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2022 ◽  
Author(s):  
Meghan Diefenbacher ◽  
Timothy J.C. Tan ◽  
David L.V. Bauer ◽  
Beth Stadtmueller ◽  
Nicholas C. Wu ◽  
...  

The influenza A virus (IAV) genome is divided into eight negative-sense, single-stranded RNA segments. Each segment exhibits a unique level and temporal pattern of expression, however the exact mechanisms underlying the patterns of individual gene segment expression are poorly understood. We previously demonstrated that a single substitution in the viral nucleoprotein (NP:F346S) selectively modulates neuraminidase (NA) gene segment expression while leaving other segments largely unaffected. Given what is currently known about NP function, there is no obvious explanation for how changes in NP can selectively modulate the replication of individual gene segments. We found that the specificity of this effect for the NA segment is virus strain specific and depends on the UTR sequences of the NA segment. While the NP:F346S substitution did not significantly alter the RNA binding or oligomerization activities of NP in vitro, it specifically decreased the ability of NP to promote NA segment vRNA synthesis. In addition to NP residue F346, we identified two other adjacent aromatic residues in NP (Y385 & F479) capable of similarly regulating NA gene segment expression, suggesting a larger role for this domain in gene-segment specific regulation. Our findings reveal a new role for NP in selective regulation of viral gene segment replication and demonstrate how the expression patterns of individual viral gene segments can be modulated during adaptation to new host environments.


2022 ◽  
Vol 23 (1) ◽  
Author(s):  
Julia Vetter ◽  
Susanne Schaller ◽  
Andreas Heinzel ◽  
Constantin Aschauer ◽  
Roman Reindl-Schwaighofer ◽  
...  

Abstract Background Next-generation sequencing (NGS) is nowadays the most used high-throughput technology for DNA sequencing. Among others NGS enables the in-depth analysis of immune repertoires. Research in the field of T cell receptor (TCR) and immunoglobulin (IG) repertoires aids in understanding immunological diseases. A main objective is the analysis of the V(D)J recombination defining the structure and specificity of the immune repertoire. Accurate processing, evaluation and visualization of immune repertoire NGS data is important for better understanding immune responses and immunological behavior. Results ImmunoDataAnalyzer (IMDA) is a pipeline we have developed for automatizing the analysis of immunological NGS data. IMDA unites the functionality from carefully selected immune repertoire analysis software tools and covers the whole spectrum from initial quality control up to the comparison of multiple immune repertoires. It provides methods for automated pre-processing of barcoded and UMI tagged immune repertoire NGS data, facilitates the assembly of clonotypes and calculates key figures for describing the immune repertoire. These include commonly used clonality and diversity measures, as well as indicators for V(D)J gene segment usage and between sample similarity. IMDA reports all relevant information in a compact summary containing visualizations, calculations, and sample details, all of which serve for a more detailed overview. IMDA further generates an output file including key figures for all samples, designed to serve as input for machine learning frameworks to find models for differentiating between specific traits of samples. Conclusions IMDA constructs TCR and IG repertoire data from raw NGS reads and facilitates descriptive data analysis and comparison of immune repertoires. The IMDA workflow focus on quality control and ease of use for non-computer scientists. The provided output directly facilitates the interpretation of input data and includes information about clonality, diversity, clonotype overlap as well as similarity, and V(D)J gene segment usage. IMDA further supports the detection of sample swaps and cross-sample contamination that potentially occurred during sample preparation. In summary, IMDA reduces the effort usually required for immune repertoire data analysis by providing an automated workflow for processing raw NGS data into immune repertoires and subsequent analysis. The implementation is open-source and available on https://bioinformatics.fh-hagenberg.at/immunoanalyzer/.


2021 ◽  
Vol 13 (2) ◽  
pp. 32-37
Author(s):  
Hawraa Al-Mohamadawi ◽  
Asaad Y. Ayied

The origin of animals is usually determined by their paternal genotypes of the genes on the Y chromosome. In addition to the genes and their polymorphisms in the genome of mitochondria that are inherited through dams. In view of the lack of studies focusing on the genes of the Y chromosome in the world and their absence in Iraq. The aim of the present study was to identify the multiple genetic polymorphisms of the SRYM18 gene in the Arabi and Awassi sheep raised in Iraq. The study was conducted in the Genetic Engineering Laboratories - College of Agriculture, University of Basra, as well as in the Basra Genome Laboratory. The amplification of the SRYM18 gene showed genetic polymorphisms and gave a gene segment of (103-880) bp. The number of alleles of the SRYm18 gene was 13 alleles in the Arabi and 16 alleles in the Awassi breeds. The equilibrium test showed that the two breeds were under equilibrium. The two breeds were identical with nine alleles, while the number of special alleles for the Arabi breed was two, while the Awassi breed was distinguished by five. The number of rare alleles reached 20, of which seven were of the Arabi breed, and 13 of them were of the Awassi breed. Mean expected heterozygosity was 0.6386 with nonsignificant Fis for Arabi breed (0.1541) but significant for Awassi breed (0.2213). Mean neutrality was close to lower bound (0.1721) and (0.1270) for Arabi and Awassi breeds respectively


2021 ◽  
Vol 11 ◽  
Author(s):  
Antonella Nicolò ◽  
Alexandra Theresa Linder ◽  
Hassan Jumaa ◽  
Palash Chandra Maity

Advanced genome-wide association studies (GWAS) identified several transforming mutations in susceptible loci which are recognized as valuable prognostic markers in chronic lymphocytic leukemia (CLL) and B cell lymphoma (BCL). Alongside, robust genetic manipulations facilitated the generation of preclinical mouse models to validate mutations associated with poor prognosis and refractory B cell malignancies. Taken together, these studies identified new prognostic markers that could achieve characteristics of precision biomarkers for molecular diagnosis. On the contrary, the idea of augmented B cell antigen receptor (BCR) signaling as a transforming cue has somewhat receded despite the efficacy of Btk and Syk inhibitors. Recent studies from several research groups pointed out that acquired mutations in BCR components serve as faithful biomarkers, which become important for precision diagnostics and therapy, due to their relevant role in augmented BCR signaling and CLL pathogenesis. For example, we showed that expression of a single point mutated immunoglobulin light chain (LC) recombined through the variable gene segment IGLV3-21, named IGLV3-21R110, marks severe CLL cases. In this perspective, we summarize the molecular mechanisms fine-tuning B cell transformation, focusing on immunoglobulin point mutations and recurrent mutations in tumor suppressors. We present a stochastic model for gain-of-autonomous BCR signaling and subsequent neoplastic transformation. Of note, additional mutational analyses on immunoglobulin heavy chain (HC) derived from non-subset #2 CLL IGLV3-21R110 cases endorses our perspective. Altogether, we propose a model of malignant transformation in which the augmented BCR signaling creates a conducive platform for the appearance of transforming mutations.


2021 ◽  
Vol 2 ◽  
Author(s):  
Christine M. Jones ◽  
Ilinca I. Ciubotariu ◽  
Mbanga Muleba ◽  
James Lupiya ◽  
David Mbewe ◽  
...  

Residual vector populations that do not come in contact with the most frequently utilized indoor-directed interventions present major challenges to global malaria eradication. Many of these residual populations are mosquito species about which little is known. As part of a study to assess the threat of outdoor exposure to malaria mosquitoes within the Southern and Central Africa International Centers of Excellence for Malaria Research, foraging female anophelines were collected outside households in Nchelenge District, northern Zambia. These anophelines proved to be more diverse than had previously been reported in the area. In order to further characterize the anopheline species, sequencing and phylogenetic approaches were utilized. Anopheline mosquitoes were collected from outdoor light traps, morphologically identified, and sent to Johns Hopkins Bloomberg School of Public Health for sequencing. Sanger sequencing from 115 field-derived samples yielded mitochondrial COI sequences, which were aligned with a homologous 488 bp gene segment from known anophelines (n = 140) retrieved from NCBI. Nuclear ITS2 sequences (n = 57) for at least one individual from each unique COI clade were generated and compared against NCBI’s nucleotide BLAST database to provide additional evidence for taxonomical identity and structure. Molecular and morphological data were combined for assignment of species or higher taxonomy. Twelve phylogenetic groups were characterized from the COI and ITS2 sequence data, including the primary vector species Anopheles funestus s.s. and An. gambiae s.s. An unexpectedly large proportion of the field collections were identified as An. coustani and An. sp. 6. Six phylogenetic groups remain unidentified to species-level. Outdoor collections of anopheline mosquitoes in areas frequented by people in Nchelenge, northern Zambia, proved to be extremely diverse. Morphological misidentification and underrepresentation of some anopheline species in sequence databases confound efforts to confirm identity of potential malaria vector species. The large number of unidentified anophelines could compromise the malaria vector surveillance and malaria control efforts not only in northern Zambia but other places where surveillance and control are focused on indoor-foraging and resting anophelines. Therefore, it is critical to continue development of methodologies that allow better identification of these populations and revisiting and cleaning current genomic databases.


Pathogens ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1583
Author(s):  
Chithra C. Sreenivasan ◽  
Zizhang Sheng ◽  
Dan Wang ◽  
Feng Li

Other than genome structure, influenza C (ICV), and D (IDV) viruses with seven-segmented genomes are biologically different from the eight-segmented influenza A (IAV), and B (IBV) viruses concerning the presence of hemagglutinin–esterase fusion protein, which combines the function of hemagglutinin and neuraminidase responsible for receptor-binding, fusion, and receptor-destroying enzymatic activities, respectively. Whereas ICV with humans as primary hosts emerged nearly 74 years ago, IDV, a distant relative of ICV, was isolated in 2011, with bovines as the primary host. Despite its initial emergence in swine, IDV has turned out to be a transboundary bovine pathogen and a broader host range, similar to influenza A viruses (IAV). The receptor specificities of ICV and IDV determine the host range and the species specificity. The recent findings of the presence of the IDV genome in the human respiratory sample, and high traffic human environments indicate its public health significance. Conversely, the presence of ICV in pigs and cattle also raises the possibility of gene segment interactions/virus reassortment between ICV and IDV where these viruses co-exist. This review is a holistic approach to discuss the ecology of seven-segmented influenza viruses by focusing on what is known so far on the host range, seroepidemiology, biology, receptor, phylodynamics, species specificity, and cross-species transmission of the ICV and IDV.


2021 ◽  
Author(s):  
Michelle Wille ◽  
Victoria Grillo ◽  
Silvia Ban de Gouvea Pedroso ◽  
Graham W. Burgess ◽  
Allison Crawley ◽  
...  

Most of our understanding of the ecology and evolution of avian influenza A virus (AIV) in wild birds is derived from studies conducted in the northern hemisphere on waterfowl, with a substantial bias towards dabbling ducks. However, relevant environmental conditions and patterns of avian migration and reproduction are substantially different in the southern hemisphere. Through the sequencing and analysis of 333 unique AIV genomes collected from wild birds collected over 15 years we show that Australia is a global sink for AIV diversity and not integrally linked with the Eurasian gene pool. Rather, AIV are infrequently introduced to Australia, followed by decades of isolated circulation and eventual extinction. The number of co-circulating viral lineages varies per subtype. AIV haemagglutinin (HA) subtypes that are rarely identified at duck-centric study sites (H8-12) had more detected introductions and contemporary co-circulating lineages in Australia. Combined with a lack of duck migration beyond the Australian-Papuan region, these findings suggest introductions by long-distance migratory shorebirds. In addition, we found no evidence of directional or consistent patterns in virus movement across the Australian continent. This feature corresponds to patterns of bird movement, whereby waterfowl have nomadic and erratic rainfall-dependant distributions rather than consistent intra-continental migratory routes. Finally, we detected high levels of virus gene segment reassortment, with a high diversity of AIV genome constellations across years and locations. These data, in addition to those from other studies in Africa and South America, clearly show that patterns of AIV dynamics in the Southern Hemisphere are distinct from those in the temperate north.


2021 ◽  
Author(s):  
Adria Aterido ◽  
Maria Lopez-Lasanta ◽  
Francisco Blanco ◽  
Antonio Juan-Mas ◽  
Maria Luz Garcia-Vivar ◽  
...  

Rheumatoid arthritis (RA) is an immune-mediated inflammatory disease characterized by a defective adaptive immune receptor repertoire (AIRR) that fails to distinguish self from non-self antigens. The AIRR is vast, encompassing four T cell receptor (TCR) and three B cell receptor (BCR) chains, each of which displays an extraordinary amino acid sequence variability in the antigen-binding site. How the concerted action of T and B cell clones is associated with the development and clinical evolution of immune-mediated diseases is still not known. Using a new immunosequencing technology that allows the unbiased amplification of the seven receptor chains, we conducted an in-depth quantitative analysis of the seven-receptor chain variability in RA. Compared to healthy controls, the AIRR in RA was found to be characterized by a lower BCR diversity, the depletion of highly similar BCR clones, an isotype-specific signature as well as a skewed IGL chain and gene segment usage. A predictor based on quantitative multi-chain AIRR information was able to accurately predict disease, including the elusive seronegative subset of RA patients. AIRR features of the seven immune receptor chains were also different between patients with distinct clinically relevant phenotypes. Incorporating HLA variation data, we were able to identify the TCR clones that are specifically associated with disease risk variants. The longitudinal analysis of the AIRR revealed that treatment with Tumor Necrosis Factor (TNF) inhibitors selectively restores the diversity of B cell clones in RA patients by reducing the frequency of clones with a similar biochemical profile. The biochemical properties of the TNFi-modulated clones were also found to differ between responders and non-responders, supporting a different antigenic reactivity in the B cell compartment of these two groups of RA patients. Our comprehensive analysis of the TCR and BCR repertoire reveals a complex T and B cell architecture in RA, and provides the basis for precision medicine strategies based on the highly informative features of the adaptive immune response.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jonathan Crider ◽  
Sylvie M. A. Quiniou ◽  
Kristianna L. Felch ◽  
Kurt Showmaker ◽  
Eva Bengtén ◽  
...  

The complete germline repertoires of the channel catfish, Ictalurus punctatus, T cell receptor (TR) loci, TRAD, TRB, and TRG were obtained by analyzing genomic data from PacBio sequencing. The catfish TRB locus spans 214 kb, and contains 112 TRBV genes, a single TRBD gene, 31 TRBJ genes and two TRBC genes. In contrast, the TRAD locus is very large, at 1,285 kb. It consists of four TRDD genes, one TRDJ gene followed by the exons for TRDC, 125 TRAJ genes and the exons encoding the TRAC. Downstream of the TRAC, are 140 TRADV genes, and all of them are in the opposite transcriptional orientation. The catfish TRGC locus spans 151 kb and consists of four diverse V-J-C cassettes. Altogether, this locus contains 15 TRGV genes and 10 TRGJ genes. To place our data into context, we also analyzed the zebrafish TR germline gene repertoires. Overall, our findings demonstrated that catfish possesses a more restricted repertoire compared to the zebrafish. For example, the 140 TRADV genes in catfish form eight subgroups based on members sharing 75% nucleotide identity. However, the 149 TRAD genes in zebrafish form 53 subgroups. This difference in subgroup numbers between catfish and zebrafish is best explained by expansions of catfish TRADV subgroups, which likely occurred through multiple, relatively recent gene duplications. Similarly, 112 catfish TRBV genes form 30 subgroups, while the 51 zebrafish TRBV genes are placed into 36 subgroups. Notably, several catfish and zebrafish TRB subgroups share ancestor nodes. In addition, the complete catfish TR gene annotation was used to compile a TR gene segment database, which was applied in clonotype analysis of an available gynogenetic channel catfish transcriptome. Combined, the TR annotation and clonotype analysis suggested that the expressed TRA, TRB, and TRD repertoires were generated by different mechanisms. The diversity of the TRB repertoire depends on the number of TRBV subgroups and TRBJ genes, while TRA diversity relies on the many different TRAJ genes, which appear to be only minimally trimmed. In contrast, TRD diversity relies on nucleotide additions and the utilization of up to four TRDD segments.


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