scholarly journals Chemoreceptor diversity in apoid wasps and its reduction during the evolution of the pollen-collecting lifestyle of bees (Hymenoptera: Apoidea)

2021 ◽  
Author(s):  
George F Obiero ◽  
Thomas Pauli ◽  
Elzemiek Geuverink ◽  
René Veenendaal ◽  
Oliver Niehuis ◽  
...  
Keyword(s):  
Gene Diversity ◽  
Food Sources ◽  
Last Common Ancestor ◽  
Ampulex Compressa ◽  
Genes Encoding ◽  
Stem Lineage ◽  
Paraphyletic Group ◽  
Or Gene ◽  
Cerceris Arenaria ◽  
Or Genes

Abstract Chemoreceptors help insects to interact with their environment, to detect and assess food sources and oviposition sites, and to aid in intra- and inter-specific communication. In Hymenoptera, species of eusocial lineages possess large chemoreceptor gene repertoires compared to solitary species, possibly because of their additional need to recognize nest-mates and caste. However, a critical piece of information missing so far has been the size of chemoreceptor gene repertoires of solitary apoid wasps. Apoid wasps are a paraphyletic group of almost exclusively solitary Hymenoptera phylogenetically positioned between ant and bee, both of which include eusocial species. We report the chemosensory-related gene (CRG) repertoire sizes of three apoid wasps: Ampulex compressa, Cerceris arenaria, and Psenulus fuscipennis. We annotated genes encoding odorant (ORs), gustatory (GRs), and ionotropic (IRs) receptors and chemosensory soluble proteins (CSPs) and odorant-binding proteins (OBPs) in transcriptomes of chemosensory tissues of the above three species and in early draft genomes of two species, A. compressa and C. arenaria. Our analyses revealed that apoid wasps possess larger OR repertoires than any bee lineage, that the last common ancestor of Apoidea possessed a considerably larger OR repertoire (ca. 160) than previously estimated (73), and that the expansion of OR genes in eusocial bees was less extensive than previously assumed. Intriguingly, the evolution of pollen-collecting behavior in the stem lineage of bees was associated with a notable loss of OR gene diversity. Thus, our results support the view that herbivorous Hymenoptera tend to possess smaller OR repertoires than carnivorous, parasitoid, or kleptoparasitic species.

scholarly journals InsectOR – webserver for sensitive identification of insect olfactory receptor genes from non-model genomes

2020 ◽  
Author(s):  
Snehal D. Karpe ◽  
Vikas Tiwari ◽  
Sowdhamini Ramanathan
Keyword(s):  
Genome Annotation ◽  
Gene Prediction ◽  
Web Server ◽  
Olfactory Receptors ◽  
Rapid Prediction ◽  
Protein Receptors ◽  
Olfactory Receptor Genes ◽  
Or Gene ◽  
Or Genes ◽  
The Web

AbstractInsect Olfactory Receptors (ORs) are diverse family of membrane protein receptors responsible for most of the insect olfactory perception and communication, and hence they are of utmost importance for developing repellents or pesticides. Hence, accurate gene prediction of insect ORs from newly sequenced genomes is an important but challenging task. We have developed a dedicated web-server, ‘insectOR’, to predict and validate insect OR genes using multiple gene prediction algorithms, accompanied by relevant validations. It is possible to employ this sever nearly automatically and perform rapid prediction of the OR gene loci from thousands of OR-protein-to-genome alignments, resolve gene boundaries for tandem OR genes and refine them further to provide more complete OR gene models. InsectOR outperformed the popular genome annotation pipelines (MAKER and NCBI eukaryotic genome annotation) in terms of overall sensitivity at base, exon and locus level, when tested on two distantly related insect genomes. It displayed more than 95% nucleotide level precision in both tests. Finally, given the same input data and parameters, InsectOR missed less than 2% gene loci, in contrast to 55% loci missed by MAKER for Drosophila melanogaster. The web-server is freely available on the web at http://caps.ncbs.res.in/insectOR/. All major browsers are supported. Website is implemented in Python with Jinja2 for templating and bootstrap framework which uses HTML, CSS and JavaScript/Ajax. The core pipeline is written in Perl.

Gene Differentiation in Pacific Salmon (Oncorhynchus sp.): Facts and Models with Reference to Pink Salmon (O. gorbuscha)

1994 ◽  
Vol 51 (S1) ◽  
pp. 223-232 ◽  
Author(s):  
Lev A. Zhivotovsky ◽  
A. J. Gharrett ◽  
A. J. McGregor ◽  
M. K. Glubokovsky ◽  
Marcus W. Feldman
Keyword(s):  
Pacific Salmon ◽  
Gene Diversity ◽  
Genetic Relationships ◽  
Pink Salmon ◽  
Theoretical Models ◽  
Genetic Distances ◽  
Gene Drift ◽  
Gene Differentiation ◽  
Or Gene ◽  
And Migration

Analyzing population genetic data usually involves examining relationships among populations followed by analysis of the distribution of genetic variability. Genetic relationships are often depicted with multidimensional scaling or trees constructed from genetic distances; genetic variation within and among populations is partitioned using gene diversity measures such as FST or GST. Genetic distances or gene diversity are often used to estimate influences of gene drift, migration, and/or selection on observed gene differentiation. We used allozyme data for pink salmon populations to examine the theoretical models available for estimating magnitudes of these factors in Pacific salmon populations. The models included (1) mutation and gene drift; (2) mutation and migration; (3) migration and gene drift; and (4) gene drift, migration, and selection. These models suggest that gene drift and migration are probably important at the lowest levels of population hierarchy, but even very small forces such as weak heterogeneous selection and low migration levels may be important at higher levels. The accuracy of some estimates should be questioned because for many situations appropriate models are either not yet available or are not sufficiently refined. Also, the dynamic genetic structure of salmon populations makes it unlikely that the steady state assumed for many theoretical models has obtained.

scholarly journals MHC-Linked Olfactory Receptor Loci Exhibit Polymorphism and Contribute to Extended HLA/OR-Haplotypes

2000 ◽  
Vol 10 (12) ◽  
pp. 1968-1978 ◽  
Author(s):  
Anke Ehlers ◽  
Stephan Beck ◽  
Simon A. Forbes ◽  
John Trowsdale ◽  
Armin Volz ◽  
...  
Keyword(s):  
Olfactory Receptor ◽  
Sequence Data ◽  
Allelic Variation ◽  
Mate Preferences ◽  
Coding Region ◽  
Link Type ◽  
Or Gene ◽  
Hla Haplotypes ◽  
A Minor ◽  
Or Genes

Clusters of olfactory receptor (OR) genes are found on most human chromosomes. They are one of the largest mammalian multigene families. Here, we report a systematic study of polymorphism of OR genes belonging to the largest fully sequenced OR cluster. The cluster contains 36 OR genes, of which two belong to the vomeronasal 1 (V1-OR) family. The cluster is divided into a major and a minor region at the telomeric end of the HLA complex on chromosome 6. These OR genes could be involved in MHC-related mate preferences. The polymorphism screen was carried out with 13 genes from the HLA-linked OR cluster and three genes from chromosomes 7, 17, and 19 as controls. Ten human cell lines, representing 18 different chromosome 6s, were analyzed. They were from various ethnic origins and exhibited different HLA haplotypes. All OR genes tested, including those not linked to the HLA complex, were polymorphic. These polymorphisms were dispersed along the coding region and resulted in up to seven alleles for a given OR gene. Three polymorphisms resulted either in stop codons (genes hs6M1-4P,hs6M1-17) or in a 16–bp deletion (gene hs6M1-19P), possibly leading to lack of ligand recognition by the respective receptors in the cell line donors. In total, 13 HLA-linked OR haplotypes could be defined. Therefore, allelic variation appears to be a general feature of human OR genes.[The sequence data reported in this paper have been submitted to EMBL under accession nos. AC006137, AC004178, AJ132194, AL022727, AL031983,AL035402, AL035542, Z98744, CAB55431, AL050339, AL035402, AL096770,AL133267, AL121944, Z98745, AL021808, and AL021807.]

LisRK is required for optimal fitness of Listeria monocytogenes in soil

2020 ◽  
Vol 367 (22) ◽  
Author(s):  
Maja Z Brunhede ◽  
Patrícia T Dos Santos ◽  
Laurent Gal ◽  
Dominique Garmyn ◽  
Birgitte H Kallipolitis ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Soil Environment ◽  
Sterile Soil ◽  
Natural Habitats ◽  
Growth And Survival ◽  
Food Borne ◽  
Mutant Strains ◽  
Genes Encoding ◽  
Two Component Systems ◽  
Or Genes

ABSTRACT Listeria monocytogenes is a food-borne pathogen responsible for the disease listeriosis. It is ubiquitously found in the environment and soil is one of its natural habitats. Listeria monocytogenes is highly capable of coping with various stressful conditions. We hypothesized that stress-responsive two-component systems such as LisRK might contribute to the adaptation of L. monocytogenes to the soil environment. Indeed, investigations of the population dynamics of wild-type and mutant strains suggest an important role of LisRK for optimal fitness of L. monocytogenes in sterile soil. Results from non-sterile soil showed that the parental strain was capable of surviving longer than mutant strains lacking lisRK or genes encoding the LisRK-regulated LhrC small RNAs (sRNAs), suggesting that LisRK as well as the LhrC sRNAs were important for survival. Transcription of five LisRK-regulated genes was assessed after 1 h incubation in sterile soil. We observed that LisRK and the LhrC sRNAs contribute to the upregulation of lmo2522 in the soil environment. Notably, lmo2522 encodes an equivalent of the resuscitation promoting factors, Rpfs, in actinobacteria. Collectively, our study demonstrates that LisRK is important for growth and survival in sterile and non-sterile soil and suggests a role for LisRK-regulation of Lmo2522 in resuscitation from dormancy in the soil environment.

scholarly journals Bioinformatics Discovery of Putative Enhancers within Mouse Odorant Receptor Gene Clusters

2019 ◽  
Vol 44 (9) ◽  
pp. 705-720
Author(s):  
James E Farber ◽  
Robert P Lane
Keyword(s):  
Odorant Receptor ◽  
Receptor Gene ◽  
Gene Clusters ◽  
Small Subset ◽  
Histone 3 ◽  
Large Size ◽  
Dnase Hypersensitivity ◽  
Or Gene ◽  
Or Genes ◽  
Flanking Regions

Abstract Olfactory neuronal function depends on the expression and proper regulation of odorant receptor (OR) genes. Previous studies have identified 54 putative intergenic enhancers within or flanking 40 mouse OR clusters. At least 2 of these putative enhancers have been shown to regulate the expression of a small subset of proximal OR genes. In recognition of the large size of the mouse OR gene family (~1400 OR genes distributed across multiple chromosomal loci), it is likely that there remain many additional not-as-yet discovered OR enhancers. We utilized 23 of the previously identified enhancers as a training set (TS) and designed an algorithm that combines a broad range of epigenetic criteria (histone-3-lysine-4 monomethylation, histone-3-lysine-79 trimethylation, histone-3-lysine-27 acetylation, and DNase hypersensitivity) and genetic criteria (cross-species sequence conservation and transcription-factor binding site enrichment) to more broadly search OR gene clusters for additional candidates. We identified 181 new candidate enhancers located at 58 (of 68) mouse OR loci, including 25 new candidates identified by stringent search criteria whose signal strengths are not significantly different from the 23 previously characterized OR enhancers used as the TS. Additionally, we compared OR enhancer versus generic enhancer features in order to evaluate likelihoods that new enhancer candidates specifically function in OR regulation. We found that features distinguishing OR-specific function are significantly more evident for enhancer candidates located within OR clusters as compared with those in flanking regions.

scholarly journals Control of chitin and N-acetylglucosamine utilization in Saccharopolyspora erythraea

Microbiology ◽  
2014 ◽  
Vol 160 (9) ◽  
pp. 1914-1928 ◽  
Author(s):  
Chengheng Liao ◽  
Sébastien Rigali ◽  
Cuauhtemoc Licona Cassani ◽  
Esteban Marcellin ◽  
Lars Keld Nielsen ◽  
...  
Keyword(s):  
Transcriptional Control ◽  
Streptomyces Coelicolor ◽  
Saccharopolyspora Erythraea ◽  
Phosphotransferase System ◽  
Nutrient Source ◽  
Intracellular Degradation ◽  
Rare Actinomycetes ◽  
Genes Encoding ◽  
Or Genes ◽  
Model Strain

Chitin degradation and subsequent N-acetylglucosamine (GlcNAc) catabolism is thought to be a common trait of a large majority of actinomycetes. Utilization of aminosugars had been poorly investigated outside the model strain Streptomyces coelicolor A3(2), and we examined here the genetic setting of the erythromycin producer Saccharopolyspora erythraea for GlcNAc and chitin utilization, as well as the transcriptional control thereof. Sacch. erythraea efficiently utilize GlcNAc most likely via the phosphotransferase system (PTSGlcNAc); however, this strain is not able to grow when chitin or N,N′-diacetylchitobiose [(GlcNAc)2] is the sole nutrient source, despite a predicted extensive chitinolytic system (chi genes). The inability of Sacch. erythraea to utilize chitin and (GlcNAc)2 is probably because of the loss of genes encoding the DasABC transporter for (GlcNAc)2 import, and genes for intracellular degradation of (GlcNAc)2 by β-N-acetylglucosaminidases. Transcription analyses revealed that in Sacch. erythraea all putative chi and GlcNAc utilization genes are repressed by DasR, whereas in Strep. coelicolor DasR displayed either activating or repressing functions whether it targets genes involved in the polymer degradation or genes for GlcNAc dimer and monomer utilization, respectively. A transcriptomic analysis further showed that GlcNAc not only activates the transcription of GlcNAc catabolism genes but also activates chi gene expression, as opposed to the previously reported GlcNAc-mediated catabolite repression in Strep. coelicolor. Finally, synteny exploration revealed an identical genetic background for chitin utilization in other rare actinomycetes, which suggests that screening procedures that used only the chitin-based protocol for selective isolation of antibiotic-producing actinomycetes could have missed the isolation of many industrially promising strains.

Evolution of biosynthetic diversity

2017 ◽  
Vol 474 (14) ◽  
pp. 2277-2299 ◽  
Author(s):  
Anthony J. Michael
Keyword(s):  
Common Ancestor ◽  
Polyamine Metabolism ◽  
Last Common Ancestor ◽  
Protein Fold ◽  
Last Universal Common Ancestor ◽  
Endosymbiotic Gene Transfer ◽  
Evolutionary Mechanisms ◽  
Universal Common Ancestor ◽  
Genes Encoding ◽  
Domains Of Life

Since the emergence of the last common ancestor from which all extant life evolved, the metabolite repertoire of cells has increased and diversified. Not only has the metabolite cosmos expanded, but the ways in which the same metabolites are made have diversified. Enzymes catalyzing the same reaction have evolved independently from different protein folds; the same protein fold can produce enzymes recognizing different substrates, and enzymes performing different chemistries. Genes encoding useful enzymes can be transferred between organisms and even between the major domains of life. Organisms that live in metabolite-rich environments sometimes lose the pathways that produce those same metabolites. Fusion of different protein domains results in enzymes with novel properties. This review will consider the major evolutionary mechanisms that generate biosynthetic diversity: gene duplication (and gene loss), horizontal and endosymbiotic gene transfer, and gene fusion. It will also discuss mechanisms that lead to convergence as well as divergence. To illustrate these mechanisms, one of the original metabolisms present in the last universal common ancestor will be employed: polyamine metabolism, which is essential for the growth and cell proliferation of archaea and eukaryotes, and many bacteria.

scholarly journals Analysis of genes of tetrahydrofolate-dependent metabolism from cultivated spirochaetes and the gut community of the termite Zootermopsis angusticollis

Microbiology ◽  
2003 ◽  
Vol 149 (9) ◽  
pp. 2529-2537 ◽  
Author(s):  
Tina M. Salmassi ◽  
Jared R. Leadbetter
Keyword(s):  
Gene Diversity ◽  
Homologous Proteins ◽  
Bacterial Phyla ◽  
Zootermopsis Angusticollis ◽  
Termite Gut ◽  
Genes Encoding ◽  
Methylenetetrahydrofolate Dehydrogenase ◽  
Key Enzyme ◽  
Pure Cultures ◽  
Novel Taxa

The hindguts of wood-feeding termites are the sites of intense, CO2-reductive acetogenesis. This activity profoundly influences host nutrition and methane emissions. Homoacetogens previously isolated from diverse termites comprised novel taxa belonging to two distinct bacterial phyla, Firmicutes and Spirochaetes. Little else is known about either the diversity or abundance of homoacetogenic species present in any given termite or the genetic details underlying CO2-reductive acetogenesis by Spirochaetes. A key enzyme of CO2-reductive acetogenesis is formyltetrahydrofolate synthetase (FTHFS). A previously designed primer set was used to amplify FTHFS genes from three isolated termite-gut spirochaetes. Sequencing DNA flanking the FTHFS gene of Treponema strain ZAS-2 revealed genes encoding two acetogenesis-related enzymes, methenyltetrahydrofolate cyclohydrolase and methylenetetrahydrofolate dehydrogenase. Although termite-gut spirochaetes are only distantly related to clostridia at the ribosomal level, their tetrahydrofolate-dependent enzymes appear to be closely related. In contrast, homologous proteins identified in the non-homoacetogenic oral spirochaete Treponema denticola were only distantly related to those from clostridia and the termite-gut treponemes. Having demonstrated their utility with spirochaete pure cultures, the FTHFS primers were used to construct a 91-clone library from the termite-gut community DNA. From this, 19 DNA and eight amino acid FTHFS types were identified. Over 75 % of the retrieved clones formed a novel, coherent cluster with the FTHFS homologues obtained from the termite-gut treponemes. Thus, FTHFS gene diversity in the gut of the termite Zootermopsis angusticollis appears to be dominated by spirochaetes. The homoacetogenic capacity of termite-gut spirochaetes may have been acquired via lateral gene transfer from clostridia.

scholarly journals A Mouse with a Monoclonal Primary lmmunoglobulin Repertoire not Further Diversified by V-Gene Replacement

1999 ◽  
Vol 7 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Marilia Cascalho ◽  
Denise A. Martin ◽  
Jamie Wong ◽  
Queenie Lam ◽  
Matthias Wabl ◽  
...  
Keyword(s):  
T Cells ◽  
B Cells ◽  
B Cell ◽  
Heavy Chain ◽  
Light Chain ◽  
Gene Replacement ◽  
Genes Encoding ◽  
V Gene ◽  
Immunoglobulin Repertoire ◽  
Or Gene

We have generated a monoclonal B-cell mouse by introducing homozygous, nonfunctional RAG-2 alleles and aλ1 light-chain transgene into the quasi-monoclonal (QM) mouse, which contains a “knocked-in” VHDJHrearrangement. Thus, this mouse, which we call MonoB, is devoid of T cells and contains preformed heavy- and light-chain genes encoding immunoglobulin with an anti-NP specificity. The MonoB mouse allows us to examine immunoglobulin diversity in the absence of processes mediated by V(D)J recombination and T cells. Here we report that not only is the MonoB's primary immunoglobulin repertoire monoclonal, but also that its secondary repertoire is not further diversified by V-gene replacement or gene conversion. Among 99 heavy-chain and 41λlight-chain genes from peripheral B cells of the MonoB mouse, there were no V-gene replacements. When compared to the QM mouse, which has RAG activity, and for which V-gene replacement is the major diversifying mechanism, these data suggest that V-gene replacement is mediated by V(D)J recombination and not by other recombination systems.

scholarly journals Evidence for Cascades of Perturbation and Adaptation in the Metabolic Genes of Higher Termite Gut Symbionts

mBio ◽  
2012 ◽  
Vol 3 (4) ◽  
Author(s):  
Xinning Zhang ◽  
Jared R. Leadbetter
Keyword(s):  
Microbial Communities ◽  
Convergent Evolution ◽  
Last Common Ancestor ◽  
Evolutionary Mechanisms ◽  
Bacterial Gene ◽  
Family Patterns ◽  
Termite Gut ◽  
Genes Encoding ◽  
Gut Symbionts ◽  
Extinction Events

ABSTRACTTermites and their gut microbes engage in fascinating dietary mutualisms. Less is known about how these complex symbioses have evolved after first emerging in an insect ancestor over 120 million years ago. Here we examined a bacterial gene, formate dehydrogenase (fdhF), that is key to the mutualism in 8 species of “higher” termite (members of theTermitidae, the youngest and most biomass-abundant and species-rich termite family). Patterns offdhFdiversity in the gut communities of higher termites contrasted strongly with patterns in less-derived (more-primitive) insect relatives (wood-feeding “lower” termites and roaches). We observed phylogenetic evidence for (i) the sweeping loss of several clades offdhFthat may reflect extinctions of symbiotic protozoa and, importantly, bacteria dependent on them in the last common ancestor of all higher termites and (ii) a radiation of genes from the (possibly) single allele that survived. Sweeping gene loss also resulted in (iii) the elimination of an entire clade of genes encoding selenium (Se)-independent enzymes from higher termite gut communities, perhaps reflecting behavioral or morphological innovations in higher termites that relaxed preexisting environmental limitations of Se, a dietary trace element. Curiously, several higher termite gut communities may have subsequently reencountered Se limitation, reinventing genes for Se-independent proteins via convergent evolution. Lastly, the presence of a novelfdhFlineage within litter-feeding and subterranean higher (but not other) termites may indicate recent gene “invasion” events. These results imply that cascades of perturbation and adaptation by distinct evolutionary mechanisms have impacted the evolution of complex microbial communities in a highly successful lineage of insects.IMPORTANCESince patterns of relatedness between termite hosts are broadly mirrored by the relatedness of their symbiotic gut microbiota, coevolution between hosts and gut symbionts is rightly considered an important force that has shaped dietary mutualism since its inception over 120 million years ago. Apart from that concerning lateral gene or symbiont transfer between termite gut communities (for which no evidence yet exists), there has been little discussion of alternative mechanisms impacting the evolution of mutualism. Here we provide strong gene-based evidence for past environmental perturbations creating significant upheavals that continue to reverberate throughout the gut communities of species comprising a single termite lineage. We suggest that symbiont extinction events, sweeping gene losses, evolutionary radiations, relaxation and reemergence of key nutritional pressures, convergent evolution of similar traits, and recent gene invasions have all shaped gene composition in the symbiotic gut microbial communities of higher termites, currently the most dominant and successful termite family on Earth.

Sign in / Sign up

Export Citation Format

Share Document