Helena Silva

Dr. Helena Silva

orcid

Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

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

Representative Publications

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12 December 2014 in BMC Genomics
Verified
Journal Article
Open access
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MRMiguel Ramos
Miguel Ramos
JCJoão Lucas Coito
João Lucas Coito
HSHelena Silva
Helena Silva
JCJorge Cunha
Jorge Cunha
MCMaria Manuela Ribeiro Costa
Maria Manuela Ribeiro Costa
MRMargarida Rocheta
Margarida Rocheta
Wild plants of Vitis closely related to the cultivated grapevine (V. v. vinifera) are believed to have been first domesticated 10,000 years BC around the Caspian Sea. V. v. vinifera is hermaphrodite whereas V. v. sylvestris is a dioecious species. Male flowers show a reduced pistil without style or stigma and female flowers present reflexed stamens with infertile pollen. V. vinifera produce perfect flowers with all functional structures. The mechanism for flower sex determination and specification in grapevine is still unknown.

16 July 2018 in Frontiers in Plant Science
Verified
Journal Article
Open access
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JCJoão L. Coito
João L. Coito
HSHelena Silva
Helena Silva
MRMiguel Ramos
Miguel Ramos
MMMiguel Montez
Miguel Montez
JCJorge Cunha
Jorge Cunha
MRMargarida Rocheta
Margarida Rocheta
The most discriminating characteristic between the cultivated Vitis vinifera subsp. vinifera and the wild-form Vitis vinifera subsp. sylvestris is their sexual system. Flowers of cultivars are mainly hermaphroditic, whereas wild plants have female and male individuals whose flowers follow a hermaphroditic pattern during early stages of development and later develop non-functional reproductive organs. In angiosperms, the basic developmental system for floral organ identity is explained by the ABCDE model. This model postulates that regulatory gene functions work in a combinatorial way to confer organ identity in each whorl. In wild Vitis nothing is known about the function and expression profile of these genes. Here we show an overall view of the temporal and spatial expression pattern of the ABCDE genes as well as the pattern of VviSUPERMAN that establishes a boundary between the stamen and the carpel whorls, in the male, female and complete flower types. The results show a similar pattern in Vitis species suggesting that the pathway leading to unisexuality acts independently and/or downstream of B- and C- function genes.

31 January 2017 in Frontiers in Plant Science
Verified
Journal Article
Open access
JCJoão L. Coito
João L. Coito
MRMiguel Ramos
Miguel Ramos
JCJorge Cunha
Jorge Cunha
HSHelena Silva
Helena Silva
SASara Amancio
Sara Amancio
MRMargarida Rocheta
Margarida Rocheta
Vitis vinifera vinifera is a hermaphrodite subspecies, while its ancestor, Vitis vinifera sylvestris, is dioecious. We have identified two genes that together allow the discrimination between male, female and hermaphrodite Vitis plants. The sex locus region on chromosome 2 was screened resulting in the discovery of a new gene, VviFSEX. The same screening revealed another gene, VviAPRT3, located in the sex region, that be used as a sex marker. Both genes are good candidates to be involved in flower sex differentiation in grapevine. To assess their role in sex specification, spatial and temporal expression analysis was performed. The expression of VviFSEX is detected in petals, stamens and carpel primordia of all flower types, making its putative function unclear; however, female plants display a single allele for this gene, while male and hermaphrodites display two alleles. On the other hand, the specific expression of VviAPRT3 in the carpel primordial of male plants suggests a possible role in the abortion of pistil structures. We propose a model to explain the carpel abortion in male flowers and the absence of stamen viability in female flowers. In addition, this work reinforces the presence of a sex locus on Vitis chromosome 2.

24 October 2016 in Plant Molecular Biology
Verified
Journal Article
Closed access
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MRMiguel Ramos
Miguel Ramos
JCJoão Lucas Coito
João Lucas Coito
JFJoana Fino
Joana Fino
JCJorge Cunha
Jorge Cunha
HSHelena Silva
Helena Silva
MRMargarida Rocheta
Margarida Rocheta

Verified
Journal Article
Open access
PDF file
HSHelena Silva
Helena Silva
RSRómulo Sobral
Rómulo Sobral
AMAlexandre P. Magalhaes
Alexandre P. Magalhaes
LMLeonor Morais-Cecilio
Leonor Morais-Cecilio
MCMaria Manuela Ribeiro Costa
Maria Manuela Ribeiro Costa
Modifications of DNA and histones, including methylation and acetylation, are critical for the epigenetic regulation of gene expression during plant development, particularly during environmental adaptation processes. However, information on the enzymes catalyzing all these modifications in trees, such as Quercus suber L., is still not available. In this study, eight DNA methyltransferases (DNA Mtases) and three DNA demethylases (DDMEs) were identified in Q. suber. Histone modifiers involved in methylation (35), demethylation (26), acetylation (8), and deacetylation (22) were also identified in Q. suber. In silico analysis showed that some Q. suber DNA Mtases, DDMEs and histone modifiers have the typical domains found in the plant model Arabidopsis, which might suggest a conserved functional role. Additional phylogenetic analyses of the DNA and histone modifier proteins were performed using several plant species homologs, enabling the classification of the Q. suber proteins. A link between the expression levels of each gene in different Q. suber tissues (buds, flowers, acorns, embryos, cork, and roots) with the functions already known for their closest homologs in other species was also established. Therefore, the data generated here will be important for future studies exploring the role of epigenetic regulators in this economically important species.

9 April 2024 in Cells
Verified
Journal Article
Open access
PDF file
BCBruna Coelho-Ribeiro
Bruna Coelho-Ribeiro
HSHelena Silva
Helena Silva
BSBelém Sampaio-Marques
Belém Sampaio-Marques
AFAlexandra G. Fraga
Alexandra G. Fraga
OAOlga Azevedo
Olga Azevedo
Paula LudovicoPaula Ludovico
Paula Ludovico
Fabry Disease (FD) is one of the most prevalent lysosomal storage disorders, resulting from mutations in the GLA gene located on the X chromosome. This genetic mutation triggers glo-botriaosylceramide (Gb-3) buildup within lysosomes, ultimately impairing cellular functions. Given the role of lysosomes in immune cell physiology, FD has been suggested to have a profound impact on immunological responses. During the past years, research has been focusing on this topic, and pooled evidence strengthens the hypothesis that Gb-3 accumulation potentiates the production of pro-inflammatory mediators, revealing the existence of an acute inflammatory process in FD that possibly develops to a chronic state due to stimulus persistency. In parallel, extracellular vesicles (EVs) have gained attention due to their function as intercellular communicators. Considering EVs’ capacity to convey cargo from parent to distant cells, they emerge as potential inflammatory intermediaries capable of transporting cytokines and other immunomodulatory molecules. In this review, we revisit the evidence underlying the association between FD and altered immune responses and explore the potential of EVs to function as inflammatory vehicles.