scholarly journals Comparative Genome Sequence Analysis Reveals the Extent of Diversity and Conservation for Glycan-Associated Proteins inBurkholderiaspp.

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Hui San Ong ◽  
Rahmah Mohamed ◽  
Mohd Firdaus-Raih

Members of theBurkholderiafamily occupy diverse ecological niches. In pathogenic family members, glycan-associated proteins are often linked to functions that include virulence, protein conformation maintenance, surface recognition, cell adhesion, and immune system evasion. Comparative analysis of availableBurkholderiagenomes has revealed a core set of 178 glycan-associated proteins shared by allBurkholderiaof which 68 are homologous to known essential genes. The genome sequence comparisons revealed insights into species-specific gene acquisitions through gene transfers, identified an S-layer protein, and proposed that significantly reactive surface proteins are associated to sugar moieties as a potential means to circumvent host defense mechanisms. The comparative analysis using a curated database of search queries enabled us to gain insights into the extent of conservation and diversity, as well as the possible virulence-associated roles of glycan-associated proteins in members of theBurkholderiaspp. The curated list of glycan-associated proteins used can also be directed to screen other genomes for glycan-associated homologs.

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Kenro Oshima ◽  
Kenji Ueda ◽  
Teruhiko Beppu ◽  
Hiromi Nishida

Comparisons of gene content and orthologous protein sequence constitute a major strategy in whole-genome comparison studies. It is expected that horizontal gene transfer between phylogenetically distant organisms and lineage-specific gene loss have greater influence on gene content-based phylogenetic analysis than orthologous protein sequence-based phylogenetic analysis. To determine the evolution of the syntrophic bacterium Symbiobacterium thermophilum, we analyzed phylogenetic relationships among Clostridia on the basis of gene content and orthologous protein sequence comparisons. These comparisons revealed that these 2 phylogenetic relationships are topologically different. Our results suggest that each Clostridia has a species-specific gene content because frequent genetic exchanges or gene losses have occurred during evolution. Specifically, the phylogenetic positions of syntrophic Clostridia were different between these 2 phylogenetic analyses, suggesting that large diversity in the living environments may cause the observed species-specific gene content. S. thermophilum occupied the most distant position from the other syntrophic Clostridia in the gene content-based phylogenetic tree. We identified 32 genes (14 under relaxed selection and 18 under functional constraint) evolving under Symbiobacterium-specific selection on the basis of synonymous-to-nonsynonymous substitution ratios. Five of the 14 genes under relaxed selection are related to transcription. In contrast, none of the 18 genes under functional constraint is related to transcription.


2016 ◽  
Author(s):  
Aaron W. Reinke ◽  
Keir M. Balla ◽  
Eric J. Bennett ◽  
Emily R. Troemel

AbstractPathogens use a variety of secreted and surface proteins to interact with and manipulate their hosts, but a systematic approach for identifying such proteins has been lacking. To identify these ‘host-exposed’ proteins, we used spatially restricted enzymatic tagging followed by mass spectrometry analysis of C. elegans infected with two species of Nematocida microsporidia. We identified 82 microsporidia proteins inside of intestinal cells, including several pathogen proteins in the nucleus. These microsporidia proteins are enriched in targeting signals, are rapidly evolving, and belong to large, Nematocida-specific gene families. We also find that large, species-specific families are common throughout microsporidia species. Our data suggest that the use of a large number of rapidly evolving species-specific proteins represents a common strategy for these intracellular pathogens to interact with their hosts. The unbiased method described here for identifying potential pathogen effectors represents a powerful approach for the study of a broad range of pathogens.


2019 ◽  
Vol 71 (6) ◽  
pp. 1899-1914
Author(s):  
Zhi-Gang Wu ◽  
Wu Jiang ◽  
Zheng-Ming Tao ◽  
Xiao-Jun Pan ◽  
Wen-Hui Yu ◽  
...  

Abstract In yam (Dioscorea spp) species, bulbils at leaf axils are the most striking species-specific axillary structure and exhibit important ecological niches. Genetic regulation underlying bulbil growth remains largely unclear so far. Here, we characterize yam (Dioscorea alata L.) bulbil development using histological analysis, and perform full transcriptional profiling on key developmental stages together with phytohormone analyses. Using the stage-specific scoring algorithm, we have identified 3451 stage-specifically expressed genes that exhibit a tight link between major transcriptional changes and stages. Co-expressed gene clusters revealed an obvious over-representation of genes associated with cell division and expansion at the initiation stage of bulbils (T1). Transcriptional changes of hormone-related genes highly coincided with hormone levels, indicating that bulbil initiation and growth are coordinately controlled by multiple phytohormones. In particular, localized auxin is transiently required to trigger bulbil initiation, and be further depleted or exported from bulbils to promote growth by up-regulation of genes involved in auxinconjugation and efflux. The sharp increase in supply of sucrose and an enhanced trehalose-6-phophate pathway at T1 were observed, suggesting that sucrose probably functions as a key signal and promotes bulbil initiation. Analysis of the expression of transcription factors (TFs) predicated 149 TFs as stage-specifically expressed; several T1-specific TFs (from Aux/IAA, E2F, MYB, and bHLH families) have been shown to play key roles in triggering bulbil formation. Together, our work provides a crucial angle for in-depth understanding of the molecular programs underlying yam’s unique bulbil development processes. Stage-specific gene sets can be queried to obtain key candidates regulating bulbil growth, serving as valuable resources for further functional research.


2014 ◽  
Author(s):  
Olgert Denas ◽  
Richard Sandstrom ◽  
Yong Cheng ◽  
Kathryn Beal ◽  
Javier Herrero ◽  
...  

Background: Because species-specific gene expression is driven by species-specific regulation, understanding the relationship between sequence and function of the regulatory regions in different species will help elucidate how differences among species arise. Despite active experimental and computational research, the relationships among sequence, conservation, and function are still poorly understood. Results: We compared transcription factor occupied segments (TFos) for 116 human and 35 mouse TFs in 546 human and 125 mouse cell types and tissues from the Human and the Mouse ENCODE projects. We based the map between human and mouse TFos on a one-to-one nucleotide cross-species mapper, bnMapper, that utilizes whole genome alignments (WGA). Our analysis shows that TFos are under evolutionary constraint, but a substantial portion (25.1% of mouse and 25.85% of human on average) of the TFos does not have a homologous sequence on the other species; this portion varies among cell types and TFs. Furthermore, 47.67% and 57.01% of the homologous TFos sequence shows binding activity on the other species for human and mouse respectively. However, 79.87% and 69.22% is repurposed such that it binds the same TF in different cells or different TFs in the same cells. Remarkably, within the set of TFos not showing conservation of occupancy, the corresponding genome regions in the other species are preferred locations of novel TFos. These events suggest that a substantial amount of functional regulatory sequences is exapted from other biochemically active genomic material. Despite substantial repurposing of TFos, we did not find substantial changes in their predicted target genes, suggesting that CRMs buffer evolutionary events allowing little or no change in the TF – target gene associations. Thus, the small portion of TFos with strictly conserved occupancy underestimates the degree of conservation of regulatory interactions. Conclusion: We mapped regulatory sequences from an extensive number of TFs and cell types between human and mouse. A comparative analysis of this correspondence unveiled the extent of the shared regulatory sequence across TFs and cell types under study. Importantly, a large part of the shared regulatory sequence repurposed on the other species. This sequence, fueled by turnover events, provides a strong case for exaptation in regulatory elements.


Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 518
Author(s):  
Zequn Chen ◽  
Xiwu Qi ◽  
Xu Yu ◽  
Ying Zheng ◽  
Zhiqi Liu ◽  
...  

Terpenoids are a wide variety of natural products and terpene synthase (TPS) plays a key role in the biosynthesis of terpenoids. Mentha plants are rich in essential oils, whose main components are terpenoids, and their biosynthetic pathways have been basically elucidated. However, there is a lack of systematic identification and study of TPS in Mentha plants. In this work, we genome-widely identified and analyzed the TPS gene family in Mentha longifolia, a model plant for functional genomic research in the genus Mentha. A total of 63 TPS genes were identified in the M. longifolia genome sequence assembly, which could be divided into six subfamilies. The TPS-b subfamily had the largest number of genes, which might be related to the abundant monoterpenoids in Mentha plants. The TPS-e subfamily had 18 members and showed a significant species-specific expansion compared with other sequenced Lamiaceae plant species. The 63 TPS genes could be mapped to nine scaffolds of the M. longifolia genome sequence assembly and the distribution of these genes is uneven. Tandem duplicates and fragment duplicates contributed greatly to the increase in the number of TPS genes in M. longifolia. The conserved motifs (RR(X)8W, NSE/DTE, RXR, and DDXXD) were analyzed in M. longifolia TPSs, and significant differentiation was found between different subfamilies. Adaptive evolution analysis showed that M. longifolia TPSs were subjected to purifying selection after the species-specific expansion, and some amino acid residues under positive selection were identified. Furthermore, we also cloned and analyzed the catalytic activity of a single terpene synthase, MlongTPS29, which belongs to the TPS-b subfamily. MlongTPS29 could encode a limonene synthase and catalyze the biosynthesis of limonene, an important precursor of essential oils from the genus Mentha. This study provides useful information for the biosynthesis of terpenoids in the genus Mentha.


2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Zhaocai Li ◽  
Ping Liu ◽  
Xiaoan Cao ◽  
Zhongzi Lou ◽  
Kinga Zaręba-Marchewka ◽  
...  

Chlamydia (C.) abortus, a globally distributed obligate intracellular bacterium, has attracted increasing interest according to its veterinary importance and zoonotic nature. C. abortus can infect a variety of animals and cause foetal loss in livestock resulting in economic loss. In this study, the samples collected from two farms of foxes (n=20), raccoon dogs (n=15) and minks (n=20), were investigated by Chlamydiaceae- and Chlamydia species-specific real-time PCR. The results showed that all the tested foxes (20/20) and raccoon dogs (15/15) harbored Chlamydia spp., while 5% of minks (1/20) were positive for Chlamydia spp. C. abortus was identified in all positive samples as the dominant Chlamydia species, with C. pecorum DNA coexistence in some of the rectal samples (7/20) taken from foxes. Phylogenetic analysis based on specific gene fragments of 16S rRNA, IGS-23S rRNA, and ompA revealed that all sequences obtained in this study were assigned to the Chlamydiaceae family with high similarity to C. abortus S26/3 and B577 previously identified in ruminants. This is the first report confirming that farmed foxes, raccoon dogs, and minks carry C. abortus. Further studies are needed to fully elucidate the epidemiology and pathogenicity of this pathogen in farmed fur animals as well as the potential risks to public health.


2007 ◽  
Vol 17 (7) ◽  
pp. 1082-1092 ◽  
Author(s):  
M. Sebaihia ◽  
M. W. Peck ◽  
N. P. Minton ◽  
N. R. Thomson ◽  
M. T.G. Holden ◽  
...  

2021 ◽  
Vol 22 (7) ◽  
pp. 3406
Author(s):  
Robert L. Medcalf ◽  
Charithani B. Keragala

The fibrinolytic system provides an essential means to remove fibrin deposits and blood clots. The actual protease responsible for this is plasmin, formed from its precursor, plasminogen. Fibrin is heralded as it most renowned substrate but for many years plasmin has been known to cleave many other substrates, and to also activate other proteolytic systems. Recent clinical studies have shown that the promotion of plasmin can lead to an immunosuppressed phenotype, in part via its ability to modulate cytokine expression. Almost all immune cells harbor at least one of a dozen plasminogen receptors that allows plasmin formation on the cell surface that in turn modulates immune cell behavior. Similarly, a multitude of pathogens can also express their own plasminogen activators, or contain surface proteins that provide binding sites host plasminogen. Plasmin formed under these circumstances also empowers these pathogens to modulate host immune defense mechanisms. Phylogenetic studies have revealed that the plasminogen activating system predates the appearance of fibrin, indicating that plasmin did not evolve as a fibrinolytic protease but perhaps has its roots as an immune modifying protease. While its fibrin removing capacity became apparent in lower vertebrates these primitive under-appreciated immune modifying functions still remain and are now becoming more recognised.


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