scholarly journals Odorant receptor copy number change, co-expression, and positive selection establish peripheral coding differences between fly species

2021 ◽  
Author(s):  
Thomas O. Auer ◽  
Raquel Álvarez-Ocaña ◽  
Steeve Cruchet ◽  
Richard Benton ◽  
J. Roman Arguello

Animals sample their chemical environment using sensory neurons that express diverse chemosensory receptors, which trigger responses when they bind environmental molecules. In addition to modifications in the ligand binding properties of receptors, chemosensory receptor evolution is characterized by copy number changes, often resulting in large gene family size differences between species. Though chemosensory receptor expansions and contractions are frequently described, it is unknown how this is accompanied by changes in the neural circuitry in which they are expressed. Among Drosophila's chemosensory receptor families, the Odorant receptors (Ors) are ideal for addressing this question because, other than an essential co-receptor (Orco), a large majority of Ors are uniquely expressed in single olfactory sensory neuron (OSN) populations. Between-species changes in Or copy number, therefore, may indicate diversification or reduction of peripheral sensory neuron populations. To test this possibility, we focused on a rapidly duplicated/deleted Or subfamily - named Or67a - within Drosophila melanogaster and its most closely-related sister species (D. simulans, D. sechellia, and D. mauritiana). Evolutionary genetic analyses and in vivo physiological assays demonstrate that the common ancestor of these four species possessed three Or67a paralogs that had already diverged adaptively in their odor-evoked responses. Following the group's speciation events, two Or67a paralogs were independently lost in D. melanogaster and D. sechellia, with positive selection continuing to act on the intact genes. Instead of the expected singular expression of each of the functionally diverged Ors in different neurons, we found that the three D. simulans Or67a paralogs are co-expressed in the same cells. Thus, while neuroanatomy is conserved between these species, independent selection on co-expressed receptors has contributed to species-specific peripheral coding of olfactory information. This work reveals a model of adaptive change previously not considered for olfactory evolution and raises the possibility that similar processes may be operating among the largely uninvestigated cases of Or co-expression.

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3351-3351
Author(s):  
David Tamborero ◽  
Muntasir Mamun Majumder ◽  
Raija Silvennoinen ◽  
Samuli Eldfors ◽  
Pekka Anttila ◽  
...  

Abstract Introduction Multiple myeloma (MM) is a heterogeneous disease that eventually becomes resistant to therapy. Determining the genomic lesions driving each stage of the tumor and identifying actionable items for novel targeted drugs will improve and increase therapeutic options for the malignancy. The aim of the present work is to obtain a comprehensive catalog of driver genomic lesions for both newly diagnosed (NDMM) and refractory/relapsed MM (RRMM) patients by integrating multiple genomic data and linking these to the action of targeted therapeutic approaches. Methods Molecular cytogenetics was assessed by fluorescence in situ hybridization and somatic mutations and copy number changes were identified by performing exome sequencing of DNA from CD138+ cell and skin paired samples collected from 30 MM patients (NDMM n=12; RRMM n=18). In addition, gene expression profiles were obtained by transcriptome sequencing. The proportion of tumor clones bearing a specific mutation was inferred from the variant allele frequency. Genetic alterations involved in the tumorigenesis of each patient (named drivers) were identified by combining an in silico method aimed to score their potential for being malignant with the a priori knowledge retrieved from the identification of complementary signals of positive selection in available tumor cohorts (Tamborero et al. Nat Sci Rep 2013). Selective drug response was assessed by testing the ex vivo sensitivity of patient derived CD138+ cells to 306 oncology drugs and comparing results with responses derived from healthy bone marrow control cells. Results Overall, 0.5 translocations, 3±2.8 mutations and 4.9±2.7 copy number changes per patient were identified as putative drivers. The total number of driver alterations did not differ between NDMM and RRMM samples, and no gene reached statistical significance for being more frequently altered in the latter group. However, the only mutations in RAS genes that appeared at sub-clonal proportions occurred in diagnosed samples, pointing out their positive selection among relapsed patients in which they were present in all clones. Translocations involving IGH@ were observed in 11 (37%) patients, and interestingly 3 other samples exhibited driver alterations in the oncogenes involved in these fusions (i.e. activating mutations in FGFR3 or gene amplification plus peaked overexpression of WHSC1 and CCND1). Recurrent alterations were observed among genes previously associated with MM, including DIS3 (n=15), KRAS (n=11), CYLD (n=8), TRAF3 (n=6) and FAM46C (n=5). Other genes not previously associated with or less-known to be involved in MM pathogenesis were also identified, including the histone methyltransferase MLL, the tumor necrosis factor associated genes FAF1 and TNFRSF13B, the p53-suppressing protein phosphatase PPM1D, and several genes related with blood cell differentiation and B-lymphocyte development (e.g. SOX7, BLK and PRDM1). Overall, the pathways most frequently targeted by driver alterations were MAPK (23 (77%) samples, mostly by mutations), NF-κB (17(57%) samples, mostly by gene copy loss), cell-cycle (18 (60%) samples), and RNA-processing (17 (57%) samples). Comparison of driver lesions to drug response using data derived from ex vivo testing of the same patient samples to different targeted small molecule inhibitors (e.g. PI3K/mTOR and MEK inhibitors) indicated that alterations affecting PI3K and p53 pathways were associated with increased drug sensitivity, while alterations involving activation of FGFR3 and copy loss of TRAF3 were associated with a more resistant phenotype. Conclusions The integration of multiple genomic data by combining different predictive computational tools can comprehensively identify cancer events in individual patients. Applying these tools to genomic data from MM patients identified both known and novel driver lesions, and some of these alterations were associated with the ex vivo response to selective drugs. However, further data is required to confirm biomarkers of response to those novel therapeutics and test potential benefits in MM patients. Disclosures Silvennoinen: Janssen, Sanofi, Celgene: Honoraria; Research Funding of Government Finland, Research Funding from Janssen and Celgene: Research Funding. Porkka:Novartis: Honoraria, Research Funding; Bristol-Myers Squibb: Honoraria, Research Funding. Heckman:Celgene: Research Funding.


Author(s):  
М.Е. Лопаткина ◽  
В.С. Фишман ◽  
М.М. Гридина ◽  
Н.А. Скрябин ◽  
Т.В. Никитина ◽  
...  

Проведен анализ генной экспрессии в нейронах, дифференцированных из индуцированных плюрипотентных стволовых клеток пациентов с идиопатическими интеллектуальными нарушениями и реципрокными хромосомными мутациями в регионе 3p26.3, затрагивающими единственный ген CNTN6. Для нейронов с различным типом хромосомных аберраций была показана глобальная дисрегуляция генной экспрессии. В нейронах с вариациями числа копий гена CNTN6 была снижена экспрессия генов, продукты которых вовлечены в процессы развития центральной нервной системы. The gene expression analysis of iPSC-derived neurons, obtained from patients with idiopathic intellectual disability and reciprocal microdeletion and microduplication in 3p26.3 region affecting the single CNTN6 gene was performed. The global gene expression dysregulation was demonstrated for cells with CNTN6 copy number variation. Gene expression in neurons with CNTN6 copy number changes was downregulated for genes, whose products are involved in the central nervous system development.


Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 86
Author(s):  
Erin M. Garcia ◽  
Myrna G. Serrano ◽  
Laahirie Edupuganti ◽  
David J. Edwards ◽  
Gregory A. Buck ◽  
...  

Gardnerella vaginalis has recently been split into 13 distinct species. In this study, we tested the hypotheses that species-specific variations in the vaginolysin (VLY) amino acid sequence could influence the interaction between the toxin and vaginal epithelial cells and that VLY variation may be one factor that distinguishes less virulent or commensal strains from more virulent strains. This was assessed by bioinformatic analyses of publicly available Gardnerella spp. sequences and quantification of cytotoxicity and cytokine production from purified, recombinantly produced versions of VLY. After identifying conserved differences that could distinguish distinct VLY types, we analyzed metagenomic data from a cohort of female subjects from the Vaginal Human Microbiome Project to investigate whether these different VLY types exhibited any significant associations with symptoms or Gardnerella spp.-relative abundance in vaginal swab samples. While Type 1 VLY was most prevalent among the subjects and may be associated with increased reports of symptoms, subjects with Type 2 VLY dominant profiles exhibited increased relative Gardnerella spp. abundance. Our findings suggest that amino acid differences alter the interaction of VLY with vaginal keratinocytes, which may potentiate differences in bacterial vaginosis (BV) immunopathology in vivo.


Toxins ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 78
Author(s):  
Lachlan A. Bourke ◽  
Christina N. Zdenek ◽  
Edgar Neri-Castro ◽  
Melisa Bénard-Valle ◽  
Alejandro Alagón ◽  
...  

The toxin composition of snake venoms and, thus, their functional activity, can vary between and within species. Intraspecific venom variation across a species’ geographic range is a major concern for antivenom treatment of envenomations, particularly for countries like French Guiana that lack a locally produced antivenom. Bothrops asper and Bothrops atrox are the most medically significant species of snakes in Latin America, both producing a variety of clinical manifestations, including systemic bleeding. These pathophysiological actions are due to the activation by the venom of the blood clotting factors Factor X and prothrombin, thereby causing severe consumptive coagulopathy. Both species are extremely wide-ranging, and previous studies have shown their venoms to exhibit regional venom variation. In this study, we investigate the differential coagulotoxic effects on human plasma of six venoms (four B. asper and two B. atrox samples) from different geographic locations, spanning from Mexico to Peru. We assessed how the venom variation of these venom samples affects neutralisation by five regionally available antivenoms: Antivipmyn, Antivipmyn-Tri, PoliVal-ICP, Bothrofav, and Soro Antibotrópico (SAB). The results revealed both inter- and intraspecific variations in the clotting activity of the venoms. These variations in turn resulted in significant variation in antivenom efficacy against the coagulotoxic effects of these venoms. Due to variations in the venoms used in the antivenom production process, antivenoms differed in their species-specific or geographical neutralisation capacity. Some antivenoms (PoliVal-ICP, Bothrofav, and SAB) showed species-specific patterns of neutralisation, while another antivenom (Antivipmyn) showed geographic-specific patterns of neutralisation. This study adds to current knowledge of Bothrops venoms and also illustrates the importance of considering evolutionary biology when developing antivenoms. Therefore, these results have tangible, real-world implications by aiding evidence-based design of antivenoms for treatment of the envenomed patient. We stress that these in vitro studies must be backed by future in vivo studies and clinical trials before therapeutic guidelines are issued regarding specific antivenom use in a clinical setting.


2021 ◽  
Vol 22 (9) ◽  
pp. 4368
Author(s):  
Heriberto Rodriguez-Martinez ◽  
Emilio A. Martinez ◽  
Juan J. Calvete ◽  
Fernando J. Peña Vega ◽  
Jordi Roca

Seminal plasma (SP), the non-cellular component of semen, is a heterogeneous composite fluid built by secretions of the testis, the epididymis and the accessory sexual glands. Its composition, despite species-specific anatomical peculiarities, consistently contains inorganic ions, specific hormones, proteins and peptides, including cytokines and enzymes, cholesterol, DNA and RNA—the latter often protected within epididymis- or prostate-derived extracellular vesicles. It is beyond question that the SP participates in diverse aspects of sperm function pre-fertilization events. The SP also interacts with the various compartments of the tubular genital tract, triggering changes in gene function that prepares for an eventual successful pregnancy; thus, it ultimately modulates fertility. Despite these concepts, it is imperative to remember that SP-free spermatozoa (epididymal or washed ejaculated) are still fertile, so this review shall focus on the differences between the in vivo roles of the SP following semen deposition in the female and those regarding additions of SP on spermatozoa handled for artificial reproduction, including cryopreservation, from artificial insemination to in vitro fertilization. This review attempts, including our own results on model animal species, to critically summarize the current knowledge of the reproductive roles played by SP components, particularly in our own species, which is increasingly affected by infertility. The ultimate goal is to reconcile the delicate balance between the SP molecular concentration and their concerted effects after temporal exposure in vivo. We aim to appraise the functions of the SP components, their relevance as diagnostic biomarkers and their value as eventual additives to refine reproductive strategies, including biotechnologies, in livestock models and humans.


2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Peter Higgins ◽  
Cooper A Grace ◽  
Soon A Lee ◽  
Matthew R Goddard

Abstract Saccharomyces cerevisiae is extensively utilized for commercial fermentation, and is also an important biological model; however, its ecology has only recently begun to be understood. Through the use of whole-genome sequencing, the species has been characterized into a number of distinct subpopulations, defined by geographical ranges and industrial uses. Here, the whole-genome sequences of 104 New Zealand (NZ) S. cerevisiae strains, including 52 novel genomes, are analyzed alongside 450 published sequences derived from various global locations. The impact of S. cerevisiae novel range expansion into NZ was investigated and these analyses reveal the positioning of NZ strains as a subgroup to the predominantly European/wine clade. A number of genomic differences with the European group correlate with range expansion into NZ, including 18 highly enriched single-nucleotide polymorphism (SNPs) and novel Ty1/2 insertions. While it is not possible to categorically determine if any genetic differences are due to stochastic process or the operations of natural selection, we suggest that the observation of NZ-specific copy number increases of four sugar transporter genes in the HXT family may reasonably represent an adaptation in the NZ S. cerevisiae subpopulation, and this correlates with the observations of copy number changes during adaptation in small-scale experimental evolution studies.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Ruklanthi de Alwis ◽  
Li Liang ◽  
Omid Taghavian ◽  
Emma Werner ◽  
Hao Chung The ◽  
...  

Abstract Background Shigella is a major diarrheal pathogen for which there is presently no vaccine. Whole genome sequencing provides the ability to predict and derive novel antigens for use as vaccines. Here, we aimed to identify novel immunogenic Shigella antigens that could serve as Shigella vaccine candidates, either alone, or when conjugated to Shigella O-antigen. Methods Using a reverse vaccinology approach, where genomic analysis informed the Shigella immunome via an antigen microarray, we aimed to identify novel immunogenic Shigella antigens. A core genome analysis of Shigella species, pathogenic and non-pathogenic Escherichia coli, led to the selection of 234 predicted immunogenic Shigella antigens. These antigens were expressed and probed with acute and convalescent serum from microbiologically confirmed Shigella infections. Results Several Shigella antigens displayed IgG and IgA seroconversion, with no difference in sero-reactivity across by sex or age. IgG sero-reactivity to key Shigella antigens was observed at birth, indicating transplacental antibody transfer. Six antigens (FepA, EmrK, FhuA, MdtA, NlpB, and CjrA) were identified in in vivo testing as capable of producing binding IgG and complement-mediated bactericidal antibody. Conclusions These findings provide six novel immunogenic Shigella proteins that could serve as candidate vaccine antigens, species-specific carrier proteins, or targeted adjuvants.


2021 ◽  
Vol 22 (3) ◽  
pp. 1146
Author(s):  
Reinhard Ullmann ◽  
Benjamin Valentin Becker ◽  
Simone Rothmiller ◽  
Annette Schmidt ◽  
Horst Thiermann ◽  
...  

Sulfur mustard (SM) is a chemical warfare agent that can damage DNA via alkylation and oxidative stress. Because of its genotoxicity, SM is cancerogenic and the progenitor of many chemotherapeutics. Previously, we developed an SM-resistant cell line via chronic exposure of the popular keratinocyte cell line HaCaT to increasing doses of SM over a period of 40 months. In this study, we compared the genomic landscape of the SM-resistant cell line HaCaT/SM to its sensitive parental line HaCaT in order to gain insights into genetic changes associated with continuous alkylation and oxidative stress. We established chromosome numbers by cytogenetics, analyzed DNA copy number changes by means of array Comparative Genomic Hybridization (array CGH), employed the genome-wide chromosome conformation capture technique Hi-C to detect chromosomal translocations, and derived mutational signatures by whole-genome sequencing. We observed that chronic SM exposure eliminated the initially prevailing hypotetraploid cell population in favor of a hyperdiploid one, which contrasts with previous observations that link polyploidization to increased tolerance and adaptability toward genotoxic stress. Furthermore, we observed an accumulation of chromosomal translocations, frequently flanked by DNA copy number changes, which indicates a high rate of DNA double-strand breaks and their misrepair. HaCaT/SM-specific single-nucleotide variants showed enrichment of C > A and T > A transversions and a lower rate of deaminated cytosines in the CpG dinucleotide context. Given the frequent use of HaCaT in toxicology, this study provides a valuable data source with respect to the original genotype of HaCaT and the mutational signatures associated with chronic alkylation and oxidative stress.


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