Search results for "Clonal Selection"
showing 8 items of 8 documents
Genetic diversity and clonal variation within the main Sicilian olive cultivars based on morphological traits and microsatellite markers
2014
The richness of Olea europaea (L.) genetic resources in Sicily is well documented. In the last 30 years, mostof the local cultivars, landraces and ecotypes have been gathered together in a large ex-situ collection,containing more than 300 genotypes. In this study, 45 putative clones of the main Sicilian olive cultivarswere characterized morphologically using microsatellite markers to unambiguously identify possiblesuperior genotypes. The microsatellites employed were polymorphic (observed heterozygosity = 0.71;polymorphic information content = 0.59), discriminated 52% of the genotypes and enabled the detectionof intra-cultivar polymorphism, derived from both somatic mutations, indicating th…
Thymus-derived regulatory T cells are positively selected on natural self-antigen through cognate interactions of high functional avidity
2016
Regulatory T (Treg) cells expressing Foxp3 transcripton factor are essential for immune homeostasis. They arise in the thymus as a separate lineage from conventional CD4+Foxp3- T (Tconv) cells. Here, we show that the thymic development of Treg cells depends on the expression of their endogenous cognate self-antigen. The formation of these cells was impaired in mice lacking this self-antigen, while Tconv cell development was not negatively affected. Thymus-derived Treg cells were selected by self-antigens in a specific manner, while autoreactive Tconv cells were produced through degenerate recognition of distinct antigens. These distinct modes of development were associated with the expressi…
Intra-cultivar Diversity in sicilian and calabrian olive (olea europaea L.) Cultivars Depicted by Morphological Traits and SSR Markers
2012
In this study, SSR analysis was performed on a large number of putative clones of the main olive cultivars from two Italian regions, Sicily and Calabria, in order to study the genetic relatedness, and to detect any degree of genetic diversity, which can be used to unambiguously identify possible superior clones. These putative clones have been collected and observed in the last ten years, following an extensive investigation carried out in traditional olive growing areas, thanks to the reports of farmers, millers, technician, growers and nurseries. The set of microsatellite (SSR) markers used allowed the detection of the genetic diversity, resulting from somatic mutation, indicating the pre…
INTRA-CULTIVAR DIVERSITY IN SOUTHERN ITALY OLIVE CULTIVARS DEPICTED BY MORPHOLOGICAL TRAITS AND SSR MARKERS
2014
In this study, SSR analysis was performed on a large number of putative clones of the main olive cultivars from two Italian regions, Sicily and Calabria, in order to study the genetic relatedness, and to detect any degree of genetic diversity, which can be used to unambiguously identify possible superior clones. These putative clones have been collected and observed in the last ten years, following an extensive investigation carried out in traditional olive growing areas, thanks to the reports of farmers, millers, technician, growers and nurseries. The set of microsatellite (SSR) markers used allowed the detection of the genetic diversity, resulting from somatic mutation, indicating the pre…
Eomes broadens the scope of CD8 T-cell memory by inhibiting apoptosis in cells of low affinity.
2020
The memory CD8 T-cell pool must select for clones that bind immunodominant epitopes with high affinity to efficiently counter reinfection. At the same time, it must retain a level of clonal diversity to allow recognition of pathogens with mutated epitopes. How the level of diversity within the memory pool is controlled is unclear, especially in the context of a selective drive for antigen affinity. We find that preservation of clones that bind the activating antigen with low affinity depends on expression of the transcription factor Eomes in the first days after antigen encounter. Eomes is induced at low activating signal strength and directly drives transcription of the prosurvival protein…
Genetic Improvement of Sweet Chestnut in Sicily (Castanea sativa Mill.) by the Selection of Superior Autochthonous Genotypes
2010
In Sicily, the chestnut (Castanea sativa Mill.) grows in limited areas of the South eastern Mt. Etna volcano and of the Northern Mountains, namely Madonie and Nebrodi. In the Island, chestnut can be considered as a neglected species, because of the modest importance recognized to it for horticultural and forestry exploitation. Recently, the Sicilian regional government founded the 'Horticultural Forestry' project to promote the cultivation of chestnut as possible fruit tree for local city farmer markets, where typical products are usually sold. The project was developed in five steps, carried out during three years by the Dipartimento di Colture Arboree of Palermo University: identification…
Ci8 short, a novel LPS-induced peptide from the ascidian Ciona intestinalis,modulates responses of the human immune system
2017
The selective modulation of immunity is an emerging concept driven by the vast advances in our understanding of this crucial host defense system. Invertebrates have raised researchers’ interest as potential sources of new bioactive molecules owing to their antibacterial, anticancer and immunomodulatory activities. A LipoPolySaccharide (LPS) challenge in the ascidian Ciona intestinalis generates the transcript, Ci8 short, with cisregulatory elements in the 3′ UTR region that are essential for shaping innate immune responses. The derived amino acidic sequence in silico analysis showed specific binding to human Major Histocompatibility Complex (MHC) Class I and Class II alleles. The role of Ci…
Morphological and molecular variability within the fig cultivar 'Dottato' in the Italian protected designation origin area "fichi di Cosenza"
2017
The morphological and molecular diversity among fig accessions of 'Dottato', found in the PDO "Fichi di Cosenza" area was studied by evaluating 24 morphological traits and by genotyping with 18 microsatellite markers. The microsatellite allelic profiles among the putative clones of 'Dottato' indicated a moderate genetic variability, discriminating unambiguously most of the accessions. Only two groups of identity were found. The average expected and observed heterozygosity were 0.43 and 0.62, respectively. The mean polymorphic information content (PIC) was 0.4, varying from 0.08 (LMFC26) to 0.067 (FCUP 38-6). The morphological clustering allowed the distinction of all genotypes. Some genotyp…