scholarly journals Evolution of Toll, Spatzle and MyD88 in insects: the problem of the Diptera bias

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Letícia Ferreira Lima ◽  
André Quintanilha Torres ◽  
Rodrigo Jardim ◽  
Rafael Dias Mesquita ◽  
Renata Schama

Abstract Background Arthropoda, the most numerous and diverse metazoan phylum, has species in many habitats where they encounter various microorganisms and, as a result, mechanisms for pathogen recognition and elimination have evolved. The Toll pathway, involved in the innate immune system, was first described as part of the developmental pathway for dorsal-ventral differentiation in Drosophila. Its later discovery in vertebrates suggested that this system was extremely conserved. However, there is variation in presence/absence, copy number and sequence divergence in various genes along the pathway. As most studies have only focused on Diptera, for a comprehensive and accurate homology-based approach it is important to understand gene function in a number of different species and, in a group as diverse as insects, the use of species belonging to different taxonomic groups is essential. Results We evaluated the diversity of Toll pathway gene families in 39 Arthropod genomes, encompassing 13 different Insect Orders. Through computational methods, we shed some light into the evolution and functional annotation of protein families involved in the Toll pathway innate immune response. Our data indicates that: 1) intracellular proteins of the Toll pathway show mostly species-specific expansions; 2) the different Toll subfamilies seem to have distinct evolutionary backgrounds; 3) patterns of gene expansion observed in the Toll phylogenetic tree indicate that homology based methods of functional inference might not be accurate for some subfamilies; 4) Spatzle subfamilies are highly divergent and also pose a problem for homology based inference; 5) Spatzle subfamilies should not be analyzed together in the same phylogenetic framework; 6) network analyses seem to be a good first step in inferring functional groups in these cases. We specifically show that understanding Drosophila’s Toll functions might not indicate the same function in other species. Conclusions Our results show the importance of using species representing the different orders to better understand insect gene content, origin and evolution. More specifically, in intracellular Toll pathway gene families the presence of orthologues has important implications for homology based functional inference. Also, the different evolutionary backgrounds of Toll gene subfamilies should be taken into consideration when functional studies are performed, especially for TOLL9, TOLL, TOLL2_7, and the new TOLL10 clade. The presence of Diptera specific clades or the ones lacking Diptera species show the importance of overcoming the Diptera bias when performing functional characterization of Toll pathways.

Biomolecules ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1744
Author(s):  
Stefania Pilati ◽  
Giulia Malacarne ◽  
David Navarro-Payá ◽  
Gabriele Tomè ◽  
Laura Riscica ◽  
...  

The abundance of transcriptomic data and the development of causal inference methods have paved the way for gene network analyses in grapevine. Vitis OneGenE is a transcriptomic data mining tool that finds direct correlations between genes, thus producing association networks. As a proof of concept, the stilbene synthase gene regulatory network obtained with OneGenE has been compared with published co-expression analysis and experimental data, including cistrome data for MYB stilbenoid regulators. As a case study, the two secondary metabolism pathways of stilbenoids and lignin synthesis were explored. Several isoforms of laccase, peroxidase, and dirigent protein genes, putatively involved in the final oxidative oligomerization steps, were identified as specifically belonging to either one of these pathways. Manual curation of the predicted sequences exploiting the last available genome assembly, and the integration of phylogenetic and OneGenE analyses, identified a group of laccases exclusively present in grapevine and related to stilbenoids. Here we show how network analysis by OneGenE can accelerate knowledge discovery by suggesting new candidates for functional characterization and application in breeding programs.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0256873
Author(s):  
Fee Faysal Ahmed ◽  
Md. Imran Hossen ◽  
Md. Abdur Rauf Sarkar ◽  
Jesmin Naher Konak ◽  
Fatema Tuz Zohra ◽  
...  

RNA silencing is mediated through RNA interference (RNAi) pathway gene families, i.e., Dicer-Like (DCL), Argonaute (AGO), and RNA-dependent RNA polymerase (RDR) and their cis-acting regulatory elements. The RNAi pathway is also directly connected with the post-transcriptional gene silencing (PTGS) mechanism, and the pathway controls eukaryotic gene regulation during growth, development, and stress response. Nevertheless, genome-wide identification of RNAi pathway gene families such as DCL, AGO, and RDR and their regulatory network analyses related to transcription factors have not been studied in many fruit crop species, including banana (Musa acuminata). In this study, we studied in silico genome-wide identification and characterization of DCL, AGO, and RDR genes in bananas thoroughly via integrated bioinformatics approaches. A genome-wide analysis identified 3 MaDCL, 13 MaAGO, and 5 MaRDR candidate genes based on multiple sequence alignment and phylogenetic tree related to the RNAi pathway in banana genomes. These genes correspond to the Arabidopsis thaliana RNAi silencing genes. The analysis of the conserved domain, motif, and gene structure (exon-intron numbers) for MaDCL, MaAGO, and MaRDR genes showed higher homogeneity within the same gene family. The Gene Ontology (GO) enrichment analysis exhibited that the identified RNAi genes could be involved in RNA silencing and associated metabolic pathways. A number of important transcription factors (TFs), e.g., ERF, Dof, C2H2, TCP, GATA and MIKC_MADS families, were identified by network and sub-network analyses between TFs and candidate RNAi gene families. Furthermore, the cis-acting regulatory elements related to light-responsive (LR), stress-responsive (SR), hormone-responsive (HR), and other activities (OT) functions were identified in candidate MaDCL, MaAGO, and MaRDR genes. These genome-wide analyses of these RNAi gene families provide valuable information related to RNA silencing, which would shed light on further characterization of RNAi genes, their regulatory elements, and functional roles, which might be helpful for banana improvement in the breeding program.


1992 ◽  
Vol 67 (02) ◽  
pp. 219-225 ◽  
Author(s):  
Walter A Wuillemin ◽  
Miha Furlan ◽  
Hans Stricker ◽  
Bernhard Lämmle

SummaryThe plasma of a healthy woman was found to contain half normal factor XII (FXII) antigen level (0.46 U/ml) without any FXII clotting activity (<0.01 U/ml). The variant FXII in this plasma, denoted as FXII Locarno, was partially characterized by immunological and functional studies on the proposita’s plasma. FXII Locarno is a single chain molecule with the same size (M r = 80 kDa) as normal FXII. Isoelectric focusing suggested an excess of negative charge in the variant FXII as compared to normal FXII. In contrast to FXII in normal plasma, FXII Locarno was not proteolytically cleaved upon prolonged incubation of proposita’s plasma with dextran sulfate. Adsorption to kaolin was similar for both, abnormal and normal FXII. Incubation of the proposita’s plasma with dextran sulfate and exogenous plasma kallikrein showed normal cleavage of FXII Locarno outside of the tentative disulfide loop Cys340-Cys467, but only partial cleavage within this disulfide loop. Furthermore, plasma kallikrein-cleaved abnormal FXII showed neither amidolytic activity nor proteolytic activity against factor XI and plasma prekallikrein.These results suggest a structural alteration of FXII Locarno, affecting the plasma kallikrein cleavage site Arg353-Val354 and thus formation of activated FXII (a-FXIIa).


2021 ◽  
Vol 22 (6) ◽  
pp. 2858
Author(s):  
Faustino Bisaccia ◽  
Prashant Koshal ◽  
Vittorio Abruzzese ◽  
Maria Antonietta Castiglione Morelli ◽  
Angela Ostuni

Pseudoxanthoma elasticum (PXE) is a complex autosomal recessive disease caused by mutations of ABCC6 transporter and characterized by ectopic mineralization of soft connective tissues. Compared to the other ABC transporters, very few studies are available to explain the structural components and working of a full ABCC6 transporter, which may provide some idea about its physiological role in humans. Some studies suggest that mutations of ABCC6 in the liver lead to a decrease in some circulating factor and indicate that PXE is a metabolic disease. It has been reported that ABCC6 mediates the efflux of ATP, which is hydrolyzed in PPi and AMP; in the extracellular milieu, PPi gives potent anti-mineralization effect, whereas AMP is hydrolyzed to Pi and adenosine which affects some cellular properties by modulating the purinergic pathway. Structural and functional studies have demonstrated that silencing or inhibition of ABCC6 with probenecid changed the expression of several genes and proteins such as NT5E and TNAP, as well as Lamin, and CDK1, which are involved in cell motility and cell cycle. Furthermore, a change in cytoskeleton rearrangement and decreased motility of HepG2 cells makes ABCC6 a potential target for anti-cancer therapy. Collectively, these findings suggested that ABCC6 transporter performs functions that modify both the external and internal compartments of the cells.


2015 ◽  
Vol 308 (2) ◽  
pp. C123-C138 ◽  
Author(s):  
E. Giacomello ◽  
M. Quarta ◽  
C. Paolini ◽  
R. Squecco ◽  
P. Fusco ◽  
...  

Muscle-specific ankyrins 1 (sAnk1) are a group of small ankyrin 1 isoforms, of which sAnk1.5 is the most abundant. sAnk1 are localized in the sarcoplasmic reticulum (SR) membrane from where they interact with obscurin, a myofibrillar protein. This interaction appears to contribute to stabilize the SR close to the myofibrils. Here we report the structural and functional characterization of skeletal muscles from sAnk1 knockout mice (KO). Deletion of sAnk1 did not change the expression and localization of SR proteins in 4- to 6-mo-old sAnk1 KO mice. Structurally, the main modification observed in skeletal muscles of adult sAnk1 KO mice (4–6 mo of age) was the reduction of SR volume at the sarcomere A band level. With increasing age (at 12–15 mo of age) extensor digitorum longus (EDL) skeletal muscles of sAnk1 KO mice develop prematurely large tubular aggregates, whereas diaphragm undergoes significant structural damage. Parallel functional studies revealed specific changes in the contractile performance of muscles from sAnk1 KO mice and a reduced exercise tolerance in an endurance test on treadmill compared with control mice. Moreover, reduced Qγcharge and L-type Ca2+current, which are indexes of affected excitation-contraction coupling, were observed in diaphragm fibers from 12- to 15-mo-old mice, but not in other skeletal muscles from sAnk1 KO mice. Altogether, these findings show that the ablation of sAnk1, by altering the organization of the SR, renders skeletal muscles susceptible to undergo structural and functional alterations more evident with age, and point to an important contribution of sAnk1 to the maintenance of the longitudinal SR architecture.


2017 ◽  
Vol 12 (1) ◽  
pp. 266-276
Author(s):  
Bi Ma ◽  
Lulu Kuang ◽  
Youchao Xin ◽  
Fei Hou ◽  
Ningjia He

AbstractCopia and Gypsy play important roles in structural, functional and evolutionary dynamics of plant genomes. In this study, a total of 106 and 101, Copia and Gypsy reverse transcriptase (rt) were amplified respectively in the Morus notabilis genome using degenerate primers. All sequences exhibited high levels of heterogeneity, were rich in AT and possessed higher sequence divergence of Copia rt in comparison to Gypsy rt. Two reasons are likely to account for this phenomenon: a) these elements often experience deletions or fragmentation by illegitimate or unequal homologous recombination in the transposition process; b) strong purifying selective pressure drives the evolution of these elements through “selective silencing” with random mutation and eventual deletion from the host genome. Interestingly, mulberry rt clustered with other rt from distantly related taxa according to the phylogenetic analysis. This phenomenon did not result from horizontal transposable element transfer. Results obtained from fluorescence in situ hybridization revealed that most of the hybridization signals were preferentially concentrated in pericentromeric and distal regions of chromosomes, and these elements may play important roles in the regions in which they are found. Results of this study support the continued pursuit of further functional studies of Copia and Gypsy in the mulberry genome.


2020 ◽  
Vol 21 (5) ◽  
pp. 1752 ◽  
Author(s):  
Jin Yang ◽  
Jie Zhou ◽  
Hong-Jun Zhou ◽  
Mang-Mang Wang ◽  
Ming-Ming Liu ◽  
...  

Phosphate (Pi) transporters play critical roles in Pi acquisition and homeostasis. However, currently little is known about these genes in oil crops. In this study, we aimed to characterize the five Pi transporter gene families (PHT1-5) in allotetraploid Brassica napus. We identified and characterized 81 putative PHT genes in B. napus (BnaPHTs), including 45 genes in PHT1 family (BnaPHT1s), four BnaPHT2s, 10 BnaPHT3s, 13 BnaPHT4s and nine BnaPHT5s. Phylogenetic analyses showed that the largest PHT1 family could be divided into two groups (Group I and II), while PHT4 may be classified into five, Groups I-V. Gene structure analysis revealed that the exon-intron pattern was conservative within the same family or group. The sequence characteristics of these five families were quite different, which may contribute to their functional divergence. Transcription factor (TF) binding network analyses identified many potential TF binding sites in the promoter regions of candidates, implying their possible regulating patterns. Collinearity analysis demonstrated that most BnaPHTs were derived from an allopolyploidization event (~40.7%) between Brassica rapa and Brassica oleracea ancestors, and small-scale segmental duplication events (~39.5%) in the descendant. RNA-Seq analyses proved that many BnaPHTs were preferentially expressed in leaf and flower tissues. The expression profiles of most colinearity-pairs in B. napus are highly correlated, implying functional redundancy, while a few pairs may have undergone neo-functionalization or sub-functionalization during evolution. The expression levels of many BnaPHTs tend to be up-regulated by different hormones inductions, especially for IAA, ABA and 6-BA treatments. qRT-PCR assay demonstrated that six BnaPHT1s (BnaPHT1.11, BnaPHT1.14, BnaPHT1.20, BnaPHT1.35, BnaPHT1.41, BnaPHT1.44) were significantly up-regulated under low- and/or rich- Pi conditions in B. napus roots. This work analyzes the evolution and expression of the PHT family in Brassica napus, which will help further research on their role in Pi transport.


2019 ◽  
Author(s):  
Mosè Manni ◽  
Felipe A. Simao ◽  
Hugh M. Robertson ◽  
Marco A. Gabaglio ◽  
Robert M. Waterhouse ◽  
...  

AbstractThe dipluran two-pronged bristletail Campodea augens is a blind ancestrally wingless hexapod with the remarkable capacity to regenerate lost body appendages such as its long antennae. As sister group to Insecta (sensu stricto), Diplura are key to understanding the early evolution of hexapods and the origin and evolution of insects. Here we report the 1.2-Gbp draft genome of C. augens and results from comparative genomic analyses with other arthropods. In C. augens we uncovered the largest chemosensory gene repertoire of ionotropic receptors in the animal kingdom, a massive expansion which might compensate for the loss of vision. We found a paucity of photoreceptor genes mirroring at the genomic level the secondary loss of an ancestral external photoreceptor organ. Expansions of detoxification and carbohydrate metabolism gene families might reflect adaptations for foraging behaviour, and duplicated apoptotic genes might underlie its high regenerative potential.The C. augens genome represents one of the key references for studying the emergence of genomic innovations in insects, the most diverse animal group, and opens up novel opportunities to study the under-explored biology of diplurans.


2018 ◽  
Author(s):  
Juan F Ortiz ◽  
Antonis Rokas

Clusters of duplicated genes (CTDGs) are nearly ubiquitous in life's genomes, and are associated with several well-known gene families, such as olfactory receptors, zinc fingers, and immunity-related genes, as well as with several highly variable traits, including olfaction, body plan architecture, and pathogen resistance. However, these observations are usually anecdotal, restricted to specific cases, and lacking evolutionary context. In this study, we use a robust statistical approach to characterize the CTDG repertoire and analyze the distribution of CTDGs across 18 mammal genomes, including human. We found that, on average, 18% of the genes in each species are parts of CTDGs. Although genes in CTDGs are enriched for several biological processes, these tend to be involved in the interactions between the organism and its environment. We further found that mammalian CTDGs are not uniformly distributed across chromosomes and that orthologs of the human chromosome 19 are among the most clustered chromosomes in nearly all mammalian genomes analyzed. We also found evidence that the human chromosome 19 was formed by a fusion event that occurred before the diversification of the rodent and primate lineages and maintained its high density of CTDGs during its subsequent evolution. Finally, using chromosome-level alignments across mammalian genomes, we show how the syntenic regions of the human chromosome 19 have been shrinking, increasing their gene density and possibly increasing the compactness of its CTDGs. These results suggest that CTDGs are a major feature of mammalian genomes and provide novel insights into the origin and evolution of regions with unusually high densities of CTDGs.


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