Search results for "Centro"

Manganese overload affects p38 MAPK phosphorylation and metalloproteinase activity during sea urchin embryonic development.

2014

Abstract In the marine environment, manganese represents a potential emerging contaminant, resulting from an increased production of manganese-containing compounds. In earlier reports we found that the exposure of Paracentrotus lividus sea urchin embryos to manganese produced phenotypes with no skeleton. In addition, manganese interfered with calcium uptake, perturbed extracellular signal-regulated kinase (ERK) signaling, affected the expression of skeletogenic genes, and caused an increase of the hsc70 and hsc60 protein levels. Here, we extended our studies focusing on the temporal activation of the p38 mitogen-activated protein kinase (p38 MAPK) and the proteolytic activity of metalloprot…

Centrioles Shape ERK Signaling Outcomes to Support Lung Branching

2021

Centrioles comprise the heart of centrosomes, where they organize microtubules. To study the function of centrioles in development, we genetically disrupted centrioles throughout the mouse endoderm. Surprisingly, removing centrioles from endoderm did not disrupt intestinal growth or development. In contrast, in the lung, loss of centrioles blocked branching. In lung, loss of centrioles led to apoptosis specifically of SOX2-expressing airway epithelial cells. Loss of centrioles also activated p53. Deleting p53 in mice with acentriolar endoderm rescued SOX2+ cell survival, lung branching and viability. To investigate why endoderm-wide p53 activation specifically disrupted SOX2+ cell survival,…

MOTIVI E MOTIVAZIONE, FORMA E FORMALISMO: MINIMUM MOTIVO DEL PROVVEDIMENTO E MINIMUM COGNITORIO DEL GIUDIZIO AMMINISTRATIVO DI LEGITTIMITÀ. (NOTA A C…

2010

Characterization of three different clusters of 18S-26S ribosomal DNA genes in the sea urchin P. lividus: Genetic and epigenetic regulation synchrono…

2015

We previously reported the characterization 5S ribosomal DNA (rDNA) clusters in the common sea urchin Paracentrotus lividus and demonstrated the presence of DNA methylation-dependent silencing of embryo specific 5S rDNA cluster in adult tissue. In this work, we show genetic and epigenetic characterization of 18S-26S rDNA clusters in this specie. The results indicate the presence of three different 18S-26S rDNA clusters with different Non-Transcribed Spacer (NTS) regions that have different chromosomal localizations. Moreover, we show that the two largest clusters are hyper-methylated in the promoter-containing NTS regions in adult tissues, as in the 5S rDNA. These findings demonstrate an an…

Statistical power of disease cluster and clustering tests for rare diseases: A simulation study of point sources

2012

Abstract Two recent epidemiological studies on clustering of childhood leukemia showed different results on the statistical power of disease cluster and clustering tests, possibly an effect of spatial data aggregation. Eight different leukemia cluster scenarios were simulated using individual addresses of all 1,009,332 children living in Denmark in 2006. For each scenario, a number of point sources were defined with an increased risk ratio at centroid, decreasing linearly to 1.0 at the edge; aggregation levels were administrative units of Danish municipalities and squares of 5, 12.5 and 25 km 2 . Six statistical methods were compared. Generally, statistical power decreased with increasing s…

Identification and characterization of PlAlix, the Alix homologue from the Mediterranean sea urchin Paracentrotus lividus.

2013

The sea urchin provides a relatively simple and tractable system for analyzing the early stages of embryo development. Here, we use the sea urchin species, Paracentrotus lividus, to investigate the role of Alix in key stages of embryogenesis, namely the egg fertilization and the first cleavage division. Alix is a multifunctional protein involved in different cellular processes including endocytic membrane trafficking, filamentous (F)-actin remodeling, and cytokinesis. Alix homologues have been identified in different metazoans; in these organisms, Alix is involved in oogenesis and in determination/differentiation events during embryo development. Herein, we describe the identification of th…

Aberrant arrested in maturation neuromuscular junctions in centronuclear myopathy

1994

Unusual ultrastructural changes of the nerve terminals have been found in an infant born with severe, fatal XLR form of centronuclear myopathy. Aberrant neuromuscular junctions in myotubes decorated by N-CAM were observed. The junction changes were manifested by simplification of postsynaptic membrane and paucity of secondary synaptic clefts. These resembles fetal neuromuscular junctions. The findings suggest that the expression of N-CAM by arrested myotubes may be promoted by abnormal nerve-muscle cell interactions, induced by motor endplate immaturity.

Meiosis in translocation heterozygotes in the mosquito Culex pipiens.

1971

Adult Culex pipiens males irradiated with both X-rays and neutrons were crossed to untreated females and F1-egg rafts were checked for dominant lethality. F1-progenies were outcrossed with normal individuals in order to obtain lines with inherited semisterility. From a total of 120 lines that showed a certain amount of sterility 12 lines were studied cytologically. 10 lines showed reciprocal chromosome exchanges.—At late pachytene and diplotene cross configurations with large asynaptic regions at the center of the cross are obligatory. Bivalents, chains of three, chains of four, and ring configurations are present at metaphase and anaphase I. The different frequencies of the occurrence of s…

The Genome of the Sea Urchin Strongylocentrotus purpuratus

2006

We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus , a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes.

The oral-facial-digital syndrome gene C2CD3 encodes a positive regulator of centriole elongation

2014

Centrioles are microtubule-based, barrel-shaped structures that initiate the assembly of centrosomes and cilia(1,2). How centriole length is precisely set remains elusive. The microcephaly protein CPAP (also known as MCPH6) promotes procentriole growth(3-5), whereas the oral-facial-digital (OFD) syndrome protein OFD1 represses centriole elongation(6,7). Here we uncover a new subtype of OFD with severe microcephaly and cerebral malformations and identify distinct mutations in two affected families in the evolutionarily conserved C2CD3 gene. Concordant with the clinical overlap, C2CD3 colocalizes with OFD1 at the distal end of centrioles, and C2CD3 physically associates with OFD1. However, wh…