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51.
52.
Translocation of mtDNA into the nuclear genome, also referred to as numt, was first reported in the domestic cat (Felis catus) by Lopez et al. (1994). The Lopez-numt consisted of a translocation of 7.9 kbp of mtDNA that inserted into the domestic cat chromosome D2 around 1.8 million years ago. More than a decade later, the release of the domestic cat whole-genome shotgun sequences (1.9x coverage) provides the resource to obtain more comprehensive insight into the extent of mtDNA transfer over time in the domestic cat genome. MegaBLAST searches revealed that the cat genome harbors a wide variety of numts (298 320 bp), one-third of which likely correspond to the Lopez-numt tandem repeat, whereas the remaining numts are probably derived from multiple independent insertions, which in some cases were followed by segmental duplication after insertion in the nucleus. Numts were detected across most cat chromosomes, but the number of numts assigned to chromosomes is underestimated due to the relatively high number of numt sequences with insufficient flanking sequence to map. The catalog of cat numts provides a valuable resource for future studies in Felidae species, including its use as a tool to avoid numt contaminations that may confound population genetics and phylogenetic studies. 相似文献
53.
Otters and fish farms in the Sado estuary: ecological and socio-economic basis of a conflict 总被引:2,自引:0,他引:2
Dália Freitas J. Gomes T. Sales Luis L. Madruga C. Marques G. Baptista L. M. Rosalino P. Antunes R. Santos M. Santos-Reis 《Hydrobiologia》2007,587(1):51-62
The degree of conflict between otter conservation and fish farming was assessed at Sado estuary (SW Portugal), using ecological
(otter visiting rates to fish farms and consumption of commercial fish) and socio-economic (past and current instruments and
policies addressing the conflict and a social impact assessment, including a discourse analysis of relevant stakeholders)
parameters. The study concerned 14 fish farms producing Sparus aurata, Dicentrarchus labrax, Solea senegalensis and Solea solea. Results indicate high visiting rates in most fish farms (average: 76%), although in only 29%, species stocked were the most
consumed prey. Other marine species and freshwater prey were the basis of otter diet in the remaining fish farms. The conflict
is quite consensual among most fish farmers, and the results indicate that the perceived conflict by fish farmers has an ecological
basis, although there are large gaps between effective and perceived predation. No specific instruments exist in Portugal
to address the conflict, but some not specifically targeted can have an effect (e.g. species protection legislation and aquaculture
licensing), although with limitations to effectively contribute to its mitigation (e.g. lack of enforcement and supervision).
Formulating and assessing solutions is the following step, using a participatory approach to the development and evaluation
of mitigation/compensation strategies, capable of providing an effective reconciliation of the conflict.
相似文献
M. Santos-ReisEmail: |
54.
Radiolabeled somatostatin analogues have been successfully used for targeted radiotherapy and for imaging of somatostatin receptor (sst1-5)-positive tumors. Nevertheless, these analogues are subject to improving their tumor-to-nontarget ratio to enhance their diagnostic or therapeutic properties, preventing nephrotoxicity. In order to understand the influence of lipophilicity and charge on the pharmacokinetic profile of [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA)]-somatostatin-based radioligands such as [DOTA,1-Nal3]-octreotide (DOTA-NOC), different spacers (X) based on 8-amino-3,6-dioxaoctanoic acid (PEG2), 15-amino-4,7,10,13-tetraoxapentadecanoic acid (PEG4), N-acetyl glucosamine (GlcNAc), triglycine, beta-alanine, aspartic acid, and lysine were introduced between the chelator DOTA and the peptide NOC. All DOTA-X-NOC conjugates were synthesized by Fmoc solid-phase synthesis. The partition coefficient (log D) at pH = 7.4 indicated that higher hydrophilicity than [111In-DOTA]-NOC was achieved with the introduction of the mentioned spacers, except with triglycine and beta-alanine. The high affinity of [InIII-DOTA]-NOC for human sst2 (hsst2) was preserved with the structural modifications, while an overall drop for hsst3 affinity was observed, except in the case of [InIII-DOTA]-beta-Ala-NOC. The new conjugates preserved the good affinity for hsst5, except for [InIII-DOTA]-Asn(GlcNAc)-NOC, which showed decreased affinity. A significant 1.2-fold improvement in the specific internalization rate in AR4-2J rat pancreatic tumor cells (sst2 receptor expression) at 4 h was achieved with the introduction of Asp as a spacer in the parent compound. In sst3-expressing HEK cells, the specific internalization rate at 4 h for [111In-DOTA]-NOC (13.1% +/- 0.3%) was maintained with [111In-DOTA]-beta-Ala-NOC (14.0% +/- 1.8%), but the remaining derivatives showed <2% specific internalization. Biodistribution studies were performed with Lewis rats bearing the AR4-2J rat pancreatic tumor. In comparison to [111In-DOTA]-NOC (2.96% +/- 0.48% IA/g), the specific uptake in the tumor at 4 h p.i. was significantly improved for the 111In-labeled sugar analogue (4.17% +/- 0.46% IA/g), which among all the new derivatives presented the best tumor-to-kidney ratio (1.9). 相似文献
55.
Cíntia Júnia Monteiro Suianne Letícia Antunes Mota Lívia de Figueiredo Diniz Maria Terezinha Bahia Karen CM Moraes 《Memórias do Instituto Oswaldo Cruz》2015,110(8):996-1002
Chagas disease, which is caused by the intracellular protozoanTrypanosoma
cruzi, is a serious health problem in Latin America. The heart is one of
the major organs affected by this parasitic infection. The pathogenesis of tissue
remodelling, particularly regarding cardiomyocyte behaviour after parasite infection,
and the molecular mechanisms that occur immediately following parasite entry into
host cells are not yet completely understood. Previous studies have reported that the
establishment of parasitism is connected to the activation of the
phosphatidylinositol-3 kinase (PI3K), which controls important steps in cellular
metabolism by regulating the production of the second messenger
phosphatidylinositol-3,4,5-trisphosphate. Particularly, the tumour suppressor PTEN is
a negative regulator of PI3K signalling. However, mechanistic details of the
modulatory activity of PTEN on Chagas disease have not been elucidated. To address
this question, H9c2 cells were infected with T. cruzi Berenice 62
strain and the expression of a specific set of microRNAs (miRNAs) were investigated.
Our cellular model demonstrated that miRNA-190b is correlated to the decrease of
cellular viability rates by negatively modulating PTEN protein expression in
T. cruzi-infected cells. 相似文献
56.
Louisy Sanches dos Santos Camila Azevedo Antunes Cintia Silva dos Santos José Augusto Adler Pereira Priscila Soares Sabbadini Maria das Gra?as de Luna Vasco Azevedo Raphael Hirata Júnior Andreas Burkovski Lídia Maria Buarque de Oliveira Asad Ana Luíza Mattos-Guaraldi 《Memórias do Instituto Oswaldo Cruz》2015,110(5):662-668
Corynebacterium diphtheriae, the aetiologic agent of diphtheria,
also represents a global medical challenge because of the existence of invasive
strains as causative agents of systemic infections. Although tellurite
(TeO32-) is toxic to most microorganisms, TeO32--resistant
bacteria, including C. diphtheriae, exist in
nature. The presence of TeO32--resistance (TeR)
determinants in pathogenic bacteria might provide selective advantages in the natural
environment. In the present study, we investigated the role of the putative
TeR determinant (CDCE8392_813gene) in the virulence
attributes of diphtheria bacilli. The disruption of CDCE8392_0813 gene expression in
the LDCIC-L1 mutant increased susceptibility to TeO32- and reactive oxygen
species (hydrogen peroxide), but not to other antimicrobial agents. The LDCIC-L1
mutant also showed a decrease in both the lethality of Caenorhabditis elegans
and the survival inside of human epithelial cells compared to wild-type
strain. Conversely, the haemagglutinating activity and adherence to and formation of
biofilms on different abiotic surfaces were not regulated through the CDCE8392_0813
gene. In conclusion, the CDCE8392_813 gene contributes to the TeR and
pathogenic potential of C. diphtheriae. 相似文献
57.
58.
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60.
Guillermín Agüero-Chapin Gisselle Pérez-Machado Reinaldo Molina-Ruiz Yunierkis Pérez-Castillo Aliuska Morales-Helguera Vítor Vasconcelos Agostinho Antunes 《Amino acids》2011,40(2):431-442
Bacteriocins are proteinaceous toxins produced and exported by both gram-negative and gram-positive bacteria as a defense
mechanism. The bacteriocin protein family is highly diverse, which complicates the identification of bacteriocin-like sequences
using alignment approaches. The use of topological indices (TIs) irrespective of sequence similarity can be a promising alternative
to predict proteinaceous bacteriocins. Thus, we present Topological Indices to BioPolymers (TI2BioP) as an alignment-free
approach inspired in both the Topological Substructural Molecular Design (TOPS-MODE) and Markov Chain Invariants for Network
Selection and Design (MARCH-INSIDE) methodology. TI2BioP allows the calculation of the spectral moments as simple TIs to seek
quantitative sequence-function relationships (QSFR) models. Since hydrophobicity and basicity are major criteria for the bactericide
activity of bacteriocins, the spectral moments (HPμ
k
) were derived for the first time from protein artificial secondary structures based on amino acid clustering into a Cartesian
system of hydrophobicity and polarity. Several orders of HPμ
k
characterized numerically 196 bacteriocin-like sequences and a control group made up of 200 representative CATH domains.
Subsequently, they were used to develop an alignment-free QSFR model allowing a 76.92% discrimination of bacteriocin proteins
from other domains, a relevant result considering the high sequence diversity among the members of both groups. The model
showed a prediction overall performance of 72.16%, detecting specifically 66.7% of proteinaceous bacteriocins whereas the
InterProScan retrieved just 60.2%. As a practical validation, the model also predicted successfully the cryptic bactericide
function of the Cry 1Ab C-terminal domain from Bacillus thuringiensis’s endotoxin, which has not been detected by classical alignment methods. 相似文献