scholarly journals Neutral Sterols of Cephalic Glands of Stingless Bees and Their Correlation with Sterols from Pollen

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Maria Juliana Ferreira-Caliman ◽  
Cláudia Inês da Silva ◽  
Sidnei Mateus ◽  
Ronaldo Zucchi ◽  
Fabio Santos do Nascimento
Keyword(s):  
Stingless Bees ◽  
De Novo ◽  
Membrane Lipid ◽  
Floral Resources ◽  
Phytophagous Insects ◽  
Social Bees ◽  
Melipona Marginata ◽  
Neutral Sterols ◽  
Growth Development ◽  
Exogenous Source

Sterols are essential molecules in the membrane lipid composition and precursors of important sterol hormones that regulate many developmental processes. Insects are unable to synthesize sterolsde novoand, thus, all phytophagous insects depend on an exogenous source of sterols for growth, development, and reproduction. The sterol requirements of social bees are not fully known due to the fact that there is no well-defined diet available throughout the year with regard to floral resources. Our study aimed to characterize the sterols present in pollen stored inMelipona marginataandMelipona scutellariscolonies, as well as evaluating their presence in the mandibular, hypopharyngeal, and cephalic salivary gland secretions. We analyzed the chemical composition of pollen stored in the colonies and the composition of the cephalic glands of workers in three adult functional phases (newly emerged, nurses, and foragers) by gas chromatography and mass spectrometry. The results showed that the pollen analyzed contained campesterol, stigmasterol, sitosterol, isofucosterol, lanosterol, and small amounts of cholesterol. The glands showed the same compounds found in the pollen analyzed, except lanosterol that was not found inM. scutellarisglands. Surprisingly, cholesterol was found in some glands with relative ratios greater than those found in pollen.

scholarly journals Lipid Acyl Chain Remodeling in Yeast

2015 ◽  
Vol 8s1 ◽  
pp. LPI.S31780 ◽  
Author(s):  
Mike F. Renne ◽  
Xue Bao ◽  
Cedric H. De Smet ◽  
Anton I. P. M. De Kroon
Keyword(s):  
Intracellular Transport ◽  
De Novo ◽  
Acyl Chain ◽  
Model Organism ◽  
Lipid Synthesis ◽  
Membrane Lipid ◽  
Lipid Homeostasis ◽  
Synthetic Process ◽  
Acyl Chains ◽  
Phospholipid Acyl Chain

Membrane lipid homeostasis is maintained by de novo synthesis, intracellular transport, remodeling, and degradation of lipid molecules. Glycerophospholipids, the most abundant structural component of eukaryotic membranes, are subject to acyl chain remodeling, which is defined as the post-synthetic process in which one or both acyl chains are exchanged. Here, we review studies addressing acyl chain remodeling of membrane glycerophospholipids in Saccharomyces cerevisiae, a model organism that has been successfully used to investigate lipid synthesis and its regulation. Experimental evidence for the occurrence of phospholipid acyl chain exchange in cardiolipin, phosphatidylcholine, phosphatidylinositol, and phosphatidylethanolamine is summarized, including methods and tools that have been used for detecting remodeling. Progress in the identification of the enzymes involved is reported, and putative functions of acyl chain remodeling in yeast are discussed.

scholarly journals High light induces species specific changes in the membrane lipid composition of Chlorella

2020 ◽  
Vol 477 (13) ◽  
pp. 2543-2559
Author(s):  
Janka Widzgowski ◽  
Alexander Vogel ◽  
Lena Altrogge ◽  
Julia Pfaff ◽  
Heiko Schoof ◽  
...  
Keyword(s):  
Cell Membranes ◽  
De Novo ◽  
Algal Cell ◽  
Isotopic Labeling ◽  
Biochemical Properties ◽  
Membrane Lipid ◽  
Light Conditions ◽  
Hydrophobic Barrier ◽  
Glycerolipid Composition ◽  
Species Specific

Algae have evolved several mechanisms to adjust to changing environmental conditions. To separate from their surroundings, algal cell membranes form a hydrophobic barrier that is critical for life. Thus, it is important to maintain or adjust the physical and biochemical properties of cell membranes which are exposed to environmental factors. Especially glycerolipids of thylakoid membranes, the site of photosynthesis and photoprotection within chloroplasts, are affected by different light conditions. Since little is known about membrane lipid remodeling upon different light treatments, we examined light induced alterations in the glycerolipid composition of the two Chlorella species, C. vulgaris and C. sorokiniana, which differ strongly in their ability to cope with different light intensities. Lipidomic analysis and isotopic labeling experiments revealed differences in the composition of their galactolipid species, although both species likely utilize galactolipid precursors originated from the endoplasmic reticulum. However, in silico research of de novo sequenced genomes and ortholog mapping of proteins putatively involved in lipid metabolism showed largely conserved lipid biosynthesis pathways suggesting species specific lipid remodeling mechanisms, which possibly have an impact on the response to different light conditions.

scholarly journals A key to the genera and subgenera of stingless bees in Indonesia (Hymenoptera: Apidae)

TREUBIA ◽  
2019 ◽  
Vol 45 ◽  
pp. 65-84 ◽  
Author(s):  
Michael S. Engel ◽  
Sih Kahono ◽  
Djunijanti Peggie
Keyword(s):  
Stingless Bees ◽  
Stingless Bee ◽  
Social Bees

Indonesia harbors the greatest diversity of social bees in all of Asia, particularly of the stingless bees (Apidae: Apinae: Meliponini). Presently, 46 species of stingless bees are known across Indonesia although records are not comprehensive and additional diversity is likely present across the region.  All of the known Asiatic genera of Meliponini occur in Indonesia, making this region a critical center of modern stingless bee biodiversity in Asia. Presented here is an illustrated key to the genera and subgenera of Indonesian stingless bees, as an aid to the general identification, study, and conservation of these critical pollinators.

scholarly journals Altered miRNA and mRNA Expression in Sika Deer Skeletal Muscle with Age

Genes ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 172
Author(s):  
Boyin Jia ◽  
Yuan Liu ◽  
Qining Li ◽  
Jiali Zhang ◽  
Chenxia Ge ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Growth And Development ◽  
Molecular Mechanisms ◽  
Muscle Development ◽  
Sika Deer ◽  
De Novo ◽  
Expression Profiles ◽  
Differentially Expressed ◽  
Growth Development ◽  
Development And Aging

Studies of the gene and miRNA expression profiles associated with the postnatal late growth, development, and aging of skeletal muscle are lacking in sika deer. To understand the molecular mechanisms of the growth and development of sika deer skeletal muscle, we used de novo RNA sequencing (RNA-seq) and microRNA sequencing (miRNA-seq) analyses to determine the differentially expressed (DE) unigenes and miRNAs from skeletal muscle tissues at 1, 3, 5, and 10 years in sika deer. A total of 51,716 unigenes, 171 known miRNAs, and 60 novel miRNAs were identified based on four mRNA and small RNA libraries. A total of 2,044 unigenes and 11 miRNAs were differentially expressed between adolescence and juvenile sika deer, 1,946 unigenes and 4 miRNAs were differentially expressed between adult and adolescent sika deer, and 2,209 unigenes and 1 miRNAs were differentially expressed between aged and adult sika deer. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses showed that DE unigenes and miRNA were mainly related to energy and substance metabolism, processes that are closely associate with the growth, development, and aging of skeletal muscle. We also constructed mRNA–mRNA and miRNA–mRNA interaction networks related to the growth, development, and aging of skeletal muscle. The results show that mRNA (Myh1, Myh2, Myh7, ACTN3, etc.) and miRNAs (miR-133a, miR-133c, miR-192, miR-151-3p, etc.) may play important roles in muscle growth and development, and mRNA (WWP1, DEK, UCP3, FUS, etc.) and miRNAs (miR-17-5p, miR-378b, miR-199a-5p, miR-7, etc.) may have key roles in muscle aging. In this study, we determined the dynamic miRNA and unigenes transcriptome in muscle tissue for the first time in sika deer. The age-dependent miRNAs and unigenes identified will offer insights into the molecular mechanism underlying muscle development, growth, and maintenance and will also provide valuable information for sika deer genetic breeding.

scholarly journals Lipid synthesis in human erythroid cells: the effect of sickling

Blood ◽  
1976 ◽  
Vol 47 (2) ◽  
pp. 189-195 ◽  
Author(s):  
TA Lane ◽  
SK Ballas ◽  
ER Burka
Keyword(s):  
Cell Membrane ◽  
Neutral Lipid ◽  
Sickle Cell Anemia ◽  
De Novo ◽  
Membrane Lipids ◽  
Membrane Damage ◽  
Lipid Synthesis ◽  
Membrane Lipid ◽  
Erythroid Cell ◽  
Cell Membrane Damage

Abstract Human reticulocytes are capable of synthesizing membrane lipids from 14C-glycerol de novo. In both sickle and nonsickle reticulocytes the majority of 14C-glycerol was incorporated into phospholipids, primarily phosphatidylserine and phosphatidylcholine. Incorporation into sphingomyelin was minimal. The most abundant neutral lipid synthesized was triglyceride. In the absence of sickling, the rate of lipid synthesis in sickle reticulocytes was similar to that of nonsickle reticulocytes. With the induction of sickling under anoxic conditions sickle reticulocytes showed a prompt increase in the rate of lipid synthesis to an average of 69% above control values, while nonsickle reticulocytes under similar conditions decreased the rate of lipid synthesis. An increase in the rate of membrane lipid synthesis is associated in the mammalian erythroid cell with cell membrane damage. The findings further confirm that lesions of the erythroid cell membrane in sickle cell anemia are secondary to the sickling process itself.

scholarly journals ON THE NATURE OF SPOROGENESIS IN SOME AEROBIC BACTERIA

1952 ◽  
Vol 35 (6) ◽  
pp. 907-927 ◽  
Author(s):  
W. A. Hardwick ◽  
J. W. Foster
Keyword(s):  
De Novo ◽  
Enzyme Synthesis ◽  
Aerobic Bacteria ◽  
Low Molecular Weight ◽  
Inhibitory Effects ◽  
Nitrogenous Substances ◽  
Enzyme Formation ◽  
Spore Forming Bacteria ◽  
Endogenous Process ◽  
Exogenous Source

Washed vegetative cells of various species of aerobic spore-forming bacteria sporulate abundantly when shaken in distilled water in air. The spores thus formed possess the same heat resistance as spores formed in a complete growth medium. Various factors influencing sporogenesis in water are described. Glucose in low concentration completely suppresses sporogenesis under these conditions and the suppression is relieved by the presence of ammonia as an exogenous source of nitrogen. Various amino acid and purine antimetabolite analogues inhibit sporogenesis and their inhibitory effects are completely reversed by much smaller amounts of the corresponding metabolites. Sporogenesis is thus regarded as a de novo synthesis of spore proteins from preexisting endogenous (enzyme) proteins. Cells low in protein fail to sporulate and the capacity of the cell to adaptively attack maltose and trehalose is strongly interfered with after the cell is irreversibly committed to sporulation, but not before that. Evidence is advanced supporting the hypothesis that sporogenesis is an endogenous process which commences when the supply of exogenous energy and carbon is depleted. It utilizes low molecular weight nitrogenous substances liberated by the degradation of preexisting enzyme proteins of the vegetative cell. Sporogenesis and adaptive enzyme formation are regarded as competitive synthetic processes, both utilizing endogenous enzyme proteins. The events of sporogenesis suggest that this process may be an adaptive protein synthesis, analogous to adaptive enzyme synthesis.

Defense peptides: recent developments

2015 ◽  
Vol 6 (4) ◽  
pp. 237-251 ◽  
Author(s):  
Małgorzata Cytryńska ◽  
Agnieszka Zdybicka-Barabas
Keyword(s):  
De Novo ◽  
Current Knowledge ◽  
Membrane Lipid ◽  
Factors Affecting ◽  
Natural Defense ◽  
Secreted Factors ◽  
Recent Developments ◽  
Extracellular Proteinases ◽  
Defense Peptides ◽  
Conventional Antibiotics

AbstractDefense peptides are small amphipathic molecules that exhibit antimicrobial, antitumor, antiviral, and immunomodulatory properties. This review summarizes current knowledge on the mechanisms of antimicrobial activity of cationic and anionic defense peptides, indicating peptide-based as well as microbial cell-based factors affecting this activity. The peptide-based factors include charge, hydrophibicity, and amphipathicity, whereas the pathogen-based factors are membrane lipid composition, presence of sterols, membrane fluidity, cell wall components, and secreted factors such as extracellular proteinases. Since defense peptides have been considered very promising molecules that could replace conventional antibiotics in the era of drug-resistant pathogens, the issue of microbial resistance to antimicrobial peptides (AMPs) is addressed. Furthermore, selected approaches employed for optimization and de novo design of effective AMPs based on the properties recognized as important for the function of natural defense peptides are presented.

scholarly journals Food niche of solitary and social bees (Hymenoptera: Apoidea) in a Neotropical Savanna

Sociobiology ◽  
2020 ◽  
Vol 67 (4) ◽  
pp. 554
Author(s):  
Claudia Oliveira dos Santos ◽  
Cândida Maria Lima Aguiar ◽  
Celso Feitosa Martins ◽  
Edson Braz Santana ◽  
Flávio França ◽  
...  
Keyword(s):  
Plant Species ◽  
Niche Overlap ◽  
Trophic Niche ◽  
Floral Resources ◽  
Neotropical Savanna ◽  
Social Bees ◽  
Long Period ◽  
Food Niche ◽  
Trophic Niches

In this study we investigated the group of floral resources that support bee populations from a bee assemblage in a savanna, and the way in which bee species use these food resources, with an emphasis on the breadth and overlap of trophic niches. The interactions between 75 species of bees and 62 species of plants visited to obtain floral resources were recorded on a Brazilian savanna site. The bee species explored a diverse set of plant species, but concentrated the collection of resources in a few plant species. The distribution of the samples over a long period favored a robust characterization of the food niche of the bee populations. Byrsonima sericea, Serjania faveolata, and Stigmaphyllon paralias were the plant species with the highest number of links with bees. In general, the trophic niche overlap was low, with 75% of pairs of bee species having a niche overlap (NO) less than 0.33. Only four pairs showed high overlap (NO>0.70) and all cases were related to the exploitation of floral resources provided by B. sericea, a key resource for the maintenance of the local bee fauna, an oil and pollen provider.

scholarly journals Stingless bee floral visitation in the global tropics and subtropics

2021 ◽  
Author(s):  
Francisco Garcia Bulle Bueno ◽  
Liam Kendall ◽  
Denise Araujo Alves ◽  
Manuel Lequerica Tamara ◽  
Tim Heard ◽  
...  
Keyword(s):  
Stingless Bees ◽  
Native Plants ◽  
Ornamental Plants ◽  
Terrestrial Ecosystems ◽  
Stingless Bee ◽  
Wild Plants ◽  
Plant Interactions ◽  
Social Bees ◽  
Floral Visitation ◽  
Plant Families

AbstractBees play a key role in maintaining healthy terrestrial ecosystems by pollinating plants. Stingless bees (Apidae: Meliponini) are a diverse clade of social bees (>500 species) with a pantropical distribution spanning South and Central America, Africa, India and Austral-Asia. They are garnering increasing attention as commercially-beneficial pollinators of some crops, yet their contribution to the pollination of native plants in the tropics and subtropics remains poorly understood. Here we conduct for the first time a global review of the plants visited by stingless bees. We compile a database of reported associations (flower visits) between stingless bees and plants, from studies that have made either direct observations of foraging bees or analysed the pollen stored in nests. Worldwide, we find stingless bees have been reported to visit the flowers of plants from at least 215 different families and 1434 genera, with frequently reported interactions for many of the tropic’s most species-diverse plant families including Fabaceae, Asteraceae, Rubiaceae, Poaceae, Euphorbiaceae, Myrtaceae, Malvaceae, Arecaceae, Solanaceae, and Anacardiaceae. The stingless bee fauna of each of three major biogeographic regions (Neotropical, Afrotropical and Indo-Malayan-Australasian) were frequent visitors of many of the same plant families, however we detected differences in the proportional use of plant families by the stingless bees of the Indo-Malayan-Australasian and Neotropical regions, likely reflecting differences in the available flora of those regions. Stingless bees in all regions visit a range of exotic species in their preferred plant families (crops, ornamental plants and weeds), in addition to native plants. Although most reports of floral visitation on wild plants do not confirm effective pollen transfer, it is likely that stingless bees make at least some contribution to pollination for the majority of plants they visit. In all, our database supports the view that stingless bees play an important role in the ecosystems of the global tropics and subtropics as pollinators of an exceptionally large and diverse number of plants. This database also highlights important gaps in our knowledge of stingless bee resource use and should benefit future efforts to understand stingless bee-plant interactions.

scholarly journals Resin Use by Stingless Bees: A Review

Insects ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 719
Author(s):  
Maggie Shanahan ◽  
Marla Spivak
Keyword(s):  
Land Use ◽  
Microbial Communities ◽  
Stingless Bees ◽  
Stingless Bee ◽  
Future Research ◽  
Tropical Ecosystems ◽  
Social Bees ◽  
Bee Colony ◽  
Chemical Profiles ◽  
Land Use Practices

Stingless bees (Meliponini) are highly social bees that are native to tropical and sub-tropical ecosystems. Resin use is vital to many aspects of stingless bee colony function. Stingless bees use resin to build essential nest structures, repel predators, and kill would-be invaders. Furthermore, resin-derived compounds have been found to enrich the cuticular chemical profiles of many stingless bee species, and resin may play an important role in shaping the microbial communities associated with stingless bees and their nests. Despite its importance for colony function, previous reviews of resin use by stingless bees are lacking. This topic grows increasingly urgent as changes in beekeeping and land use practices occur, potentially diminishing stingless bees’ ability to incorporate resin into the nest environment. In this article, we review existing literature on resin use by stingless bees and discuss potential areas of future research.

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