Search results for "crisp"

2021

CRISPR-Cas immune systems adapt to new threats by acquiring new spacers from invading nucleic acids such as phage genomes. However, some CRISPR-Cas loci lack genes necessary for spacer acquisition despite variation in spacer content between microbial strains. It has been suggested that such loci may use acquisition machinery from cooccurring CRISPR-Cas systems within the same strain. Here, following infection by a virulent phage with a double-stranded DNA (dsDNA) genome, we observed spacer acquisition in the native host Flavobacterium columnare that carries an acquisition-deficient CRISPR-Cas subtype VI-B system and a complete subtype II-C system. We show that the VI-B locus acquires spacer…

Mucin induces CRISPR-Cas defence in an opportunistic pathogen

2021

AbstractParasitism by bacteriophages has led to the evolution of a variety of defense mechanisms in their host bacteria. However, it is unclear what factors lead to specific defenses being deployed upon phage infection. To explore this question, we exposed the bacterial fish pathogenFlavobacterium columnareto its virulent phage V156 in the presence of a eukaryotic host signal (mucin). All tested conditions led to some level of innate immunity, but the presence of mucin led to a dramatic increase in CRISPR spacer acquisition, especially in low nutrient conditions where over 60% of colonies had obtained at least one new spacer. Additionally, we show that the presence of a competitor bacterium…

2019

So far, studies on the bacterial immune system CRISPR-Cas and its ecological and evolutionary effects have been largely limited to laboratory conditions. While providing crucial information on the constituents of CRISPR-Cas, such studies may overlook fundamental components that affect bacterial immunity in natural habitats. Translating laboratory-derived predictions to nature is not a trivial task, owing partly to the instability of natural communities and difficulties in repeated sampling. To this end, we review how aquaculture, the farming of fishes and other aquatic species, may provide suitable semi-natural laboratories for examining the role of CRISPR-Cas in phage/bacterium coevolution…

Crecimiento económico, regresión social, crispación política

2004

Otra versión del artículo "Balance de la era Aznar" (En: Le monde diplomatique - Edición Cono Sur, nº 58, abril de 2004).

Mucin induces CRISPR-Cas defense in an opportunistic pathogen

2022

It is unknown what circumstances promote particular bacterial defenses against bacterial viruses (phages). Almeida & Hoikkala et al. show that mucin, derived from mucus, greatly accelerates CRISPR-Cas defenses against phage in an opportunistic pathogen. Parasitism by bacteriophages has led to the evolution of a variety of defense mechanisms in their host bacteria. However, it is unclear what factors lead to specific defenses being deployed upon phage infection. To explore this question, we co-evolved the bacterial fish pathogen Flavobacterium columnare and its virulent phage V156 in presence and absence of a eukaryotic host signal (mucin) for sixteen weeks. The presence of mucin leads to a …

Modulação gênica em embriões humanos

2018

O recente implemento de moderna tecnologia -CRISPR/Cas9- possibilitou o avanço inquestionável da edição gênica em linhagem germinativa humana, seja por meio da manipulação de células precursoras de gametas, células tronco pluripotentes, gametas ou, até mesmo, de embriões. Mesmo levando em conta os benefícios terapêuticos preventivos demonstrados nas pesquisas básicas e préclínicas em embriões humanos, tais investigações encontram barreiras de aceitação em todo o mundo. Tal situação exige mudança de atitude no sentido de incrementar o debate em torno da aplicabilidade dessas novas tecnologias. Assim, a adequação das atuais regulamentações faz-se necessária e deve incluir a superação dos desa…

Genetic determinants of ATR inhibitor sensitivity and resistance in Gastric Cancer

2019

Synthetic lethal approaches in identifying genetic determinants of drug response is a powerful method in selecting patents for targeted cancer therapies. Ataxia-Telangiectasia Mutated (ATM) and Rad3-related protein kinase (ATR) is a valuable target to inhibit the DNA damage repair (DDR) pathway, that has been shown to be particularly effective in cancer cells harbouring other DDR defects, including truncating mutations in ARID1A, found in the 20% of gastric cancer (GC) patients. Although ATR inhibitors (ATRi) are emerging as promising cancer therapies, resistance mechanisms inevitably arise from these drugs as monotherapy, emphasising the importance of identifying genetic determinants of re…

Inactivation of peroxisomal ABC transporters, ABCD1 and ABCD2 in BV-2 microglial cells : Towards a better understanding of X-linked adrenoleukodystro…

2018

X-linked adrenoleukodystrophy (X-ALD) is a severe neurodegenerative disorder characterized by very-long-chain fatty acid (VLCFA) accumulation resulting from a peroxisomal β-oxidation defect. The disease is caused by mutations in the ABCD1 gene, which encodes for a peroxisomal half ABC transporter predicted, like its closest homologue ABCD2, to participate in the entry of VLCFA-CoA into the peroxisome, the unique site of their β-oxidation. Progress in understanding the physiopathogenesis of X-ALD suffers from the lack of appropriate cell and animal models. Since peroxisomal defects in microglia seem to be a key element of the onset of the disease, we generated four microglial cell lines unab…

The first glimpse of the endometrial microbiota in early pregnancy

2020

Investigation of the microbial community in the female reproductive tract with the use of sequencing techniques has revealed that endometrial samples obtained through a transvaginal catheter are dominated by Lactobacillus species. Dysbiotic changes in the endometrial microbiota may be associated with implantation failure or early spontaneous abortion in patients who undergo assisted reproductive technology treatment. Whether or not there is an endometrial microbiota in early pregnancy is unknown. Herein we describe, the human endometrial microbiota in a patient who subsequently had an 8th week spontaneous clinical miscarriage with euploid embryos in the next cycle and, for the first time, d…

The «Painted» Hypogeum of Crispia Salvia (Marsala-TP) ‒ 2nd Century C.E. Preliminary Anthropological and Archaeological Report of Tomb 3 and Tomb 4

2021

Summary ― The «Painted Hypogeum of Crispia Salvia» is the most important monument of the ancient Punic-Roman necropolis of Lilibeo (today's Marsala). It is the only known paradigmatic example in Sicily of pictorial wall decoration. Iulius Demetrius commissioned the monument in memory of his wife Crispia Salvia, a noblewoman descended from two very important Sicilian families. Here we report on a preliminary anthropological study of Tombs 3 and 4 (Crispia Salvia and Iulius Demetrius). We integrated the historical-cultural context with the osteological data. The results combining laboratory and archaeological research confirm the presence of two high-ranking individuals characterized by condi…