Understanding the social evolution leading to insect eusociality requires, among other, a detailed insight into endocrine regulatory mechanisms that have been co-opted from solitary ancestors to play new roles in the complex life histories of eusocial species. Bumblebees represent well-suited models of a relatively primitive social organization standing on the mid-way to highly advanced eusociality and their queens undergo both, a solitary and a social phase, separated by winter diapause. In the present paper, we characterize the gene expression levels of major endocrine regulatory pathways across tissues, sexes, and life-stages of the buff-tailed bumblebee, Bombus terrestris, with special emphasis on critical stages of the queen's transition from solitary to social life. We focused on fundamental genes of three pathways: (1) Forkhead box protein O and insulin/insulin-like signaling, (2) Juvenile hormone (JH) signaling, and (3) Adipokinetic hormone signaling. Virgin queens were distinguished by higher expression of forkhead box protein O and downregulated insulin-like peptides and JH signaling, indicated by low expression of methyl farnesoate epoxidase (MFE) and transcription factor Krüppel homolog 1 (Kr-h1). Diapausing queens showed the expected downregulation of JH signaling in terms of low MFE and vitellogenin (Vg) expressions, but an unexpectedly high expression of Kr-h1. By contrast, reproducing queens revealed an upregulation of MFE and Vg together with insulin signaling. Surprisingly, the insulin growth factor 1 (IGF-1) turned out to be a queen-specific hormone. Workers exhibited an expression pattern of MFE and Vg similar to that of reproducing queens. Males were characterized by high Kr-h1 expression and low Vg level. The tissue comparison unveiled an unexpected resemblance between the fat body and hypopharyngeal glands across all investigated genes, sexes, and life stages.
Lactobacillus bombi sp. nov., from the digestive tract of laboratory-reared bumblebee queens (Bombus terrestris) Three bacterial strains belonging to the genus Lactobacillus were isolated from the digestive tracts of laboratory-reared bumblebee queens (Bombus terrestris) using MRS agar under anaerobic conditions. The isolates were identified according to 16S rRNA gene sequence analysis as undescribed members of the genus Lactobacillus, with the highest 16S rRNA gene sequence similarity (96.9 %) to the uncharacterized bacterial strain Lactobacillus sp. Mboho2r2 isolated from the stomach of a European honeybee (Apis mellifera). Lactobacillus tucceti was found to be the closest related species with a validly published name, with 92.9 % 16S rRNA gene sequence similarity to the type strain. However, phylogenetic analyses based on different markers revealed that this species is phylogenetically very distant from the novel strains. The DNA G+C content of the proposed type strain BTLCH M1/2 T is 37.8 mol%. The fatty acids C 19 : 1 v6c and/or C 19 : 0 cyclo v10c/19v6, C 18 : 1 v9c and C 16 : 0 were predominant in all strains. Diphosphatidylglycerol, phosphatidylglycerol, a phospholipid, seven glycolipids and two phosphoglycolipids were detected in the novel strains. Growth was observed at 47 6C. The peptidoglycan type A4a L-Lys-D-Asp was determined for strain BTLCH M1/2 T. Genotypic characteristics and phylogenetic analyses based on the phylogenetic markers hsp60, pheS, rpoA and tuf as well as phenotypic characteristics and the results of chemotaxonomic analyses confirmed that the new isolates belong to a novel species of the genus Lactobacillus, for which the name Lactobacillus bombi sp. nov. is proposed. The type strain is BTLCH M1/2 T (5DSM 26517 T 5CCM 8440 T).
Domestic gardens supply pollinators with valuable habitats, but the risk of exposure to pesticides has been little investigated. Artificial nesting shelters of a red mason bee species (Osmia bicornis) were placed in two suburban gardens and two commercial fruit orchards to determine the contamination of forage sources by pesticides. Larval pollen provisions were collected from a total of 14 nests. They consisted mainly of pollen from oaks (65–100% weight/sample), Brassicaceae (≤34% w/s) and fruit trees (≤1.6% w/s). Overall, 30 pesticides were detected and each sample contained a mixture of 11–21 pesticide residues. The pesticide residues were significantly lower in garden samples than in orchard samples. The difference was attributed mainly to the abundant fungicides pyrimethanil and boscalid, which were sprayed in fruit orchards and were present on average at 1004 ppb and 648 ppb in orchard samples, respectively. The results suggested that pollinators can benefit from domestic gardens by foraging from floral sources less contaminated by pesticides than in adjacent croplands.
The rearing method under controlled conditions known for Bombus terrestris was successful in initiating egg-laying for 83% of B. pascuorum queens. After larvae had hatched, fresh pollen pellets needed to be inserted into brood pockets daily. After the first workers had emerged, colony development was advanced by placing them outdoors and supplying them with a sugar solution and pollen. The bees were able to use tightly pressed pollen from small plastic pots inserted near the brood. This feeding resulted in large colonies that produced dozens of young queens. In contrast, colonies managed in the laboratory were unable to utilize pollen in a similar manner. They raised only a few workers and several queens. Mating young queens was easy. It was stimulated by daylight, but in the case of B. humilis by direct sunshine. Several B. pascuorum and B. sylvarum queens were overwintered and began the new generation under artificial conditions. However, a lack of fresh pollen limited the development of colonies outside of the vegetation period.
Two‐dimensional comprehensive gas chromatography (GC×GC) coupled with mass detection was used as a tool for biosynthetic studies of bumblebee pheromones. Prior to biosynthetic experiments, the chromatographic behaviour of isotopically modified esters in the GC×GC system as well as their behaviour in mass detection was studied. The male marking pheromones of Bombus lucorum, Bombus lapidarius and Bombus terrestris were investigated. Main pheromonal components are ethyl tetradec‐9‐enoate (53 %) and ethyl dodecanoate (6 %) in B. lucorum, hexadec‐9‐en‐1‐ol (52 %) and hexadecan‐1‐ol (31 %) in B. lapidarius, and 2,3‐dihydrofarnesol (58 %) and ethyl dodecanoate (15 %) in B. terrestris. The research strategy was based on 1) in vivo incubation of isotopically (2H, 13C) modified fatty acids (FAs) and analysis of their metabolites and 2) feeding experiments with 2H‐ and 13C‐labelled FAs mixed with food. It was observed that labelled FAs were modified into the most abundant aliphatic compounds present in labial gland secretions. In feeding experiments, the labelled FAs were transformed into pheromone components. Transport of the FA precursors from the fat body through haemolymph was confirmed. The results show that FAs, stored in the form of triacylglycerols in the fat body, are likely to participate in the biosynthesis of some aliphatic pheromone components.
Insects’ fat bodies are responsible for nutrient storage and for a significant part of intermediary metabolism. Thus, it can be expected that the structure and content of the fat body will adaptively change, if an insect is going through different life stages. Bumblebee queens belong to such insects as they dramatically change their physiology several times over their lives in relation to their solitary overwintering, independent colony foundation stage, and during the colony life-cycle ending in the senescent stage. Here, we report on changes in the ultrastructure and lipid composition of the peripheral fat body of Bombus terrestris queens in relation to seasonal changes in the queens’ activity. Six life stages are defined and evaluated in particular: pharate, callow, before and after hibernation, egg-laying, and senescence. Transmission electron microscopy revealed that the fat body contained two main cell types–adipocytes and oenocytes. Only adipocytes reveal important changes related to the life phase, and mostly the ration between inclusion and cytoplasm volume varies among particular stages. Both electron microscopy and chemical analyses of lipids highlighted seasonal variability in the quantity of the stored lipids, which peaked prior to hibernation. Triacylglycerols appeared to be the main energy source during hibernation, while the amount of glycogen before and after hibernation remained unchanged. In addition, we observed that the representation of some fatty acids within the triacylglycerols change during the queen’s life. Last but not least, we show that fat body cell membranes do not undergo substantial changes concerning phospholipid composition in relation to overwintering. This finding supports the hypothesis that the cold-adaptation strategy of bumblebee queens is more likely to be based on polyol accumulation than on the restructuring of lipid membranes.
New requirements regarding agriculture production together with the increased pressure on environmentally friendly practices leave almost no space for the routine agriculture production. Innovations that include environmental changes are therefore essential. Agricultural research faces various challenges associated with the quality and eff ectiveness of agriculture production and recently also with the environmental and sustainability issues. Th e paper provides a case study focused on the environmental and social evaluation of a biological asset that constitutes an agricultural innovation. Th is paper also shows a concrete example of how the social and environmental reporting can be constructed and implemented by providing an evaluation of a Bumblebee Nest. As a result, the total value consisting of the market, ecosystem and aesthetic value is provided. Although the market value comprises the largest proportion of the total value, it does not exceed 64%.
In contrast to the catalytic subunit of telomerase, its RNA subunit (TR) is highly divergent in size, sequence and biogenesis pathways across eukaryotes. Current views on TR evolution assume a common origin of TRs transcribed with RNA polymerase II in Opisthokonta (the supergroup including Animalia and Fungi) and Trypanosomida on one hand, and TRs transcribed with RNA polymerase III under the control of type 3 promoter, found in TSAR and Archaeplastida supergroups (including e.g. ciliates and Viridiplantae taxa, respectively). Here, we focus on unknown TRs in one of the largest Animalia order - Hymenoptera (Arthropoda) with more than 300 available representative genomes. Using a combination of bioinformatic and experimental approaches, we identify their TRs. In contrast to the presumed type of TRs (H/ACA box snoRNAs transcribed with RNA Polymerase II) corresponding to their phylogenetic position, we find here short TRs of the snRNA type, likely transcribed with RNA polymerase III under the control of the type 3 promoter. The newly described insect TRs thus question the hitherto assumed monophyletic origin of TRs across Animalia and point to an evolutionary switch in TR type and biogenesis that was associated with the divergence of Arthropods.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.