scholarly journals Genomic architecture and sexually dimorphic expression underlying immunity in the red mason bee, Osmia bicornis

2021 ◽  
Author(s):  
Jannik Sven Moellmann ◽  
Thomas Joseph Colgan

Insect pollinators provide crucial ecosystem services yet face increasing environmental pressures. The challenges posed by novel and reemerging pathogens on bee health means we need to improve our understanding of the immune system, an important barrier to infections and disease. Despite its importance, for certain ecologically important species, such as solitary bees, our understanding of the genomic basis and molecular mechanisms underlying immune potential, and how intrinsic and extrinsic factors may influence immune gene expression is lacking. Here, to improve our understanding of the genomic architecture underlying immunity of a key solitary bee pollinator, we characterised putative immune genes of the red mason bee, Osmia bicornis. In addition, we used publicly available RNA-seq datasets to determine how sexes differ in immune gene expression and splicing but also how pesticide exposure may affect immune gene expression in females. Through comparative genomics, we reveal an evolutionary conserved set of more than 500 putative immune-related genes. We found genome-wide patterns of sex-biased gene expression, including immune genes involved in antiviral-defence. Interestingly, the expression of certain immune genes were also affected by exposure to common neonicotinoids, particularly genes related to haemocyte proliferation. Collectively, our study provides important insights into the gene repertoire, regulation and expression differences in the sexes of O. bicornis, as well as providing additional support for how neonicotinoids can affect immune gene expression, which may affect the capacity of solitary bees to respond to pathogenic threats.

2021 ◽  
Vol 17 (4) ◽  
pp. e1009552
Author(s):  
Holly L. Nichols ◽  
Elliott B. Goldstein ◽  
Omid Saleh Ziabari ◽  
Benjamin J. Parker

Host genetic variation plays an important role in the structure and function of heritable microbial communities. Recent studies have shown that insects use immune mechanisms to regulate heritable symbionts. Here we test the hypothesis that variation in symbiont density among hosts is linked to intraspecific differences in the immune response to harboring symbionts. We show that pea aphids (Acyrthosiphon pisum) harboring the bacterial endosymbiontRegiella insecticola(but not all other species of symbionts) downregulate expression of key immune genes. We then functionally link immune expression with symbiont density using RNAi. The pea aphid species complex is comprised of multiple reproductively-isolated host plant-adapted populations. These ‘biotypes’ have distinct patterns of symbiont infections: for example, aphids from theTrifoliumbiotype are strongly associated withRegiella. Using RNAseq, we compare patterns of gene expression in response toRegiellain aphid genotypes from multiple biotypes, and we show thatTrifoliumaphids experience no downregulation of immune gene expression while hostingRegiellaand harbor symbionts at lower densities. Using F1 hybrids between two biotypes, we find that symbiont density and immune gene expression are both intermediate in hybrids. We propose that in this system,Regiellasymbionts are suppressing aphid immune mechanisms to increase their density, but that some hosts have adapted to prevent immune suppression in order to control symbiont numbers. This work therefore suggests that antagonistic coevolution can play a role in host-microbe interactions even when symbionts are transmitted vertically and provide a clear benefit to their hosts. The specific immune mechanisms that we find are downregulated in the presence ofRegiellahave been previously shown to combat pathogens in aphids, and thus this work also highlights the immune system’s complex dual role in interacting with both beneficial and harmful microbes.


Genes ◽  
2019 ◽  
Vol 10 (11) ◽  
pp. 889 ◽  
Author(s):  
West ◽  
Watts ◽  
Smith ◽  
Zhang ◽  
Besseling-van der Vaart ◽  
...  

Probiotic supplementation for eight weeks with a multi-strain probiotic by individuals with allergic rhinitis (AR) reduced overall symptom severity, the frequency of medication use and improved quality of life. The purported mechanism of action is modulation of the immune system. This analysis examined changes in systemic and mucosal immune gene expression in a subgroup of individuals, classified as either responders or non-responders based on improvement of AR symptoms in response to the probiotic supplement. Based on established criteria of a beneficial change in the mini-rhinoconjunctivitis quality of life questionnaire (mRQLQ), individuals with AR were classified as either responders or non-responders. Systemic and mucosal immune gene expression was assessed using nCounter PanCancer Immune Profiling (Nanostring Technologies, Seattle, WA, USA) kit on blood samples and a nasal lysate. There were 414 immune genes in the blood and 312 immune genes in the mucosal samples expressed above the background threshold. Unsupervised hierarchical clustering of immune genes separated responders from non-responders in blood and mucosal samples at baseline and after supplementation, with key T-cell immune genes differentially expressed between the groups. Striking differences in biological processes and pathways were evident in nasal mucosa but not blood in responders compared to non-responders. These findings support the use of network approaches to understand probiotic-induced changes to the immune system.


2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 277-277
Author(s):  
Ranjit Joseph ◽  
Kyla Collins ◽  
Dante S. Bortone ◽  
Benjamin Garrett Vincent ◽  
Jen Jen Yeh ◽  
...  

277 Background: PDAC is a lethal disease with poor survival even when detected at an early stage. Recurrence rates after surgical resection remain high. Recently, two distinct molecular subtypes of PDAC (basal-like and classical) have been identified with basal-like tumors demonstrating inferior outcomes. We hypothesize that differences in tumor immunogenicity may contribute to this aggressive biology and predict response to immune checkpoint inhibitors. Methods: RNA sequencing was performed on formalin-fixed paraffin embedded samples of 60 resected PDAC patients. We evaluated previously published immune gene expression signatures comprised of 1400 genes and used a single sample classifier to determine molecular subtypes. Results: Table 1 summarizes patient characteristics in our cohort. There were 35 classical and 25 basal-like tumors. PFS was significantly shorter in patients with basal-like compared to classical subtypes (9 vs 15 mo, p = 0.006). In a multivariable model with molecular subtype, lymph node and margin status, subtype was the only independent predictor of PFS (p=0.028). Unsupervised clustering identified two distinct immune groups that were associated with molecular subtypes (p=0.038) with higher expression of immune genes in basal-like tumors. Basal-like tumors were significantly associated with an immunosuppressive signature (p<0.001) and a signature associated with non-response to PD-1 inhibition in melanoma (p=0.001). Conclusions: This is the first study to show that basal-like pancreatic cancers are associated with increased immune gene expression and may help explain their inferior prognosis. We hypothesize that this reflects an increase in immunosuppressive cells in basal-like tumors that may predict decreased response to immune check point inhibitors. [Table: see text]


2021 ◽  
Vol 8 ◽  
Author(s):  
Chauncy Hinshaw ◽  
Kathleen C. Evans ◽  
Cristina Rosa ◽  
Margarita M. López-Uribe

Studies of the ecoimmunology of feral organisms can provide valuable insight into how host–pathogen dynamics change as organisms transition from human-managed conditions back into the wild. Honey bees (Apis mellifera Linnaeus) offer an ideal system to investigate these questions as colonies of these social insects often escape management and establish in the wild. While managed honey bee colonies have low probability of survival in the absence of disease treatments, feral colonies commonly survive in the wild, where pathogen pressures are expected to be higher due to the absence of disease treatments. Here, we investigate the role of pathogen infections [Deformed wing virus (DWV), Black queen cell virus (BQCV), and Nosema ceranae] and immune gene expression (defensin-1, hymenoptaecin, pgrp-lc, pgrp-s2, argonaute-2, vago) in the survival of feral and managed honey bee colonies. We surveyed a total of 25 pairs of feral and managed colonies over a 2-year period (2017–2018), recorded overwintering survival, and measured pathogen levels and immune gene expression using quantitative polymerase chain reaction (qPCR). Our results showed that feral colonies had higher levels of DWV but it was variable over time compared to managed colonies. Higher pathogen levels were associated with increased immune gene expression, with feral colonies showing higher expression in five out of the six examined immune genes for at least one sampling period. Further analysis revealed that differential expression of the genes hymenoptaecin and vago increased the odds of overwintering survival in managed and feral colonies. Our results revealed that feral colonies express immune genes at higher levels in response to high pathogen burdens, providing evidence for the role of feralization in altering pathogen landscapes and host immune responses.


2013 ◽  
Vol 10 (2) ◽  
pp. 2675-2703 ◽  
Author(s):  
E. Martins ◽  
A. Queiroz ◽  
R. Serrão Santos ◽  
R. Bettencourt

Abstract. The deep-sea hydrothermal vent mussel Bathymodiolus azoricus lives in a natural environment characterized by extreme conditions of hydrostatic pressure, temperature, pH, high concentrations of heavy metals, methane and hydrogen sulphide. The deep-sea vent biological systems represent thus the opportunity to study and provide new insights into the basic physiological principles that govern the defense mechanisms in vent animals and to understand how they cope with microbial infections. Hence, the importance of understanding this animal's innate defense mechanisms, by examining its differential immune gene expressions toward different pathogenic agents. In the present study, B. azoricus mussels were infected with single suspensions of marine bacterial pathogens, consisting of Vibrio splendidus, Vibrio alginolyticus, or Vibrio anguillarum, and a pool of these Vibrio strains. Flavobacterium suspensions were also used as an irrelevant bacterium. Gene expression analyses were carried out using gill samples from animals dissected at 12 h and 24 h post-infection times by means of quantitative-Polymerase Chain Reaction aimed at targeting several immune genes. We also performed SDS-PAGE protein analyses from the same gill tissues. We concluded that there are different levels of immune gene expression between the 12 h and 24 h exposure times to various bacterial suspensions. Our results from qPCR demonstrated a general pattern of gene expression, decreasing from 12 h over 24 h post-infection. Among the bacteria tested, Flavobacterium is the microorganism species inducing the highest gene expression level in 12 h post-infections animals. The 24 h infected animals revealed, however, greater gene expression levels, using V. splendidus as the infectious agent. The SDS-PAGE analysis also pointed at protein profile differences between 12 h and 24 h, particularly around a protein area, of 18 KDa molecular mass, where most dissimilarities were found. Multivariate analyses demonstrated that immune genes, as well as experimental infections, clustered in discrete groups in accordance with the patterns observed in gene expression changes induced by bacterial pathogens.


2013 ◽  
Vol 10 (11) ◽  
pp. 7279-7291 ◽  
Author(s):  
E. Martins ◽  
A. Queiroz ◽  
R. Serrão Santos ◽  
R. Bettencourt

Abstract. The deep-sea hydrothermal vent mussel Bathymodiolus azoricus lives in a natural environment characterised by extreme conditions of hydrostatic pressure, temperature, pH, high concentrations of heavy metals, methane and hydrogen sulphide. The deep-sea vent biological systems represent thus the opportunity to study and provide new insights into the basic physiological principles that govern the defense mechanisms in vent animals and to understand how they cope with microbial infections. Hence, the importance of understanding this animal's innate defense mechanisms, by examining its differential immune gene expressions toward different pathogenic agents. In the present study, B. azoricus mussels were infected with single suspensions of marine bacterial pathogens, consisting of Vibrio splendidus, Vibrio alginolyticus, or Vibrio anguillarum, and a pool of these Vibrio bacteria. Flavobacterium suspensions were also used as a non-pathogenic bacterium. Gene expression analyses were carried out using gill samples from infected animals by means of quantitative-Polymerase Chain Reaction aimed at targeting several immune genes. We also performed SDS-PAGE protein analyses from the same gill tissues. We concluded that there are different levels of immune gene expression between the 12 h to 24 h exposure times to various bacterial suspensions. Our results from qPCR demonstrated a general pattern of gene expression, decreasing from 12 h over 24 h post-infection. Among the bacteria tested, Flavobacterium is the bacterium inducing the highest gene expression level in 12 h post-infections animals. The 24 h infected animals revealed, however, greater gene expression levels, using V. splendidus as the infectious agent. The SDS-PAGE analysis also pointed at protein profile differences between 12 h and 24 h, particularly evident for proteins of 18–20 KDa molecular mass, where most dissimilarity was found. Multivariate analyses demonstrated that immune genes, as well as experimental infections, clustered in discrete groups in accordance with the gene expression patterns induced by bacterial pathogens.


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