scholarly journals Choanoflagellates and the ancestry of neurosecretory vesicles

2020 ◽  
Author(s):  
Ronja Göhde ◽  
Benjamin Naumann ◽  
Davis Laundon ◽  
Cordelia Imig ◽  
Kent McDonald ◽  
...  
Keyword(s):  
Cell Signalling ◽  
Protein Composition ◽  
Evolutionary Origin ◽  
Secretory Cells ◽  
Origin And Evolution ◽  
Basal Pole ◽  
Molecular Machinery ◽  
Unicellular Organisms ◽  
Salpingoeca Rosetta ◽  
Metazoan Cell

SummaryNeurosecretory vesicles are highly specialized trafficking organelles important for metazoan cell-cell signalling. Despite the high anatomical and functional diversity of neurons in metazoans, the protein composition of neurosecretory vesicles in bilaterians appears to be similar. This similarity points towards a common evolutionary origin. Moreover, many key neurosecretory vesicle proteins predate the origin of the first neurons and some even the origin of the first animals (metazoans). However, little is known about the molecular toolkit of these vesicles in non-bilaterian metazoans and their closest unicellular relatives, making inferences about the evolutionary origin of neurosecretory vesicles extremely difficult. By comparing 28 proteins of the core neurosecretory vesicle proteome in 13 different species, we demonstrate that most of the proteins are already present in unicellular organisms. Surprisingly, we find that the vesicle residing SNARE protein synaptobrevin is localized to the vesicle-rich apical and basal pole in the choanoflagellate Salpingoeca rosetta. Our 3D vesicle reconstructions reveal that the choanoflagellates Salpingoeca rosetta and Monosiga brevicollis exhibit a polarized and diverse vesicular landscape. This study sheds light on the ancestral molecular machinery of neurosecretory vesicles and provides a framework to understand the origin and evolution of secretory cells, synapses, and neurons.

scholarly journals Choanoflagellates and the ancestry of neurosecretory vesicles

2021 ◽  
Vol 376 (1821) ◽  
pp. 20190759 ◽  
Author(s):  
Ronja Göhde ◽  
Benjamin Naumann ◽  
Davis Laundon ◽  
Cordelia Imig ◽  
Kent McDonald ◽  
...  
Keyword(s):  
Animal Cell ◽  
Cell Signalling ◽  
Protein Composition ◽  
Synaptic Cleft ◽  
Evolutionary Origin ◽  
Receptor Protein ◽  
Secretory Cells ◽  
Origin And Evolution ◽  
Protein Receptor ◽  
Salpingoeca Rosetta

Neurosecretory vesicles are highly specialized trafficking organelles that store neurotransmitters that are released at presynaptic nerve endings and are, therefore, important for animal cell–cell signalling. Despite considerable anatomical and functional diversity of neurons in animals, the protein composition of neurosecretory vesicles in bilaterians appears to be similar. This similarity points towards a common evolutionary origin. Moreover, many putative homologues of key neurosecretory vesicle proteins predate the origin of the first neurons, and some even the origin of the first animals. However, little is known about the molecular toolkit of these vesicles in non-bilaterian animals and their closest unicellular relatives, making inferences about the evolutionary origin of neurosecretory vesicles extremely difficult. By comparing 28 proteins of the core neurosecretory vesicle proteome in 13 different species, we demonstrate that most of the proteins are present in unicellular organisms. Surprisingly, we find that the vesicular membrane-associated soluble N-ethylmaleimide-sensitive factor attachment protein receptor protein synaptobrevin is localized to the vesicle-rich apical and basal pole in the choanoflagellate Salpingoeca rosetta. Our 3D vesicle reconstructions reveal that the choanoflagellates S. rosetta and Monosiga brevicollis exhibit a polarized and diverse vesicular landscape reminiscent of the polarized organization of chemical synapses that secrete the content of neurosecretory vesicles into the synaptic cleft. This study sheds light on the ancestral molecular machinery of neurosecretory vesicles and provides a framework to understand the origin and evolution of secretory cells, synapses and neurons. This article is part of the theme issue ‘Basal cognition: multicellularity, neurons and the cognitive lens’.

scholarly journals Expanding magnetic organelle biogenesis in the domain Bacteria

Microbiome ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Wei Lin ◽  
Wensi Zhang ◽  
Greig A. Paterson ◽  
Qiyun Zhu ◽  
Xiang Zhao ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Biological Significance ◽  
Gene Clusters ◽  
Magnetic Sensors ◽  
Evolutionary Origin ◽  
Phylogenomic Analysis ◽  
Organelle Biogenesis ◽  
Taxonomic Distribution ◽  
Origin And Evolution ◽  
Bacterial Phyla

Abstract Background The discovery of membrane-enclosed, metabolically functional organelles in Bacteria has transformed our understanding of the subcellular complexity of prokaryotic cells. Biomineralization of magnetic nanoparticles within magnetosomes by magnetotactic bacteria (MTB) is a fascinating example of prokaryotic organelles. Magnetosomes, as nano-sized magnetic sensors in MTB, facilitate cell navigation along the local geomagnetic field, a behaviour referred to as magnetotaxis or microbial magnetoreception. Recent discovery of novel MTB outside the traditionally recognized taxonomic lineages suggests that MTB diversity across the domain Bacteria are considerably underestimated, which limits understanding of the taxonomic distribution and evolutionary origin of magnetosome organelle biogenesis. Results Here, we perform the most comprehensive metagenomic analysis available of MTB communities and reconstruct metagenome-assembled MTB genomes from diverse ecosystems. Discovery of MTB in acidic peatland soils suggests widespread MTB occurrence in waterlogged soils in addition to subaqueous sediments and water bodies. A total of 168 MTB draft genomes have been reconstructed, which represent nearly a 3-fold increase over the number currently available and more than double the known MTB species at the genome level. Phylogenomic analysis reveals that these genomes belong to 13 Bacterial phyla, six of which were previously not known to include MTB. These findings indicate a much wider taxonomic distribution of magnetosome organelle biogenesis across the domain Bacteria than previously thought. Comparative genome analysis reveals a vast diversity of magnetosome gene clusters involved in magnetosomal biogenesis in terms of gene content and synteny residing in distinct taxonomic lineages. Phylogenetic analyses of core magnetosome proteins in this largest available and taxonomically diverse dataset support an unexpectedly early evolutionary origin of magnetosome biomineralization, likely ancestral to the origin of the domain Bacteria. Conclusions These findings expand the taxonomic and phylogenetic diversity of MTB across the domain Bacteria and shed new light on the origin and evolution of microbial magnetoreception. Potential biogenesis of the magnetosome organelle in the close descendants of the last bacterial common ancestor has important implications for our understanding of the evolutionary history of bacterial cellular complexity and emphasizes the biological significance of the magnetosome organelle.

scholarly journals Apoptosis in Trypanosomatids: Evolutionary and phylogenetic considerations

1998 ◽  
Vol 21 (1) ◽  
pp. 21-24 ◽  
Author(s):  
Marcello A. Barcinski
Keyword(s):  
Cell Death ◽  
Normal Tissue ◽  
Evolutionary Origin ◽  
Mammalian Host ◽  
Insect Vector ◽  
Developmental Program ◽  
Unicellular Organisms ◽  
Multicellular Organisms ◽  
Organizational Needs ◽  
Experimental Strategies

Programmed cell death (PCD) or apoptosis, an active process of cell death, plays a central role in normal tissue development and organogenesis, as well as in the pathogenesis of different diseases. Although it occurs in diverse cells and tissues under the influence of a remarkable variety of inducing agents, the resultant ultrastructural and biochemical changes are extremely monotonous, indicating the existence of a common biological mechanism underlying its occurrence. It is generally accepted that a developmental program leading to cell death cannot be advantageous to unicellular organisms and that PCD appeared in evolution to fulfill the organizational needs of multicellular life. However, the recent description of apoptotic death occurring in three different species of pathogenic kinetoplastids suggests that the evolutionary origin of PCD precedes the appearence of multicellular organisms. The present study proposes that a population of pathogenic Trypanosomatids is socially organized and that PCD is a prerequisite for this organization and for the fulfillment of the demands of a heteroxenic lifestyle. This proposal includes possible roles for PCD in the development of the parasite in the insect vector and/or in its mammalian host and suggests experimental strategies to localize the evolutionary origin of PCD within the kinetoplastids.

scholarly journals The peptide pheromone-inducible conjugation system of Enterococcus faecalis plasmid pCF10: cell–cell signalling, gene transfer, complexity and evolution

2007 ◽  
Vol 362 (1483) ◽  
pp. 1185-1193 ◽  
Author(s):  
Gary M Dunny
Keyword(s):  
Cell Signalling ◽  
Cell Communication ◽  
Large Set ◽  
Conjugation System ◽  
Molecular Events ◽  
Donor Cells ◽  
Molecular Machinery ◽  
Bacterial Model ◽  
Inducible Genes ◽  
Cell Cell

Expression of a large set of gene products required for conjugative transfer of the antibiotic resistance plasmid pCF10 is controlled by cell–cell communication between plasmid-free recipient cells and plasmid-carrying donor cells using a peptide mating pheromone cCF10. Most of the recent experimental analysis of this system has focused on the molecular events involved in initiation of the pheromone response in the donor cells, and on the mechanisms by which the donor cells control self-induction by endogenously produced pheromone. Recently, studies of the molecular machinery of conjugation encoded by the pheromone-inducible genes have been initiated. In addition, the system may serve as a useful bacterial model for addressing the evolution of biological complexity.

scholarly journals Differential proteomic analysis of laser-microdissected penetration glands of avian schistosome cercariae with a focus on proteins involved in host invasion

2021 ◽  
Author(s):  
Oldřich Vondráček ◽  
Libor Mikeš ◽  
Pavel Talacko ◽  
Roman Leontovyč ◽  
Jana Bulantová ◽  
...  
Keyword(s):  
Protein Composition ◽  
Sample Volume ◽  
Secretory Cells ◽  
List Type ◽  
Supplementary Data ◽  
Sample Collection ◽  
Penetration Gland ◽  
Data Files ◽  
Venom Allergen

AbstractSchistosome invasive stages, cercariae, leave intermediate snail hosts, penetrate the skin of definitive hosts, and transform to schistosomula migrating to final localization. During invasion, cercariae employ histolytic and other bioactive products of specialized holocrine secretory cells – postacetabular (PA) and circumacetabular (CA) penetration glands. Although several studies attempted to characterize protein composition of the in vitro induced gland secretions in Schistosoma mansoni and Schistosoma japonicum, the results were inconsistent and dependent on the method of sample collection and processing. Products of both gland types mixed during their secretion did not allow localization of identified proteins to a particular gland. Here we compared proteomes of separately isolated cercarial gland cells of the avian schistosome Trichobilharzia szidati employing laser-assisted microdissection and shotgun LC-MS/MS, thus obtaining the largest dataset so far concerning the representation and localization of cercarial penetration gland proteins. We optimized the methods of sample processing with cercarial bodies (heads) first. Alizarin-pre-stained, chemically non-fixed samples provided optimal results of MS analyses, and enabled distinguishing PA and CA glands for microdissection. Using 7.5 × 106 μm3 sample volume per gland replicate, we identified 3347 peptides assigned to 792 proteins, from which 461 occurred in at least 2 of 3 replicates in either gland type (PA = 455, 40 exclusives; CA = 421, 6 exclusives; 60 proteins differed significantly in their abundance between the glands). Peptidases of 5 catalytic types accounted for ca. 8 % and 6 % of reliably identified proteins in PA and CA glands, respectively. Invadolysin, nardilysin, cathepsins B2 and L3, and elastase 2b orthologs were the major gland endopeptidases. Two cystatins and a serpin were highly abundant peptidase inhibitors in the glands. CA glands were rich in venom allergen-like proteins. The assembled total cercarial body proteome included 1631 identified proteins and revealed additional interesting factors possibly related to tissue invasion.HighlightsProteomes of two penetration gland types in schistosome cercariae greatly differPostacetabular glands possess 40 unique proteins and are abundant in hydrolasesCircumacetabular glands posses 6 unique proteins and are rich in VAL proteinsPeptidases make up 8 % of postacetabular and 6 % of circumacetabular gland proteinsCercarial elastase is unique to circumacetabular glands of Trichobilharzia szidatiNote: Supplementary data associated with this article All supplementary data files can be accessed from the following link: http://www.helminthology.cz/supplementary_files.html

scholarly journals Comparative proteomics of octocoral and scleractinian skeletomes and the evolution of coral calcification

2019 ◽  
Author(s):  
Nicola Conci ◽  
Martin Lehmann ◽  
Sergio Vargas ◽  
Gert Wörheide
Keyword(s):  
Calcium Carbonate ◽  
Three Dimensional ◽  
Comparative Proteomics ◽  
Dimensional Structure ◽  
Origin And Evolution ◽  
Core Set ◽  
Molecular Machinery ◽  
Acidic Proteins ◽  
New Research ◽  
Rigid Skeleton

AbstractCorals are ecosystem engineers of the coral reefs, one of the most biodiverse but severely threatened marine ecosystems. The ability of corals to form the three dimensional structure of reefs depends on the precipitation of calcium carbonate under biologically control. However, the exact mechanisms underlying this biologically controlled biomineralization remain to be fully unelucidated, for example whether corals employ a different molecular machinery for the deposition of different calcium carbonate (CaCO3) polymorphs (i.e., aragonite or calcite). Here we used tandem mass spectrometry (MS/MS) to compare skeletogenic proteins, i.e., the proteins occluded in the skeleton of three octocoral and one scleractinian species: Tubipora musica and Sinularia cf. cruciata, both forming calcite sclerites, the blue coral Heliopora coerulea with an aragonitic rigid skeleton, and the scleractinian aragonitic Montipora digitata. We observed extremely low overlap between aragonitic and calcitic species, while a core set of proteins is shared between octocorals producing calcite sclerites. However, the same carbonic anhydrase (CruCA4) is employed for the formation of skeletons of both polymorphs. Similarities could also be observed between octocorals and scleractinians, including the presence of a galaxin-like protein. Additionally, as in scleractinians, some octocoral skeletogenic proteins, such as acidic proteins and scleritin, appear to have been secondarily co-opted for calcification and likely derive from proteins playing different extracellular functions. In H. coerulea, co-option was characterized by aspartic acid-enrichment of proteins. This work represents the first attempt to identify the molecular basis underlying coral skeleton polymorph diversity, providing several new research targets and enabling both future functional and evolutionary studies aimed at elucidating the origin and evolution of biomineralization in corals.

scholarly journals Coevolutionary and phylogenetic analysis of Mimiviral replication machinery suggest the cellular origin of Mimiviruses

2021 ◽  
Author(s):  
Supriya Patil ◽  
Kiran Kondabagil
Keyword(s):  
Phylogenetic Analysis ◽  
Large Fraction ◽  
Purifying Selection ◽  
Replication Proteins ◽  
Replication Machinery ◽  
Origin And Evolution ◽  
Cellular Origin ◽  
Clamp Loaders ◽  
Eukaryotic Origin ◽  
Unicellular Organisms

Abstract Mimivirus is one of the most complex and largest viruses known. The origin and evolution of Mimivirus and other giant viruses have been a subject of intense study in the last two decades. The two prevailing hypotheses on the origin of Mimivirus and other viruses are the reduction hypothesis, which posits that viruses emerged from modern unicellular organisms; whereas the virus-first hypothesis proposes viruses as relics of pre-cellular forms of life. In this study, to gain insights into the origin of Mimivirus, we have carried out extensive phylogenetic, correlation, and MultiDimensional Scaling (MDS) analyses of the putative proteins involved in the replication of its 1.2-Mb large genome. Correlation analysis and MDS methods were validated using bacteriophage, bacteria, archaea, and eukaryotic replication proteins before applying to Mimivirus. We show that a large fraction of mimiviral replication proteins, including polymerase B, clamp, and clamp loaders are of eukaryotic origin and are coevolving. Although phylogenetic analysis places some components along the lineages of phage and bacteria, we show that all the replication-related genes have been homogenized and are under purifying selection. Collectively our analysis supports the idea that Mimivirus originated from a complex cellular ancestor. We hypothesize that Mimivirus has largely retained complex replication machinery reminiscent of its progenitor while losing most of the other genes related to processes such as metabolism and translation.

scholarly journals Phenotypic variability in unicellular organisms: from calcium signalling to social behaviour

2015 ◽  
Vol 282 (1819) ◽  
pp. 20152322 ◽  
Author(s):  
David Vogel ◽  
Stamatios C. Nicolis ◽  
Alfonso Perez-Escudero ◽  
Vidyanand Nanjundiah ◽  
David J. T. Sumpter ◽  
...  
Keyword(s):  
Social Interactions ◽  
Phenotypic Variability ◽  
Cell Signalling ◽  
Calcium Signalling ◽  
Social Strategies ◽  
Unicellular Organism ◽  
Unicellular Organisms ◽  
Behavioural Phenotypes ◽  
The Mean ◽  
Living Organisms

Historically, research has focused on the mean and often neglected the variance. However, variability in nature is observable at all scales: among cells within an individual, among individuals within a population and among populations within a species. A fundamental quest in biology now is to find the mechanisms that underlie variability. Here, we investigated behavioural variability in a unique unicellular organism, Physarum polycephalum . We combined experiments and models to show that variability in cell signalling contributes to major differences in behaviour underpinning some aspects of social interactions. First, following thousands of cells under various contexts, we identified distinct behavioural phenotypes: ‘slow–regular–social’, ‘fast–regular–social’ and ‘fast–irregular–asocial’. Second, coupling chemical analysis and behavioural assays we found that calcium signalling is responsible for these behavioural phenotypes. Finally, we show that differences in signalling and behaviour led to alternative social strategies. Our results have considerable implications for our understanding of the emergence of variability in living organisms.

scholarly journals The Mandibular and Hyoid Arches—From Molecular Patterning to Shaping Bone and Cartilage

2021 ◽  
Vol 22 (14) ◽  
pp. 7529
Author(s):  
Jaroslav Fabik ◽  
Viktorie Psutkova ◽  
Ondrej Machon
Keyword(s):  
Transcription Factors ◽  
Gene Regulatory Networks ◽  
Regulatory Networks ◽  
Cell Signalling ◽  
Facial Skeleton ◽  
Pharyngeal Arches ◽  
Molecular Patterning ◽  
Molecular Machinery ◽  
Gene Regulatory ◽  
And Cartilage

The mandibular and hyoid arches collectively make up the facial skeleton, also known as the viscerocranium. Although all three germ layers come together to assemble the pharyngeal arches, the majority of tissue within viscerocranial skeletal components differentiates from the neural crest. Since nearly one third of all birth defects in humans affect the craniofacial region, it is important to understand how signalling pathways and transcription factors govern the embryogenesis and skeletogenesis of the viscerocranium. This review focuses on mouse and zebrafish models of craniofacial development. We highlight gene regulatory networks directing the patterning and osteochondrogenesis of the mandibular and hyoid arches that are actually conserved among all gnathostomes. The first part of this review describes the anatomy and development of mandibular and hyoid arches in both species. The second part analyses cell signalling and transcription factors that ensure the specificity of individual structures along the anatomical axes. The third part discusses the genes and molecules that control the formation of bone and cartilage within mandibular and hyoid arches and how dysregulation of molecular signalling influences the development of skeletal components of the viscerocranium. In conclusion, we notice that mandibular malformations in humans and mice often co-occur with hyoid malformations and pinpoint the similar molecular machinery controlling the development of mandibular and hyoid arches.

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