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Detalhes

Detalhes

  • Nome

    Nuno Fonseca
  • Cargo

    Investigador Colaborador Externo
  • Desde

    01 junho 2009
Publicações

2023

Idioblasts accumulating anticancer alkaloids in Catharanthus roseus leaves are a unique cell type

Autores
Guedes, JG; Ribeiro, R; Carqueijeiro, I; Guimaraes, AL; Bispo, C; Archer, J; Azevedo, H; Fonseca, NA; Sottomayor, M;

Publicação

Abstract
Catharanthus roseus leaves produce a range of monoterpenoid indole alkaloids (MIAs) that include low levels of the anticancer drugs vinblastine and vincristine. The MIA pathway displays a complex architecture spanning different subcellular and cell-type localizations and is under complex regulation. As a result, the development of strategies to increase the levels of the anticancer MIAs has remained elusive. The pathway involves mesophyll specialised idioblasts where the late unsolved biosynthetic steps are thought to occur. Here, protoplasts of C. roseus leaf idioblasts were isolated by fluorescence-activated cell sorting, and their differential alkaloid and transcriptomic profiles were characterised. This involved the assembly of an improved C. roseus transcriptome from short- and long-read data, IDIO+. It was observed that C. roseus mesophyll idioblasts possess a distinctive transcriptomic profile associated with protection against biotic and abiotic stresses, and indicative that this cell type is a carbon sink, in contrast with surrounding mesophyll cells. Moreover, it is shown that idioblasts are a hotspot of alkaloid accumulation, suggesting that their transcriptome may hold the keys to the in-depth understanding of the MIA pathway and the success of strategies leading to higher levels of the anticancer drugs.

2023

The leaf idioblastome of the medicinal plant Catharanthus roseus is associated with stress resistance and alkaloid metabolism

Autores
Guedes, JG; Ribeiro, R; Carqueijeiro, I; Guimaraes, AL; Bispo, C; Archer, J; Azevedo, H; Fonseca, NA; Sottomayor, M;

Publicação
JOURNAL OF EXPERIMENTAL BOTANY

Abstract
Catharanthus roseus leaves produce a range of monoterpenoid indole alkaloids (MIAs) that include low levels of the anticancer drugs vinblastine and vincristine. The MIA pathway displays a complex architecture spanning different subcellular and cell type localizations, and is under complex regulation. As a result, the development of strategies to increase the levels of the anticancer MIAs has remained elusive. The pathway involves mesophyll specialized idioblasts where the late unsolved biosynthetic steps are thought to occur. Here, protoplasts of C. roseus leaf idioblasts were isolated by fluorescence-activated cell sorting, and their differential alkaloid and transcriptomic profiles were characterized. This involved the assembly of an improved C. roseus transcriptome from short- and long-read data, IDIO+. It was observed that C. roseus mesophyll idioblasts possess a distinctive transcriptomic profile associated with protection against biotic and abiotic stresses, and indicative that this cell type is a carbon sink, in contrast to surrounding mesophyll cells. Moreover, it is shown that idioblasts are a hotspot of alkaloid accumulation, suggesting that their transcriptome may hold the key to the in-depth understanding of the MIA pathway and the success of strategies leading to higher levels of the anticancer drugs. Catharanthus mesophyll idioblasts are a hotspot of alkaloid accumulation. The idioblast transcriptome is associated with stress responses and provides a roadmap towards the increase of anticancer alkaloid levels.

2023

The InBIO barcoding initiative database: DNA barcodes of Iberian Trichoptera, documenting biodiversity for freshwater biomonitoring in a Mediterranean hotspot

Autores
Pauperio, J; Gonzalez, LM; Martinez, J; Gonzalez, M; Martins, FM; Verissimo, J; Puppo, P; Pinto, J; Chaves, C; Pinho, CJ; Grosso-Silva, JM; Quaglietta, L; Silva, TL; Sousa, P; Alves, PC; Fonseca, N; Beja, P; Ferreira, S;

Publicação
BIODIVERSITY DATA JOURNAL

Abstract
BackgroundThe Trichoptera are an important component of freshwater ecosystems. In the Iberian Peninsula, 380 taxa of caddisflies are known, with nearly 1/3 of the total species being endemic in the region. A reference collection of morphologically identified Trichoptera specimens, representing 142 Iberian taxa, was constructed. The InBIO Barcoding Initiative (IBI) Trichoptera 01 dataset contains records of 438 sequenced specimens. The species of this dataset correspond to about 37% of Iberian Trichoptera species diversity. Specimens were collected between 1975 and 2018 and are deposited in the IBI collection at the CIBIO (Research Center in Biodiversity and Genetic Resources, Portugal) or in the collection Marcos A. Gonzalez at the University of Santiago de Compostela (Spain).New informationTwenty-nine species, from nine different families, were new additions to the Barcode of Life Data System (BOLD). A success identification rate of over 80% was achieved when comparing morphological identifications and DNA barcodes for the species analysed. This encouraging step advances incorporation of informed Environmental DNA tools in biomonitoring schemes, given the shortcomings of morphological identifications of larvae and adult Caddisflies in such studies. DNA barcoding was not successful in identifying species in six Trichoptera genera: Hydropsyche (Hydropsychidae), Athripsodes (Leptoceridae), Wormaldia (Philopotamidae), Polycentropus (Polycentropodidae) Rhyacophila (Rhyacophilidae) and Sericostoma (Sericostomatidae). The high levels of intraspecific genetic variability found, combined with a lack of a barcode gap and a challenging morphological identification, rendered these species as needing additional studies to resolve their taxonomy.

2022

A Study on Burrows-Wheeler Aligner's Performance Optimization for Ancient DNA Mapping

Autores
Sarmento, C; Guimaraes, S; Kilinc, GM; Gotherstrom, A; Pires, AE; Ginja, C; Fonseca, NA;

Publicação
PRACTICAL APPLICATIONS OF COMPUTATIONAL BIOLOGY & BIOINFORMATICS, PACBB 2021

Abstract
The high levels of degradation characteristic of ancient DNA molecules severely hinder the recovery of endogenous DNA fragments and the discovery of genetic variation, limiting downstream population analyses. Optimization of read mapping strategies for ancient DNA is therefore essential to maximize the information we are able to recover from archaeological specimens. In this paper we assess Burrows-Wheeler Aligner (BWA) effectiveness for mapping of ancient DNA sequence data, comparing different sets of parameters and their effect on the number of endogenous sequences mapped and variants called. We also consider different filtering options for SNP calling, which include minimum values for depth of coverage and base quality in addition to mapping quality. Considering our results, as well as those of previous studies, we conclude that BWA-MEM is a good alternative to the current standard BWA-backtrack strategy for ancient DNA studies, especially when the computational resources are limited and time is a constraint.

2022

Author Correction: Tumour gene expression signature in primary melanoma predicts long-term outcomes

Autores
Garg, M; Couturier, D; Nsengimana, J; Fonseca, NA; Wongchenko, M; Yan, Y; Lauss, M; Jönsson, GB; Newton-Bishop, J; Parkinson, C; Middleton, MR; Bishop, DT; McDonald, S; Stefanos, N; Tadross, J; Vergara, IA; Lo, S; Newell, F; Wilmott, JS; Thompson, JF; Long, GV; Scolyer, RA; Corrie, P; Adams, DJ; Brazma, A; Rabbie, R;

Publicação
Nature Communications

Abstract