1,720,985 research outputs found
Smooth muscle-specific SM22 protein is expressed in adventitial cells of ballon-injured rabbit carotid.
No full textFull-length sequence and expression analysis of Toll-like receptor 9 in the gilthead seabream (Sparus aurata L.)
No full textToll-Like Receptors (TLRs) have recently emerged as key sensors of invading microbes, acting through recognition of pathogen-associated molecular patterns. It has been demonstrated that TLR9 is involved in the recognition of unmethylated CpG motifs in mice, humans, and pigs. We report here the full-length sequence of TLR9 cDNA in the gilthead sea bream (Sparus aurata L.). The predicted protein (1063 amino acids) was similar to mammalian TLR9s, showing 21 leucine-rich repeats in the extracellular region and a typical Toll/IL-1R (TIR) domain in the intracellular region. Comparative analysis of TLR9 sequences indicated that critical residues for ligand-binding are conserved across vertebrate lineages, although evidence of functional divergence was observed. Analysis of the genomic structure of sea bream TLR9 gene revealed the presence of two intervening sequences. Retention of the second intron produced an alternatively spliced mRNA (TLR9B) showing differential expression among tissues or developmental stages compared to the wild-type isoform (TLR9A). RT-PCR analysis indicated a broad expression of TLR9A, especially in immune-related organs (spleen, head-kidney) and mucosal-epithelial barriers (gills, gut, skin). Using quantitative Real-Time RT-PCR, no statistically significant variation was observed for TLR9 mRNAs expression in the spleen of experimentally infected animals compared to healthy controls. Comparing sequence and expression profile of sea bream TLR9 with mammalian TLR9s suggested that the main function of TLR9 might be conserved across vertebrates, although species-specific features are present (modulation of ligand-binding specificity, alternative splicing)
CONTRIBUTION OF ADVENTITIAL FIBROBLASTS TO NEOINTIMA FORMATION AND VASCULAR REMODELING: FROM AN INNOCENT BYSTANDER TO ACTIVE PARTICIPANT
No full textThe adventitial layer surrounding the blood vessels has long been exclusively considered a supporting tissue the main function of which is to provide adequate nourishment to the muscle layers of tunica media. Although functionally interconnected, the adventitial and medial layers are structurally interfaced at the external elastic lamina level, clearly distinguishable at the maturational phase of vascular morphogenesis. Over the last few years the “passive” role that the adventitia seemed to play in experimental and spontaneous vascular pathologies involving proliferation, migration, differentiation, and apoptosis of vascular smooth muscle cells (VSMCs) has been questioned. It has been demonstrated that fibroblasts from the adventitia display an important partnership with the resident medial VSMCs in terms of phenotypic conversion, proliferation, apoptotic, and migratory properties the result of which is neointima formation and vascular remodeling. This article is an attempt at reviewing the major themes and more recent findings dealing with the phenotypic conversion process that leads adventitial “passive” (static) fibroblasts to become “activated” (mobile) myofibroblasts. This event shows some facets in common with vascular morphogenesis, ie, the process of recruitment, incorporation, and phenotypic conversion of cells surrounding the primitive endothelial tube in the definitive vessel wall. We hypothesize that during the response to vascular injuries in the adult, “activation” of adventitial fibroblasts is, at least in part, reminiscent of a developmental program that also invests, although with distinct spatiotemporal features, medial VSMC
Genomic Prediction of Resistance to Pasteurellosis in Gilthead Sea Bream (Sparus aurata) Using 2b-RAD Sequencing
Full text linkGilthead sea bream (Sparus aurata) is a species of paramount importance to the Mediterranean aquaculture industry, with an annual production exceeding 140,000 metric tonnes. Pasteurellosis due to the Gram-negative bacterium Photobacterium damselae subsp. piscicida (Phdp) causes significant mortality, especially during larval and juvenile stages, and poses a serious threat to bream production. Selective breeding for improved resistance to pasteurellosis is a promising avenue for disease control, and the use of genetic markers to predict breeding values can improve the accuracy of selection, and allow accurate calculation of estimated breeding values (EBV) of non-challenged animals. In the current study, a population of 825 sea bream juveniles, originating from a factorial cross between 67 broodfish (32 sires; 35 dams), were challenged by 30 min immersion with 1 × 10(5) CFU virulent Phdp. Mortalities and survivors were recorded and sampled for genotyping by sequencing. The 2b-RAD sequencing approach was used to generate genome-wide SNP genotypes for all samples. A high-density linkage map containing 12,085 SNPs grouped into 24 linkage groups (consistent with the karyotype) was constructed. The heritability of surviving days (censored data) was 0.22 (95% highest density interval: 0.11-0.36) and 0.28 (95% highest density interval: 0.17-0.4) using the pedigree and the genomic relationship matrix respectively. A genome wide association study did not reveal individual SNPs significantly associated with resistance at a genome wide significance level. Genomic prediction approaches were tested to investigate the potential of the SNPs obtained by 2bRAD for estimating breeding values for resistance. The accuracy of the genomic prediction models (r = 0.38 - 0.46) outperformed the traditional BLUP approach based on pedigree records (r = 0.30). Overall results suggest that major quantitative trait loci (QTL) affecting resistance to pasteurellosis were not present in this population, but highlight the effectiveness of 2b-RAD genotyping by sequencing for genomic selection in a mass spawning fish species.</p
High mortality of juvenile gilthead sea bream (Sparus aurata) from photobacteriosis is associated with alternative macrophage activation and anti-inflammatory response: Results of gene expression profiling of early responses in the head kidney
No full textThe halophilic bacterium Photobacterium damselae subsp. piscicida (Phdp) represents a substantial health problem for several fish species in aquaculture. Bacteria that reside free and inside phagocytes cause acute and chronic forms of photobacteriosis. Infections of juveniles rapidly kill up to 90-100% fish. Factors underlying failure of the immune protection against bacteria remain largely unknown. The reported study used a transcriptomic approach to address this issue. juvenile sea breams (0.5 g) were challenged by immersion in salt water containing 2.89 x 10(8) CFU of a virulent Phdp and the head kidney was sampled after 24- and 48-h. Analyses were performed using the second version of a 44 k oligonucleotide DNA microarray that represents 19,734 sea bream unique transcripts and covers diverse immune pathways. Expression changes of selected immune genes were validated with qPCR. Results suggested rapid recognition of the pathogen, as testified by up-regulation of lectins and antibacterial proteins (bactericidal permeability-increasing protein lectins, lysozyme, intracellular and extracellular proteases), chemokines and chemokine receptors. Increased expression of proteins involved in iron and heme metabolism also could be a response against bacteria that are dependent on iron. However, negative regulators of immune/inflammatory response were preponderant among the up-regulated genes. A remarkable finding was the increased expression of IL-10 in concert with up-regulation of arginase I and II and proteins of the polyamine biosynthesis pathway that diverts the arginine flux from the production of reactive nitrogen species. Such expression changes are characteristic for alternatively activated macrophages that do not develop acute inflammatory responses. Immune suppression can be induced by the host to reduce tissue damages or by the pathogen to evade host response. (C) 2013 Elsevier Ltd. All rights reserved
Direct identification of Photobacterium damselae subspecies piscicida by PCR-RFLP analysis.
No full textFish pasteurellosis is an infectious disease that affects several teleost species living in temperate marine waters. The pathogen responsible, Photobacterium damselae subspecies piscicida, shows high genetic similarity with P. damselae subsp. damselae, making subspecies discrimination extremely laborious. Here we report for the first time a PCR-RFLP method for the identification of P. damselae subsp. piscicida without prior isolation in pure culture. Genomic sequence information was obtained through cloning and sequencing of RAPD products. Two P. damselae-specific primer pairs were developed and tested on 17 strains of P. damselae subsp. piscicida, 10 strains of P. damselae subsp. damselae, and 6 closely related control species. High sensitivity was achieved in PCR amplification on serially diluted samples (< 180 fg of pure bacterial DNA or < 10 fg, depending on the amplified fragment). Restriction analysis of PCR products showed a unique digestion profile for all P. damselae subsp. piscicida strains. The same PCR-RFLP method was implemented on total DNA samples extracted from experimentally infected sea bream and sea bass. Positive results were obtained on fish with clear signs of the disease as well as on challenged, but asymptomatic, fish. The method presented here might provide a useful tool for both prevention and rapid diagnosis of fish pasteurellosis
Three new sequences of Ostrea stentina and the evolution of the mitogenome of the Ostreinae clams (Ostreidae, Bivalvia)
Full text linkOysters are a group of bivalves forming the family Ostreidae. The identification of oysters at species level is sometimes difficult. The use of molecular data has drastically improved the reliability of species identification and our understanding of their phylogenetic relationships. Markers obtained from mitochondrial genome have played and continue to play a key role in this process. Complete mitogenomes are still unavailable for many oyster species. We sequenced three complete mitogenomes of the dwarf oyster Ostrea stentina. We performed a comparative and evolutionary mitogenomic study of the new sequences combined with all available ones for the Ostreinae. The mitogenome of O. stentina exhibited the standard gene order of Ostreinae, which is different from those observed in other subfamilies of Ostreidae. The study of these mitogenomic arrangements identified gene blocks that were present in the mitogenome of the last common ancestor of the Ostreidae. The comparative analysis allowed identifying peculiar features of the mitogenomes of Ostreinae as well as of their protein coding genes, tRNAs genes, rRNA genes, and control regions. The genus Ostrea resulted polyphyletic in the mito-phylogenomic analysis. The stems and loops of several tRNAs contained short DNA motifs useful to identify single species/groups of species. Short sequences, playing the role of molecular signatures characterizing a single taxon or a group of species, were identified also in the intergenic spacers. The identification of these taxonomic and phylogenetic markers reinforces the crucial role of mitogenomes in elucidating the evolutionary history of oysters
Genetic variability and population structure analysis of Protostrongylus oryctolagi (Nematoda: Protostrongylidae) in Lepus europaeus from Central and Northern Italy.
Full text linkNematodes are abundant and ubiquitous animals which are poorly known at intraspecific level. This work represents the first attempt to fill the gap on basic knowledge of genetic variability and differentiation in Protostrongylus oryctolagi, a nematode parasite of lagomorphs. 68 cox1 sequences were obtained from brown hares collected in five locations in Northern and Central Italy, highlighting the presence of a high amount of genetic variation inside this species. The eleven haplotypes identified (Haplotype diversity equal to 0.702) were split into two lineages: lineage A (comprising six different haplotypes, A1-A6) and lineage B (B1-B5). The mean intra-lineage amount of genetic variation was 0.3%, whereas the inter-lineage percentage of variation was ten-fold higher (3%). These two lineages were non-randomly distributed in the investigated areas. Lineage A showed a preference for Central Italy (Tuscany) even if it was sporadically found also in northern territories (Emilia-Romagna), while B-haplotypes were present exclusively in Emilia-Romagna. The analysis of molecular variance identified two main barriers to gene flow: (i) a strong major one which separate samples of Central Italy (PIA and GR7) from the northern ones (RE1, RE3 and MO1; ΦST = 0.750, P = 0.00); (ii) a secondary faint barrier which separates Pianosa island from Grosseto (ΦST = 0.133, P = 0.00). Any difference was found among northern samples (ΦST = 0.009, P = 0.00). The observed data may be explained by several factors ranging from the parasite's biology (presence of a narrow host spectrum), the final host's behaviour (small home range), the natural dispersion of the host-parasite dyad occurred in past or the recent passive men-mediated migration. Finally, the presence of unconventional shortened amplicons revealed the presence of NUMTs (nuclear copy of mitochondrial genes) in the P. oryctolagi nuclear genome, suggesting caution when using DNA barcode as unique marker for the identification of species belonging to this genus. "In short, if all the matter in the universe except the nematodes were swept away, our world would still be dimly recognizable". Nathan Augustus Cobb, from "Nematodes and Their Relationships", 1915
An integrated genomic approach for the study of mandibular prognathism in the European seabass (Dicentrarchus labrax)
Full text linkSkeletal anomalies in farmed fish are a relevant issue affecting animal welfare and health and causing significant economic losses. Here, a high-density genetic map of European seabass for QTL mapping of jaw deformity was constructed and a genome-wide association study (GWAS) was carried out on a total of 298 juveniles, 148 of which belonged to four full-sib families. Out of 298 fish, 107 were affected by mandibular prognathism (MP). Three significant QTLs and two candidate SNPs associated with MP were identified. The two GWAS candidate markers were located on ChrX and Chr17, both in close proximity with the peaks of the two most significant QTLs. Notably, the SNP marker on Chr17 was positioned within the Sobp gene coding region, which plays a pivotal role in craniofacial development. The analysis of differentially expressed genes in jaw-deformed animals highlighted the "nervous system development" as a crucial pathway in MP. In particular, Zic2, a key gene for craniofacial morphogenesis in model species, was significantly down-regulated in MP-affected animals. Gene expression data revealed also a significant down-regulation of Sobp in deformed larvae. Our analyses, integrating transcriptomic and GWA methods, provide evidence for putative mechanisms underlying seabass jaw deformity
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