Percorrer por autor "Fonseca, C."
A mostrar 1 - 5 de 5
Resultados por página
Opções de ordenação
- Coxiella burnetii DNA detected in domestic ruminants and wildlife from PortugalPublication . Cumbassá, A.; Barahona, M.J.; Cunha, M.V.; Azorín, B.; Fonseca, C.; Rosalino, L.M.; Tilburg, J.; Hagen, F.; Santos, A.S.; Botelho, A.Coxiella burnetii is the etiological agent of Q fever or Coxiellosis, a zoonosis mainly affecting domestic ruminants. Information on the population structure and epidemiology of C. burnetii in animals is scarce in Portugal. Evidence of C. burnetti infection was sought in domestic, wild and captive animals based on the detection of bacterial DNA. Tissue samples from 152 domestic animals (cattle = 24, goats = 51, sheep = 76 and swine = 1), 55 wild carnivores (Egyptian mongoose = 45, red fox = 4, common genet = 3, weasel = 2 and European badger = 1) and 22 zoo animals (antelopes = 15, impala = 1; rhinoceros = 1, deer = 2, zebras = 2 and giraffe = 1) were screened by nested-touchdown PCR. Cloacae swabs from 19 griffon vultures were also analysed. Among the domestic ruminants, goats presented the highest prevalence of infection (23.53%), followed by cattle, (20.83%) and sheep (10.53%). C. burnetii DNA was also detected in five Egyptian mongooses and two antelopes and one giraffe. Using a 6-locus multiple-locus variable-number tandem repeat analysis (MLVA-6) six complete genotypes, T, I and CM and the first reported CN, CO and CP, were identified, respectively, in small ruminants and Egyptian mongooses. Clustering analysis of genotypes exposed four distinct groups, according to detection source, enlightening an apparent association between C. burnetii genotype and host.
- Environmental stress is the major cause of transcriptomic and proteomic changes in GM and non-GM plantsPublication . Batista, Rita; Fonseca, C.; Planchon, Sébastien; Negrão, Sónia; Renaut, Jenny; Oliveira, MargaridaThe approval of genetically modified (GM) crops is preceded by years of intensive research to demonstrate safety to humans and environment. We recently showed that in vitro culture stress is the major factor influencing proteomic differences of GM vs. non-GM plants. This made us question the number of generations needed to erase such “memory”. We also wondered about the relevance of alterations promoted by transgenesis as compared to environment-induced ones. Here we followed three rice lines (1-control, 1-transgenic and 1-negative segregant) throughout eight generations after transgenesis combining proteomics and transcriptomics, and further analyzed their response to salinity stress on the F6 generation. Our results show that: (a) differences promoted during genetic modification are mainly short-term physiological changes, attenuating throughout generations, and (b) environmental stress may cause far more proteomic/transcriptomic alterations than transgenesis. Based on our data, we question what is really relevant in risk assessment design for GM food crops.
- In vitro culture may be the major contributing factor for transgenic versus nontransgenic proteomic plant differencesPublication . Fonseca, C.; Planchon, S.; Serra, T.; Chander, S.; Saibo, N.J.M.; Renaut, J.; Oliveira, M.M.; Batista, RitaIdentification of differences between genetically modified plants and their original counterparts plays a central role in risk assessment strategy. Our main goal was to better understand the relevance of transgene presence, genetic, and epigenetic changes induced by transgene insertion, and in vitro culture in putative unintended differences between a transgenic and its comparator. Thus, we have used multiplex fluorescence 2DE coupled with MS to characterize the proteome of three different rice lines (Oryza sativa L. ssp. japonica cv. Nipponbare): a control conventional line (C), an Agrobacterium-transformed transgenic line (Ta) and a negative segregant (NSb). We observed that Ta and NSb appeared identical (with only one spot differentially abundant--fold difference ≥ 1.5), contrasting with the control (49 spots with fold difference ≥ 1.5, in both Ta and NSb vs. control). Given that in vitro culture was the only event in common between Ta and NSb, we hypothesize that in vitro culture stress was the most relevant condition contributing for the observed proteomic differences. MS protein identification support our hypothesis, indicating that Ta and NSb lines adjusted their metabolic pathways and altered the abundance of several stress related proteins in order to cope with in vitro culture.
- Portuguese study of familial dilated cardiomyopathy: the FATIMA studyPublication . Martins, E.; Silva-Cardoso, J.; Bicho, M.; Bourbon, M.; Ceia, F.; Rebocho, M.J.; Moura, B.; Fonseca, C.; Correia, M.J.; Brito, D.; Perdigão, C.; Madeira, H.; Abreu-Lima, C.Dilated cardiomyopathy (DCM) is a myocardial disease, characterized by ventricular dilatation and impaired systolic function, that in more than 30% of cases has a familial or genetic origin. Given its age-dependent penetrance, DCM frequently manifests in adults by signs or symptoms of heart failure, arrhythmias or sudden death. The predominant mode of inheritance is autosomal dominant, and in these cases mutations are identified in genes coding for cytoskeletal, sarcomeric or nuclear envelope proteins. To date, most studies aimed at molecular diagnosis of DCM have been in selected families, or in larger groups of patients, but screening for mutations in a limited number of genes. Consequently, the epidemiology of mutations in familial DCM remains unknown. There is thus a need for multicenter studies, involving screening for a wide range of mutations in several families and in cases of idiopathic DCM. The present article describes the methodology of a multicenter study, aimed at clinical and molecular characterization of familial DCM patients in the Portuguese population.
- Safer to eat transgenic than environmentally stressed plants?Publication . Batista, Rita; Planchon, S.; Fonseca, C.; Negrão, S.; Renaut, J.; Oliveira, M.M.Concerns about Biosafety of transgenic crops have led Governments to implement regulations to assess potential risks before genetically engineered crops are approved for commercialization. Each genetically modified crop regulatory approval is preceded by years of intensive research demonstrating that the crop is safe to humans, animals as well as other non-target beneficial organisms, plants and environment. In a recent study, we have demonstrated that the major factor influencing proteomic differences of transgenic vs. non-transgenic plants may be the in vitro culture stress imposed during plant genetic transformation. This study lead us to question the dimension of transgenic vs. non transgenic differences as compared with the ones we know that can happen any time, due to environmental stresses.