ORESTIS NOUSIAS

Dr. ORESTIS NOUSIAS

orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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3 June 2025 in Nature Ecology & Evolution
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Journal Article
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ONORESTIS NOUSIAS
ORESTIS NOUSIAS
MMMark McCauley
Mark McCauley
MSMaximilian R. Stammnitz
Maximilian R. Stammnitz
JFJessica A. Farrell
Jessica A. Farrell
SKSamantha A. Koda
Samantha A. Koda
DDDavid Duffy
David Duffy
Biodiversity and its associated genetic diversity are being lost at an unprecedented rate. Simultaneously, the distributions of flora, fauna, fungi, microbes and pathogens are rapidly changing. Novel technology can help to capture and record genetic diversity before it is lost and to measure population shifts and pathogen distributions. Here we report the rapid application of shotgun long-read environmental DNA (eDNA) analysis for non-invasive biodiversity, genetic diversity and pathogen assessments from air. We also compared air eDNA with water and soil eDNA. Coupling long-read sequencing with established cloud-based biodiversity pipelines enabled a 2-day turnaround from airborne sample collection to completed analysis by a single investigator. To determine the full utility of airborne eDNA, we also conducted a local bioinformatic analysis and deep short-read shotgun sequencing. From outdoor air eDNA alone, comprehensive genetic analysis was performed, including population genetics (phylogenetic placement) of a charismatic mammal (bobcat, Lynx rufus) and a venomous spider (golden silk orb weaver, Trichonephila clavipes), and haplotyping humans (Homo sapiens) from natural complex community settings, such as subtropical forests and temperate locations. The rich datasets also enabled deeper analysis of specific species and genomic regions of interest, including viral variant calling, human variant analysis and antimicrobial resistance gene surveillance from airborne DNA. Our results highlight the speed, versatility and specificity of pan-biodiversity monitoring via non-invasive eDNA sampling using current benchtop/portable and cloud-based approaches. Furthermore, they reveal the future feasibility of scaling down (equipment and temporally) these approaches for near real-time analysis. Together these approaches can enable rapid simultaneous detection of all life and its genetic diversity from air, water and sediment samples for unbiased non-targeted information-rich genomics-empowered (1) biodiversity monitoring, (2) population genetics, (3) pathogen and disease-vector genomic surveillance, (4) allergen and narcotic surveillance, (5) antimicrobial resistance surveillance and (6) bioprospecting.

1 February 2023 in bioRxiv
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Preprint
Open access
XFXuehuan Feng
Xuehuan Feng
JZJinfang Zheng
Jinfang Zheng
IIIker Irisarri
Iker Irisarri
HYHuihui Yu
Huihui Yu
BZBo Zheng
Bo Zheng
YYYanbin Yin
Yanbin Yin
The filamentous and unicellular algae of the class Zygnematophyceae are the closest algal relatives of land plants. Inferring the properties of the last common ancestor shared by these algae and land plants allows us to identify decisive traits that enabled the conquest of land by plants. We sequenced four genomes of filamentous Zygnematophyceae (three strains of Zygnema circumcarinatum and one strain of Z. cylindricum ) and generated chromosome-scale assemblies for all strains of the emerging model system Z. circumcarinatum . Comparative genomic analyses reveal expanded genes for signaling cascades, environmental response, and intracellular trafficking that we associate with multicellularity. Gene family analyses suggest that Zygnematophyceae share all the major enzymes with land plants for cell wall polysaccharide synthesis, degradation, and modifications; most of the enzymes for cell wall innovations, especially for polysaccharide backbone synthesis, were gained more than 700 million years ago. In Zygnematophyceae, these enzyme families expanded, forming co-expressed modules. Transcriptomic profiling of over 19 growth conditions combined with co-expression network analyses uncover cohorts of genes that unite environmental signaling with multicellular developmental programs. Our data shed light on a molecular chassis that balances environmental response and growth modulation across more than 600 million years of streptophyte evolution. HIGHLIGHTS: Genomes of four filamentous algae ( Zygnema ) sisters to land plants Zygnema are rich in genes for multicellular growth and environmental acclimation: signaling, lipid modification, and transport Cell wall innovations: diversification of hexameric rosette cellulose synthase in Zygnematophyceae Co-expression networks reveal conserved modules for balancing growth and acclimation

10 December 2021 in Fishes
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Journal Article
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ONORESTIS NOUSIAS
ORESTIS NOUSIAS
KTKonstantinos Tzokas
Konstantinos Tzokas
LPLeonidas Papaharisis
Leonidas Papaharisis
KEKaterina Ekonomaki
Katerina Ekonomaki
DCDimitrios Chatziplis
Dimitrios Chatziplis
CTCostas Tsigenopoulos
Costas Tsigenopoulos
This study evaluates the genetic diversity of different meagre broodstocks sampled in Greece. A multiplex of twelve microsatellite markers was used to genotype 946 fish from eleven stocks and batches used for broodstock selection, and the genetic data was used to calculate genetic population parameters as well as to investigate the genetic differentiation between stocks. The results from a relatedness analysis were used as the guiding lines for a fine-tuned and overall evaluation of the genetic distance between stocks, and the choice of candidate breeders from some of them. The approach implemented in this study uses well-established population genetics methods to evaluate the selection of breeder candidates in aquaculture commercial conditions utilizing a descriptive genetic data set based on microsatellite analyses, and to outline an efficient methodology for establishing the basis of new breeding schemes.

3 November 2024 in bioRxiv
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ONORESTIS NOUSIAS
ORESTIS NOUSIAS
FDFiona G. Duffy
Fiona G. Duffy
IDIsabelle J. Duffy
Isabelle J. Duffy
JWJenny Whilde
Jenny Whilde
DDDavid Duffy
David Duffy
As global temperatures rise, species populations and biodiversity decline, and infectious diseases emerge all at unprecedented rates, it is more vital than ever to accurately understand the current state of natural habitats. While traditional methods including direct sampling and observation have their merits, newer technologies offer additional sampling capabilities. Here, we assess the feasibility of a single assay: shotgun long-read sequencing, to monitor species eDNA from across the tree of life, from viruses to complex multicellular organisms, across a river system (mountain tributary to sea). We conducted eDNA sampling and shotgun long-read sampling from water taken from the Avoca River watercourse, Co. Wicklow, Ireland, from a mountain tributary through to the sea, and comparative nearby beach sand sampling. We report that shotgun long-read sequencing and metagenomic analysis have utility for the detection and quantification of organismal DNA present in eDNA samples, from across the tree of life, from microbes (including DNA viruses) to mammals. With this single assay we were able to simultaneously quantify differences in eDNA abundance for a broad range of biodiversity and pathogens across sites and sample types. This included human, wildlife, plant and microbial pathogens and parasites with health, agricultural and economic importance. Additionally, the generated eDNA genomic data enabled population genetic applications even from natural complex community settings, as demonstrated here for blue mussels ( Mytilus edulis ). The results demonstrate that Oxford Nanopore sequencing provides a quantitative approach for river biodiversity, pollution and environmental health monitoring. This method is more cost-effective and requires less laboratory preparation time or molecular expertise (barcode/primer design) than alternative biodiversity eDNA approaches (e.g. metabarcoding or qPCR). Shotgun analysis approaches will also benefit from the continual expansion of reference genome databases, for environmental, evolutionary and medical reasons, among others. Computation, cloud and artificial intelligence (AI) tools (such as the cloud-based analyses utilized here) can analyze shotgun sequencing eDNA data in a matter of hours and can be used by conservation practitioners, environmentalists and public health personnel without the need for coding or in-depth bioinformatics skills. The proven citizen/community scientist applicability and ease of eDNA sampling may further revolutionize and democratize biodiversity research, conservation surveillance, and environmental health monitoring. Long-read shotgun sequencing of eDNA offers the means to assess whole ecosystems, and the ecological, trophic, and host-pathogen interactions occurring within them.

26 February 2024 in Plants
Verified
Journal Article
Open access
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TLTang Li
Tang Li
JZJinfang Zheng
Jinfang Zheng
ONORESTIS NOUSIAS
ORESTIS NOUSIAS
YYYuchen Yan
Yuchen Yan
LMLyndel W. Meinhardt
Lyndel W. Meinhardt
YYYanbin Yin
Yanbin Yin
Annona cherimola (cherimoya) is a species renowned for its delectable fruit and medicinal properties. In this study, we developed a chromosome-level genome assembly for the cherimoya ‘Booth’ cultivar from the United States. The genome assembly has a size of 794 Mb with a N50 = 97.59 Mb. The seven longest scaffolds account for 87.6% of the total genome length, which corresponds to the seven pseudo-chromosomes. A total of 45,272 protein-coding genes (≥30 aa) were predicted with 92.9% gene content completeness. No recent whole genome duplications were identified by an intra-genome collinearity analysis. Phylogenetic analysis supports that eudicots and magnoliids are more closely related to each other than to monocots. Moreover, the Magnoliales was found to be more closely related to the Laurales than the Piperales. Genome comparison revealed that the ‘Booth’ cultivar has 200 Mb less repeats than the Spanish cultivar ‘Fino de Jete’, despite their highly similar (>99%) genome sequence identity and collinearity. These two cultivars were diverged during the early Pleistocene (1.93 Mya), which suggests a different origin and domestication of the cherimoya. Terpene/terpenoid metabolism functions were found to be enriched in Magnoliales, while TNL (Toll/Interleukin-1-NBS-LRR) disease resistance gene has been lost in Magnoliales during evolution. We have also identified a gene cluster that is potentially responsible for the biosynthesis of acetogenins, a class of natural products found exclusively in Annonaceae. The cherimoya genome provides an invaluable resource for supporting characterization, conservation, and utilization of Annona genetic resources.