ORCID Profile
0000-0001-7114-7710
Current Organisation
University of Queensland Institute for Molecular Bioscience
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Publisher: MDPI AG
Date: 13-10-2022
DOI: 10.3390/V14102248
Abstract: Dengue virus (DENV) is the world’s most common arboviral infection, with an estimated 3.9 million people at risk of the infection, 100 million symptomatic cases and 10,000 deaths per year. Current diagnosis for DENV includes the use of molecular methods, such as polymerase chain reaction, which can be costly for routine use. The near-infrared spectroscopy (NIR) technique is a high throughput technique that involves shining a beam of infrared light on a biological s le, collecting a reflectance spectrum, and using machine learning algorithms to develop predictive algorithms. Here, we used NIR to detect DENV1 artificially introduced into whole blood, plasma, and serum collected from human donors. Machine learning algorithms were developed using artificial neural networks (ANN) and the resultant models were used to predict independent s les. DENV in plasma s les was detected with an overall accuracy, sensitivity, and specificity of 90% (N = 56), 88.5% (N = 28) and 92.3% (N = 28), respectively. However, a predictive sensitivity of 33.3% (N = 16) and 80% (N = 10) and specificity of 46.7% (N = 16) and 32% (N = 10) was achieved for detecting DENV1 in whole blood and serum s les, respectively. DENV1 peaks observed at 812 nm and 819 nm represent C-H stretch, peaks at 1130–1142 nm are related to methyl group and peaks at 2127 nm are related to saturated fatty groups. Our findings indicate the potential of NIR as a diagnostic tool for DENV, however, further work is recommended to assess its sensitivity for detecting DENV in people naturally infected with the virus and to determine its capacity to differentiate DENV serotypes and other arboviruses.
Publisher: Springer Science and Business Media LLC
Date: 20-01-2016
Publisher: Wiley
Date: 22-08-2015
DOI: 10.1111/PBI.12240
Abstract: Despite being a major international crop, our understanding of the wheat genome is relatively poor due to its large size and complexity. To gain a greater understanding of wheat genome ersity, we have identified single nucleotide polymorphisms between 16 Australian bread wheat varieties. Whole-genome shotgun Illumina paired read sequence data were mapped to the draft assemblies of chromosomes 7A, 7B and 7D to identify more than 4 million intervarietal SNPs. SNP density varied between the three genomes, with much greater density observed on the A and B genomes than the D genome. This variation may be a result of substantial gene flow from the tetraploid Triticum turgidum, which possesses A and B genomes, during early co-cultivation of tetraploid and hexaploid wheat. In addition, we examined SNP density variation along the chromosome syntenic builds and identified genes in low-density regions which may have been selected during domestication and breeding. This study highlights the impact of evolution and breeding on the bread wheat genome and provides a substantial resource for trait association and crop improvement. All SNP data are publically available on a generic genome browser GBrowse at www.wheatgenome.info.
Publisher: Elsevier BV
Date: 2019
Publisher: American Association for the Advancement of Science (AAAS)
Date: 17-08-2018
Abstract: Wheat is one of the major sources of food for much of the world. However, because bread wheat's genome is a large hybrid mix of three separate subgenomes, it has been difficult to produce a high-quality reference sequence. Using recent advances in sequencing, the International Wheat Genome Sequencing Consortium presents an annotated reference genome with a detailed analysis of gene content among subgenomes and the structural organization for all the chromosomes. Ex les of quantitative trait mapping and CRISPR-based genome modification show the potential for using this genome in agricultural research and breeding. Ramírez-González et al. exploited the fruits of this endeavor to identify tissue-specific biased gene expression and coexpression networks during development and exposure to stress. These resources will accelerate our understanding of the genetic basis of bread wheat. Science , this issue p. eaar7191 see also p. eaar6089
Publisher: Elsevier BV
Date: 2019
DOI: 10.1016/J.NBT.2018.03.003
Abstract: Bread wheat (Triticum aestivum L.) is a staple food for a significant part of the world's population. The growing demand on its production can be satisfied by improving yield and resistance to biotic and abiotic stress. Knowledge of the genome sequence would aid in discovering genes and QTLs underlying these traits and provide a basis for genomics-assisted breeding. Physical maps and BAC clones associated with them have been valuable resources from which to generate a reference genome of bread wheat and to assist map-based gene cloning. As a part of a joint effort coordinated by the International Wheat Genome Sequencing Consortium, we have constructed a BAC-based physical map of bread wheat chromosome arm 7DS consisting of 895 contigs and covering 94% of its estimated length. By anchoring BAC contigs to one radiation hybrid map and three high resolution genetic maps, we assigned 73% of the assembly to a distinct genomic position. This map integration, interconnecting a total of 1713 markers with ordered and sequenced BAC clones from a minimal tiling path, provides a tool to speed up gene cloning in wheat. The process of physical map assembly included the integration of the 7DS physical map with a whole-genome physical map of Aegilops tauschii and a 7DS Bionano genome map, which together enabled efficient scaffolding of physical-map contigs, even in the non-recombining region of the genetic centromere. Moreover, this approach facilitated a comparison of bread wheat and its ancestor at BAC-contig level and revealed a reconstructed region in the 7DS pericentromere.
Publisher: MDPI AG
Date: 11-06-2019
Abstract: To date, several viruses of different genera have been reported to infect yam (Dioscorea spp.). The full ersity of viruses infecting yam, however, remains to be explored. High-throughput sequencing (HTS) methods are increasingly being used in the discovery of new plant viral genomes. In this study, we employed HTS on yam to determine whether any undiscovered viruses were present that would restrict the international distribution of yam germplasm. We discovered a new virus sequence present in 31 yam s les tested and have tentatively named this virus “yam virus Y” (YVY). Twenty-three of the s les in which YVY was detected showed mosaic and chlorotic leaf symptoms, but Yam mosaic virus was also detected in these s les. Complete genome sequences of two YVY viral isolates were assembled and found to contain five open reading frames (ORFs). ORF1 encodes a large replication-associated protein, ORF2, ORF3 and ORF4 constitute the putative triple gene block proteins, and ORF5 encodes a putative coat protein. Considering the species demarcation criteria of the family Betaflexiviridae, YVY should be considered as a novel virus species in the family Betaflexiviridae. Further work is needed to understand the association of this new virus with any symptoms and yield loss and its implication on virus-free seed yam production.
Publisher: MDPI AG
Date: 27-08-2012
Publisher: Wiley
Date: 05-04-2017
DOI: 10.1111/TPJ.13515
Abstract: There is an increasing understanding that variation in gene presence-absence plays an important role in the heritability of agronomic traits however, there have been relatively few studies on variation in gene presence-absence in crop species. Hexaploid wheat is one of the most important food crops in the world and intensive breeding has reduced the genetic ersity of elite cultivars. Major efforts have produced draft genome assemblies for the cultivar Chinese Spring, but it is unknown how well this represents the genome ersity found in current modern elite cultivars. In this study we build an improved reference for Chinese Spring and explore gene ersity across 18 wheat cultivars. We predict a pangenome size of 140 500 ± 102 genes, a core genome of 81 070 ± 1631 genes and an average of 128 656 genes in each cultivar. Functional annotation of the variable gene set suggests that it is enriched for genes that may be associated with important agronomic traits. In addition to variation in gene presence, more than 36 million intervarietal single nucleotide polymorphisms were identified across the pangenome. This study of the wheat pangenome provides insight into genome ersity in elite wheat as a basis for genomics-based improvement of this important crop. A wheat pangenome, GBrowse, is available at appliedbioinformatics.com.au/cgi-bin/gb2/gbrowse/WheatPan/, and data are available to download from heat_genome_databases.php.
Publisher: Wiley
Date: 24-01-2013
DOI: 10.1111/PBI.12044
Abstract: Despite the international significance of wheat, its large and complex genome hinders genome sequencing efforts. To assess the impact of selection on this genome, we have assembled genomic regions representing genes for chromosomes 7A, 7B and 7D. We demonstrate that the dispersion of wheat to new environments has shaped the modern wheat genome. Most genes are conserved between the three homoeologous chromosomes. We found differential gene loss that supports current theories on the evolution of wheat, with greater loss observed in the A and B genomes compared with the D. Analysis of intervarietal polymorphisms identified fewer polymorphisms in the D genome, supporting the hypothesis of early gene flow between the tetraploid and hexaploid. The enrichment for genes on the D genome that confer environmental adaptation may be associated with dispersion following wheat domestication. Our results demonstrate the value of applying next-generation sequencing technologies to assemble gene-rich regions of complex genomes and investigate polyploid genome evolution. We anticipate the genome-wide application of this reduced-complexity syntenic assembly approach will accelerate crop improvement efforts not only in wheat, but also in other polyploid crops of significance.
Publisher: Oxford University Press (OUP)
Date: 04-05-2011
Publisher: Wiley
Date: 2016
Publisher: MDPI AG
Date: 25-11-2013
Publisher: Springer Science and Business Media LLC
Date: 27-11-2019
DOI: 10.1007/S10142-018-0647-3
Abstract: Next-generation DNA sequencing technologies, such as RNA-Seq, currently dominate genome-wide gene expression studies. A standard approach to analyse this data requires mapping sequence reads to a reference and counting the number of reads which map to each gene. However, for many transcriptome studies, a suitable reference genome is unavailable, especially for meta-transcriptome studies which assay gene expression from mixed populations of organisms. Where a reference is unavailable, it is possible to generate a reference by the de novo assembly of the sequence reads. However, the high cost of generating high-coverage data for de novo assembly hinders this approach and more importantly the accurate assembly of such data is challenging, especially for meta-transcriptome data, and resulting assemblies frequently suffer from collapsed regions or chimeric sequences. As an alternative to the standard reference mapping approach, we have developed a k-mer-based analysis pipeline (DiffKAP) to identify differentially expressed reads between RNA-Seq datasets without the requirement for a reference. We compared the DiffKAP approach with the traditional Tophat/Cuffdiff method using RNA-Seq data from soybean, which has a suitable reference genome. We subsequently examined differential gene expression for a coral meta-transcriptome where no reference is available, and validated the results using qRT-PCR. We conclude that DiffKAP is an accurate method to study differential gene expression in complex meta-transcriptomes without the requirement of a reference genome.
Publisher: Springer US
Date: 2022
DOI: 10.1007/978-1-0716-2067-0_11
Abstract: Next-generation sequencing (NGS) technologies can generate billions of reads in a single sequencing run. However, with such high-throughput comes quality issues which have to be addressed before undertaking downstream analysis. Quality control on short reads is usually performed at default settings due to a lack of in-depth understanding of a particular software's parameters and their effect if changed on the output. Here we demonstrate how to optimize read trimming using Trimmomatic. We highlight the benefits of trimming by comparing the quality of transcripts assembled using trimmed and untrimmed reads.
Publisher: Springer US
Date: 2022
DOI: 10.1007/978-1-0716-2067-0_12
Abstract: The recent emergence of "third-generation" sequencing platforms which address shortcomings of standard short reads has allowed the resolution of complex genomic regions during genome assembly. However, sequencing costs for third-generation platforms continue to be high. Novel approaches that leverage the low cost of short-read sequencing while capturing long-range information have been developed. In this chapter, we focus on one such approach, the 10x Genomics' Chromium system. We demonstrate the assembly of the B73 maize reference genome using the Supernova assembler. We also offer suggestions on how one might improve the resulting assembly through analysis of assembly metrics.
Publisher: Public Library of Science (PLoS)
Date: 29-11-2021
DOI: 10.1371/JOURNAL.PPAT.1010120
Abstract: Horizontal gene transfer is widespread in insects bearing intracellular symbionts. Horizontally transferred genes (HTGs) are presumably involved in amino acid synthesis in sternorrhynchan insects. However, their role in insect-symbiont interactions remains largely unknown. We found symbionts Portiera , Hamiltonella and Rickettsia possess most genes involved in lysine synthesis in the whitefly Bemisia tabaci MEAM1 although their genomes are reduced. Hamiltonella maintains a nearly complete lysine synthesis pathway. In contrast, Portiera and Rickettsia require the complementation of whitefly HTGs for lysine synthesis and have lysE , encoding a lysine exporter. Furthermore, each horizontally transferred lysine gene of ten B . tabaci cryptic species shares an evolutionary origin. We demonstrated that Hamiltonella did not alter the titers of Portiera and Rickettsia or lysine gene expression of Portiera , Rickettsia and whiteflies. Hamiltonella also did not impact on lysine levels or protein localization in bacteriocytes harboring Portiera and ovaries infected with Rickettsia . Complementation with whitefly lysine synthesis HTGs rescued E . coli lysine gene knockout mutants. Silencing whitefly lysA in whiteflies harboring Hamiltonella reduced lysine levels, adult fecundity and titers of Portiera and Rickettsia without influencing the expression of Hamiltonella lysA . Furthermore, silencing whitefly lysA in whiteflies lacking Hamiltonella reduced lysine levels, adult fecundity and titers of Portiera and Rickettsia in ovarioles. Therefore, we, for the first time, demonstrated an essential amino acid lysine synthesized through HTGs is important for whitefly reproduction and fitness of both obligate and facultative symbionts, and it illustrates the mutual dependence between whitefly and its two symbionts. Collectively, this study reveals that acquisition of horizontally transferred lysine genes contributes to coadaptation and coevolution between B . tabaci and its symbionts.
Publisher: Springer Science and Business Media LLC
Date: 25-11-2015
DOI: 10.1007/S10142-014-0412-1
Abstract: Recent comparisons of the increasing number of genome sequences have revealed that variation in gene content is considerably more prevalent than previously thought. This variation is likely to have a pronounced effect on phenotypic ersity and represents a crucial target for the assessment of genomic ersity. Leptosphaeria maculans, a causative agent of phoma stem canker, is the most devastating fungal pathogen of Brassica napus (oilseed rape/canola). A number of L. maculans genes are known to be present in some isolates but lost in the others. We analyse gene content variation within three L. maculans isolates using a hybrid mapping and genome assembly approach and identify genes which are present in one of the isolates but missing in the others. In total, 57 genes are shown to be missing in at least one isolate. The genes encode proteins involved in a range of processes including oxidative processes, DNA maintenance, cell signalling and sexual reproduction. The results demonstrate the effectiveness of the method and provide new insight into genomic ersity in L. maculans.
Publisher: Springer Science and Business Media LLC
Date: 19-04-2022
DOI: 10.1186/S13100-022-00270-6
Abstract: Whiteflies are agricultural pests that cause negative impacts globally to crop yields resulting at times in severe economic losses and food insecurity. The Bemisia tabaci whitefly species complex is the most damaging in terms of its broad crop host range and its ability to serve as vector for over 400 plant viruses. Genomes of whiteflies belonging to this species complex have provided valuable genomic data however, transposable elements (TEs) within these genomes remain unexplored. This study provides the first accurate characterization of TE content within the B. tabaci species complex. This study identified that an average of 40.61% of the genomes of three whitefly species (MEAM1, MEDQ, and SSA-ECA) consists of TEs. The majority of the TEs identified were DNA transposons (22.85% average) while SINEs (0.14% average) were the least represented. This study also compared the TE content of the three whitefly genomes with three other hemipteran genomes and found significantly more DNA transposons and less LINEs in the whitefly genomes. A total of 63 TE superfamilies were identified to be present across the three whitefly species (39 DNA transposons, six LTR, 16 LINE, and two SINE). The sequences of the identified TEs were clustered which generated 5766 TE clusters. A total of 2707 clusters were identified as uniquely found within the whitefly genomes while none of the generated clusters were from both whitefly and non-whitefly TE sequences. This study is the first to characterize TEs found within different B. tabaci species and has created a standardized annotation workflow that could be used to analyze future whitefly genomes. This study is the first to characterize the landscape of TEs within the B. tabaci whitefly species complex. The characterization of these elements within the three whitefly genomes shows that TEs occupy significant portions of B. tabaci genomes, with DNA transposons representing the vast majority. This study also identified TE superfamilies and clusters of TE sequences of potential interest, providing essential information, and a framework for future TE studies within this species complex.
Publisher: Springer Science and Business Media LLC
Date: 10-03-2015
DOI: 10.1007/S00122-015-2488-Y
Abstract: We characterise the distribution of crossover and non-crossover recombination in Brassica napus and Cicer arietinum using a low-coverage genotyping by sequencing pipeline SkimGBS. The growth of next-generation DNA sequencing technologies has led to a rapid increase in sequence-based genotyping for applications including ersity assessment, genome structure validation and gene-trait association. We have established a skim-based genotyping by sequencing method for crop plants and applied this approach to genotype-segregating populations of Brassica napus and Cicer arietinum. Comparison of progeny genotypes with those of the parental in iduals allowed the identification of crossover and non-crossover (gene conversion) events. Our results identify the positions of recombination events with high resolution, permitting the mapping and frequency assessment of recombination in segregating populations.
Publisher: Wiley
Date: 23-01-2016
DOI: 10.1111/PBI.12513
Publisher: Springer Science and Business Media LLC
Date: 10-03-2021
DOI: 10.1007/S10340-021-01355-6
Abstract: Over the past three decades, highly increased whitefly ( Bemisia tabaci ) populations have been observed on the staple food crop cassava in eastern Africa and associated with ensuing viral disease pandemics and food insecurity. Increased whitefly numbers have also been observed in other key agricultural crops and weeds. Factors behind the population surges on different crops and their interrelationships are unclear, although in cassava they have been associated with specific populations within the Bemisia tabaci species complex known to infest cassava crops in Africa. This study carried out an in-depth survey to understand the distribution of B. tabaci populations infesting crops and uncultivated plant hosts in Uganda, a centre of origin for this pest complex. Whitefly s les were collected from 59 identified plant species and 25 unidentified weeds in a countrywide survey. Identities of 870 in idual adult whiteflies were determined through mitochondrial cytochrome oxidase 1 sequences (651 bp) in the 3′ barcode region used for B. tabaci systematics. Sixteen B. tabaci and five related whitefly putative species were identified based on 4.0% nucleotide ergence, of which three are proposed as novel B. tabaci putative species and four as novel closely related whitefly species. The most prevalent whiteflies were classified as B. tabaci MED-ASL (30.5% of s les), sub-Saharan Africa 1 (SSA1, 22.7%) and Bemisia Uganda1 (12.1%). These species were also indicated to be the most polyphagous occurring on 33, 40 and 25 identified plant species, respectively. Multiple (≥ 3) whitefly species occurred on specific crops (bean, eggplant, pumpkin and tomato) and weeds ( Sida acuta and Ocimum gratissimum ). These plants may have increased potential to act as reservoirs for mixed infections of whitefly-vectored viruses. Management of whitefly pest populations in eastern Africa will require an integration of approaches that consider their degree of polyphagy and a climate that enables the continuous presence of crop and uncultivated plant hosts.
Publisher: Springer Science and Business Media LLC
Date: 13-11-2017
Publisher: Springer Netherlands
Date: 07-11-2014
Publisher: Wiley
Date: 10-10-2018
DOI: 10.1111/MEC.14865
Publisher: Cold Spring Harbor Laboratory
Date: 23-12-2021
DOI: 10.1101/2021.12.22.473925
Abstract: Functional annotation assigns descriptive biological meaning to genetic sequences. Limited availability of manually curated or experimentally validated plant genes from a erse range of taxa poses a significant challenge for functional annotation in non-model organisms. Accurate computational approaches are required. We argue that recent breakthroughs in deep learning have the potential to not only narrow the functional annotation gap between non-model and model plant organisms, but also annotate and reveal novel functions even for genes with no homologs in public databases. Deep learning models were applied to functionally annotate a set of previously published differentially expressed genes. Predicted protein structures and functional annotations were generated using the AlphaFold protein structure and DeepFRI protein language inference models respectively. The resulting structures and functional annotations were validated using small molecule docking experiments. DeepFRI and AlphaFold models not only correctly annotated differentially expressed genes, but also revealed detailed mechanisms involving protein-protein interactions. Deep learning models are capable of inferring novel functions and achieving high accuracy in functional annotation. Their increased use in plant research will result in major improvements in annotations for non-model plants that are underrepresented in genome databases. We illustrate how integrating protein structure prediction, functional residue prediction, and small molecule docking can infer plausible protein-protein interactions and yield additional mechanistic insights. This approach will aid in the selection of candidate genes for further study from differential expression studies that generate large gene lists.
Location: No location found
Location: Australia
Location: United Kingdom of Great Britain and Northern Ireland
Location: Kenya
No related grants have been discovered for Paul Visendi Muhindira.