Georgios Tsiamis

Dr. Georgios Tsiamis

University of Patras, Department of Environmental Engineering
orcid

Research Focus & Metrics

Academic Career Length

16Years (2011-Present)

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

Representative Publications

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19 June 2015 in GigaScience
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AKAnna Kopf
Anna Kopf
MBMesude Bicak
Mesude Bicak
RKRenzo Kottmann
Renzo Kottmann
JSJulia Schnetzer
Julia Schnetzer
IKIvaylo Kostadinov
Ivaylo Kostadinov
FGFrank Oliver Glöckner
Frank Oliver Glöckner
Ocean Sampling Day was initiated by the EU-funded Micro B3 (Marine Microbial Biodiversity, Bioinformatics, Biotechnology) project to obtain a snapsho

22 September 2016 in Genome Biology
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Journal Article
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Alexie PapanicolaouAlexie Papanicolaou
Alexie Papanicolaou
MSMarc F Schetelig
Marc F Schetelig
PAPeter Arensburger
Peter Arensburger
PAPeter W. Atkinson
Peter W. Atkinson
JBJosh Benoit
Josh Benoit
AHAlfred M. M. Handler
Alfred M. M. Handler
The Mediterranean fruit fly (medfly), Ceratitis capitata, is a major destructive insect pest due to its broad host range, which includes hundreds of fruits and vegetables. It exhibits a unique ability to invade and adapt to ecological niches throughout tropical and subtropical regions of the world, though medfly infestations have been prevented and controlled by the sterile insect technique (SIT) as part of integrated pest management programs (IPMs). The genetic analysis and manipulation of medfly has been subject to intensive study in an effort to improve SIT efficacy and other aspects of IPM control. The 479 Mb medfly genome is sequenced from adult flies from lines inbred for 20 generations. A high-quality assembly is achieved having a contig N50 of 45.7 kb and scaffold N50 of 4.06 Mb. In-depth curation of more than 1800 messenger RNAs shows specific gene expansions that can be related to invasiveness and host adaptation, including gene families for chemoreception, toxin and insecticide metabolism, cuticle proteins, opsins, and aquaporins. We identify genes relevant to IPM control, including those required to improve SIT. The medfly genome sequence provides critical insights into the biology of one of the most serious and widespread agricultural pests. This knowledge should significantly advance the means of controlling the size and invasive potential of medfly populations. Its close relationship to Drosophila, and other insect species important to agriculture and human health, will further comparative functional and structural studies of insect genomes that should broaden our understanding of gene family evolution.

15 February 2022 in Biomolecules
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FAFatma Acheuk
Fatma Acheuk
SBShereen Basiouni
Shereen Basiouni
Awad A ShehataAwad A Shehata
Awad A Shehata
KDKatie Dick
Katie Dick
HHHaifa Hajri
Haifa Hajri
Spyridon NtougiasSpyridon Ntougias
Spyridon Ntougias
Concerning human and environmental health, safe alternatives to synthetic pesticides are urgently needed. Many of the currently used synthetic pesticides are not authorized for application in organic agriculture. In addition, the developed resistances of various pests against classical pesticides necessitate the urgent demand for efficient and safe products with novel modes of action. Botanical pesticides are assumed to be effective against various crop pests, and they are easily biodegradable and available in high quantities and at a reasonable cost. Many of them may act by diverse yet unexplored mechanisms of action. It is therefore surprising that only few plant species have been developed for commercial usage as biopesticides. This article reviews the status of botanical pesticides, especially in Europe and Mediterranean countries, deepening their active principles and mechanisms of action. Moreover, some constraints and challenges in the development of novel biopesticides are highlighted.

27 January 2022 in Microorganisms
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Elias AsimakisElias Asimakis
Elias Asimakis
Awad A ShehataAwad A Shehata
Awad A Shehata
Wolfgang EisenreichWolfgang Eisenreich
Wolfgang Eisenreich
FAFatma Acheuk
Fatma Acheuk
SLSalma Lasram
Salma Lasram
Georgios TsiamisGeorgios Tsiamis
Georgios Tsiamis
An increasing human population necessitates more food production, yet current techniques in agriculture, such as chemical pesticide use, have negative impacts on the ecosystems and strong public opposition. Alternatives to synthetic pesticides should be safe for humans, the environment, and be sustainable. Extremely diverse ecological niches and millions of years of competition have shaped the genomes of algae to produce a myriad of substances that may serve humans in various biotechnological areas. Among the thousands of described algal species, only a small number have been investigated for valuable metabolites, yet these revealed the potential of algal metabolites as bio-pesticides. This review focuses on macroalgae and microalgae (including cyanobacteria) and their extracts or purified compounds, that have proven to be effective antibacterial, antiviral, antifungal, nematocides, insecticides, herbicides, and plant growth stimulants. Moreover, the mechanisms of action of the majority of these metabolites against plant pests are thoroughly discussed. The available information demonstrated herbicidal activities via inhibition of photosynthesis, antimicrobial activities via induction of plant defense responses, inhibition of quorum sensing and blocking virus entry, and insecticidal activities via neurotoxicity. The discovery of antimetabolites also seems to hold great potential as one recent example showed antimicrobial and herbicidal properties. Algae, especially microalgae, represent a vast untapped resource for discovering novel and safe biopesticide compounds.

2 September 2019 in Genome Biology
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Geoffrey M. AttardoGeoffrey M. Attardo
Geoffrey M. Attardo
AAAdly Abd-Alla
Adly Abd-Alla
AAAlvaro Acosta-Serrano
Alvaro Acosta-Serrano
JAJames E. Allen
James E. Allen
RBRosemary Bateta
Rosemary Bateta
SASerap Aksoy
Serap Aksoy
Tsetse flies (Glossina sp.) are the vectors of human and animal trypanosomiasis throughout sub-Saharan Africa. Tsetse flies are distinguished from other Diptera by unique adaptations, including lactation and the birthing of live young (obligate viviparity), a vertebrate blood-specific diet by both sexes, and obligate bacterial symbiosis. This work describes the comparative analysis of six Glossina genomes representing three sub-genera: Morsitans (G. morsitans morsitans, G. pallidipes, G. austeni), Palpalis (G. palpalis, G. fuscipes), and Fusca (G. brevipalpis) which represent different habitats, host preferences, and vectorial capacity. Genomic analyses validate established evolutionary relationships and sub-genera. Syntenic analysis of Glossina relative to Drosophila melanogaster shows reduced structural conservation across the sex-linked X chromosome. Sex-linked scaffolds show increased rates of female-specific gene expression and lower evolutionary rates relative to autosome associated genes. Tsetse-specific genes are enriched in protease, odorant-binding, and helicase activities. Lactation-associated genes are conserved across all Glossina species while male seminal proteins are rapidly evolving. Olfactory and gustatory genes are reduced across the genus relative to other insects. Vision-associated Rhodopsin genes show conservation of motion detection/tracking functions and variance in the Rhodopsin detecting colors in the blue wavelength ranges. Expanded genomic discoveries reveal the genetics underlying Glossina biology and provide a rich body of knowledge for basic science and disease control. They also provide insight into the evolutionary biology underlying novel adaptations and are relevant to applied aspects of vector control such as trap design and discovery of novel pest and disease control strategies.

28 April 2017 in Genetics Selection Evolution
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AKAntonis Kominakis
Antonis Kominakis
AHAriadne Hager-Theodorides
Ariadne Hager-Theodorides
Evangelos ZoidisEvangelos Zoidis
Evangelos Zoidis
ASAggeliki Saridaki
Aggeliki Saridaki
GAGeorge Antonakos
George Antonakos
Georgios TsiamisGeorgios Tsiamis
Georgios Tsiamis
Body size in sheep is an important indicator of productivity, growth and health as well as of environmental adaptation. It is a composite quantitative trait that has been studied with high-throughput genomic methods, i.e. genome-wide association studies (GWAS) in various mammalian species. Several genomic markers have been associated with body size traits and genes have been identified as causative candidates in humans, dog and cattle. A limited number of related GWAS have been performed in various sheep breeds and have identified genomic regions and candidate genes that partly account for body size variability. Here, we conducted a GWAS in Frizarta dairy sheep with phenotypic data from 10 body size measurements and genotypic data (from Illumina ovineSNP50 BeadChip) for 459 ewes. The 10 body size measurements were subjected to principal component analysis and three independent principal components (PC) were constructed, interpretable as width, height and length dimensions, respectively. The GWAS performed for each PC identified 11 significant SNPs, at the chromosome level, one on each of the chromosomes 3, 8, 9, 10, 11, 12, 19, 20, 23 and two on chromosome 25. Nine out of the 11 SNPs were located on previously identified quantitative trait loci for sheep meat, production or reproduction. One hundred and ninety-seven positional candidate genes within a 1-Mb distance from each significant SNP were found. A guilt-by-association-based (GBA) prioritization analysis (PA) was performed to identify the most plausible functional candidate genes. GBA-based PA identified 39 genes that were significantly associated with gene networks relevant to body size traits. Prioritized genes were identified in the vicinity of all significant SNPs except for those on chromosomes 10 and 12. The top five ranking genes were TP53, BMPR1A, PIK3R5, RPL26 and PRKDC. The results of this GWAS provide evidence for 39 causative candidate genes across nine chromosomal regions for body size traits, some of which are novel and some are previously identified candidates from other studies (e.g. TP53, NTN1 and ZNF521). GBA-based PA has proved to be a useful tool to identify genes with increased biological relevance but it is subjected to certain limitations.