occurs in highly condensed heterochromatin regions of the genome, suggesting that heterochromatin might repress transcription by restricting the ability of sequence-specific gene activator proteins to access their DNA target sites. However, recent studies show that heterochromatin structure is inherently dynamic, and that sequence-specific regulatory proteins are able to bind to their target sites in heterochromatin. The molecular basis of transcriptional silencing is plainly more complicated than simple steric exclusion. New ideas and experiments are needed.Key words: transcriptional silencing, heterochromatin, accessibility.

scholarly journals Rewiring of the ubiquitinated proteome determines ageing in C. elegans

Nature ◽  
2021 ◽  
Author(s):  
Seda Koyuncu ◽  
Rute Loureiro ◽  
Hyun Ju Lee ◽  
Prerana Wagle ◽  
Marcus Krueger ◽  
...  
Keyword(s):  
Cell Function ◽  
Insulin Signalling ◽  
Bacterial Colonization ◽  
Regulatory Proteins ◽  
C Elegans ◽  
Intestinal Integrity ◽  
Age Related ◽  
Subsequent Degradation ◽  
Cellular Integrity

AbstractAgeing is driven by a loss of cellular integrity1. Given the major role of ubiquitin modifications in cell function2, here we assess the link between ubiquitination and ageing by quantifying whole-proteome ubiquitin signatures in Caenorhabditis elegans. We find a remodelling of the ubiquitinated proteome during ageing, which is ameliorated by longevity paradigms such as dietary restriction and reduced insulin signalling. Notably, ageing causes a global loss of ubiquitination that is triggered by increased deubiquitinase activity. Because ubiquitination can tag proteins for recognition by the proteasome3, a fundamental question is whether deficits in targeted degradation influence longevity. By integrating data from worms with a defective proteasome, we identify proteasomal targets that accumulate with age owing to decreased ubiquitination and subsequent degradation. Lowering the levels of age-dysregulated proteasome targets prolongs longevity, whereas preventing their degradation shortens lifespan. Among the proteasomal targets, we find the IFB-2 intermediate filament4 and the EPS-8 modulator of RAC signalling5. While increased levels of IFB-2 promote the loss of intestinal integrity and bacterial colonization, upregulation of EPS-8 hyperactivates RAC in muscle and neurons, and leads to alterations in the actin cytoskeleton and protein kinase JNK. In summary, age-related changes in targeted degradation of structural and regulatory proteins across tissues determine longevity.

New α-Granule Biology Reveals How Platelets May Regulate Angiogenesis

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. SCI-35-SCI-35
Author(s):  
Joseph E. Italiano ◽  
Elisabeth M. Battinelli
Keyword(s):  
Molecular Basis ◽  
Conflicts Of Interest ◽  
Local Environment ◽  
Regulatory Proteins ◽  
Angiogenic Potential ◽  
Angiogenic Response ◽  
Filament Assembly ◽  
Activated Platelets ◽  
Vessel Growth ◽  
New Form

Abstract Abstract SCI-35 In addition to their “classic” role in hemostasis, platelets are now known to be major contributors in wound healing, tumor growth, and angiogenesis. Stored within the α-granules is an array of angiogenic regulatory proteins, which are deposited by the secretion reaction of surface-activated platelets into the local environment of a tumor or wound. Despite the recognized importance of platelets in regulating new blood vessel growth, our understanding of how platelets modulate the angiogenic response remains unclear. Here, we consider how new α-granule biology may provide insights into how platelets regulate angiogenesis. First, we will present data on a new form of α-granule movement. We will show that actin filament assembly can power the propulsion of α-granule movement, and this may be a novel mechanism underlying the secretion reaction. Second, we show that one mechanism by which anticoagulants may impact malignancy is by disrupting the tumor cells' ability to hijack the angiogenic potential of platelets. Third, we will review the molecular basis of transport and delivery of α-granules to assembling platelets. Finally, we will discuss the concept of using “designer platelets” as a drug delivery system for targeted agents. Disclosures: No relevant conflicts of interest to declare.

foxo is required for resistance to amino acid starvation in Drosophila

Genome ◽  
2008 ◽  
Vol 51 (8) ◽  
pp. 668-672 ◽  
Author(s):  
Jamie M. Kramer ◽  
Jennifer D. Slade ◽  
Brian E. Staveley
Keyword(s):  
Amino Acid ◽  
Insulin Signalling ◽  
Amino Acid Starvation ◽  
Reproductive Capacity ◽  
Luciferase Reporter ◽  
Loss Of Function ◽  
Luciferase Reporter Gene ◽  
Insulin Signalling Pathway ◽  
Evolutionarily Conserved ◽  
Sense And Respond

The ability of an organism to alter its metabolism, growth, and reproductive capacity in response to fluctuations in food availability has likely been an important factor in the course of evolution. The insulin signalling pathway is an evolutionarily conserved mechanism used by metazoan animals to sense and respond to changes in nutrient intake. During conditions of starvation the level of circulating insulin is low. Under conditions of low insulin, the foxo family of transcription factors are activated. Studies in Drosophila suggest that Drosophila foxo may alter the transcriptional profile of cells to allow for maximum survival of the fly during starvation. We have tested this ability in transgenic flies containing a luciferase reporter gene under the control of foxo response elements. We show that foxo activity is increased during amino acid starvation and reduced in the presence of amino acids. In addition, we find that loss of function of foxo leads to reduced survival under conditions of amino acid starvation in both larvae and adult flies. These data provide direct evidence that foxo is activated during amino acid starvation and is critical for optimal survival under these conditions.

Abstract 1880: Molecular Basis of Inward-Rectifier Potassium Current Upregulation in Human Atrial Fibrillation: Contrasting Mechanisms for I K1 versus Constitutive I KACh

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Zenawit Girmatsion ◽  
Peter Biliczki ◽  
Angelika Kuehbacher ◽  
Mirella Scherer ◽  
Gerhard Wimmer-Greinecker ◽  
...  
Keyword(s):  
Atrial Fibrillation ◽  
Protein Expression ◽  
G Protein ◽  
Molecular Basis ◽  
Potassium Current ◽  
Inward Rectifier ◽  
Regulatory Proteins ◽  
Mrna Levels ◽  
Inhibitory G Protein ◽  
Human Atrial Fibrillation

Introduction: Upregulation of Kir-based inward rectifiers I K1 and constitutively active acetylcholine-regulated current (I KACh,c ) is a prominent contributor to atrial fibrillation (AF) maintenance. This study assessed occurrence and molecular basis of altered I K1 and I KACh,c in man. Methods: Left atrial samples from mitral valve repair patients (n = 21 AF; n = 20 SR) were studied. Patch-clamp was applied to record currents. Immunoblots and confocal microscopy were used to study protein content and localization. Quantitative real-time PCR was performed to study microRNA and mRNA levels. Results: I K1 and I KACh,c densities were greater in cells from AF than SR patients (at −120 mV: 3.5 ± 2.6 vs. 2.1 ± 1.1 pA/pF for I K1 and 1.3 ± 0.8 vs. 0.4 ± 0.3 pA/pF for I KACh,c ). Kir2.1 protein (underlying I K1 ) was increased by AF (Fig. ) but Kir2.3 was unchanged. Kir2.1 mRNA was increased and Kir2.3 mRNA reduced. Kir3.1 and Kir3.4 (underlying I KACh,c ) protein was unaffected. The inhibitory regulatory G-protein G αi-3 was downregulated, potentially explaining increased free G αγ and I KACh,c . No change in other regulatory proteins (RGS4, calmodulin) or subcellular channel and regulatory proteins localization occurred with AF. Kir2.1 protein expression is known to be downregulated by the microRNA miR-1: miR-1 expression was reduced by AF (Fig. ). Conclusions: Both inward rectifier currents I K1 and I KACh,c are increased in human AF. I K1 changes are caused by increased protein expression through transcriptional and post-transcriptional modifications related to miR-1 downregulation, whereas the increase in I KACh,c is functional, possibly mediated by decreased inhibitory G-protein expression.

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