Molecular modeling of S-RNases involved in almond self-incompatibility

Gametophytic self-incompatibility (GSI) is a mechanism in flowering plants, to prevent inbreeding and promote outcrossing. GSI is under the control of a specific locus, known as the S-locus, which contains at least two genes, the RNase and the SFB. Active S-RNases in the style are essential for rejection of haploid pollen, when the pollen S-allele matches one of two S-alleles of the diploid pistil. However, the nature of their mutual interactions at genetic and biochemical levels remain unclear. Thus, detailed understanding of the protein structure involved in GSI may help in discovering how the proteins involved in GSI may function and how they fulfill their biological roles. To this end, 3D models of the SC (Sf) and two SI (S8 and S23) S-RNases of almond were constructed, using comparative modeling tools. The modeled structures consisted of mixed α and β folds, with six helices and six β-strands. However, the self-compatible (Sf) RNase contained an additional extended loop between the conserved domains RC4 and C5, which may be involved in the manifestation of self-compatibility in almond

Pollen Tube Growth and Self-Compatibility in Almond

Although pollen tube growth has been an important criterion for self-compatibility evaluation in almond, there is not a clear-cut separation between positive and negative growth of pollen tubes in the different genotypes. The examination of pollen tube growth after selfing almond seedlings has allowed establishing different levels of compatibility, but not a clear-cut separation between self-compatible (SC) and self-incompatible (SI) genotypes, related to the presence of pseudo-self-compatibility in almond. Consequently, a relationship between pollen tube growth and self-compatibility in almond may be established for evaluating the seedlings in breeding programs

Mapping quantitative trait loci for kernel composition in almond

<p>Abstract</p> <p>Background</p> <p>Almond breeding is increasingly taking into account kernel quality as a breeding objective. Information on the parameters to be considered in evaluating almond quality, such as protein and oil content, as well as oleic acid and tocopherol concentration, has been recently compiled. The genetic control of these traits has not yet been studied in almond, although this information would improve the efficiency of almond breeding programs.</p> <p>Results</p> <p>A map with 56 simple sequence repeat or microsatellite (SSR) markers was constructed for an almond population showing a wide range of variability for the chemical components of the almond kernel. A total of 12 putative quantitative trait loci (QTL) controlling these chemical traits have been detected in this analysis, corresponding to seven genomic regions of the eight almond linkage groups (LG). Some QTL were clustered in the same region or shared the same molecular markers, according to the correlations already found between the chemical traits. The logarithm of the odds (LOD) values for any given trait ranged from 2.12 to 4.87, explaining from 11.0 to 33.1 % of the phenotypic variance of the trait.</p> <p>Conclusions</p> <p>The results produced in the study offer the opportunity to include the new genetic information in almond breeding programs. Increases in the positive traits of kernel quality may be looked for simultaneously whenever they are genetically independent, even if they are negatively correlated. We have provided the first genetic framework for the chemical components of the almond kernel, with twelve QTL in agreement with the large number of genes controlling their metabolism.</p

Identification of quantitative trait loci associated with self-compatibility in a Prunus species

Self-compatibility in Rosaceous fruit species is based on a single-locus qualitative trait. However, the evidence observed in different species has indicated the presence of modifier genes outside the S locus affecting the expression of self-compatibility/self-incompatibility. The study of a progeny obtained from the cross of the almond genotypes ‘Vivot’× ‘Blanquerna’ has allowed the construction of a genetic map based on microsatellite markers and the identification for the first time in the Rosaceae family of two additional loci located outside the S locus and affecting the expression of self-compatibility/self-incompatibility. A quantitative trait locus (QTL) was located relatively close to the S locus, on linkage group 6 (G6), whereas the second one was located on G8. These QTLs appear to be involved in conferring self-compatibility to genotypes not possessing the S f allele. These results are consistent with almond being a self-incompatible species with a genetic background of pseudo-self-compatibility controlled by modifier genes. The effect of the S f allele and the two QTLs may contribute to explain the wide range of fruit sets observed when self-pollinating different almond genotypes.This research was funded by the grants CICYT AGL2007-65853-C02-02 and the Research Group A12 of Aragón. À. Fernández i Martí acknowledges a scholarship co-funded by the Spanish ‘Ministerio de Educación y Ciencia’ and the European Social Fund (FSE), under projects AGL 2004-06674-C02-01 and BES-2006-12621. The IRTA group is member of the Consolider-Imagenio 2010 project funded by the Spanish Ministry of Science and Innovation.Peer reviewe

Antineutrophil cytoplasmic antibodies in sera from colectomised ulcerative colitis patients and its relation to the presence of pouchitis.

BACKGROUND: Few studies have evaluated the influence of colectomy on antineutrophil cytoplasmic antibody (ANCA) positivity in ulcerative colitis (UC). In small series of patients it has been suggested that ANCA positivity in UC might be predictive for development of pouchitis after colectomy. AIMS: To assess the prevalence of ANCA in UC patients treated by colectomy and a Brooke's ileostomy (UC-BI) or ileal pouch anal anastomosis (UC-IPAA), and the relation between the presence of ANCA, the type of surgery, and the presence of pouchitis. SUBJECTS: 63 UC patients treated by colectomy (32 with UC-BI and 31 with UC-IPAA), 54 UC, and 24 controls. METHODS: Samples were obtained at least two years after colectomy. ANCA were detected by indirect immunofluorescent assay. RESULTS: There were no differences between patients with (36.3%) or without pouchitis (35.0%) and between patients with UC (55%), UC-BI (40.6%), and UC-IPAA (35.4%). However, ANCA prevalence significantly decreases in the whole group of operated patients (38.0%) compared with non-operated UC (p = 0.044). CONCLUSIONS: The prevalence of ANCA in operated patients was significantly lower than in non-operated UC, suggesting that it might be related either to the presence of inflamed or diseased tissue. ANCA persistence is not related to the surgical procedure and it should not be used as a marker for predicting the development of pouchitis

Els Casots (Subirats, Catalonia), a key site for the Miocene vertebrate record of Southwestern Europe

discovered in 1989 and excavated briefly during the 1990s, resulting in the recovery of thousands of remains and the erection of several new mammal species. Excavations resumed in 2018 and continue to date. Here we provide updated results regarding the age, stratigraphy, biota and palaeoenvironment of the site. The age of the site is well constrained to ~15.9 Ma thanks to recent bio- and magnetostratigraphic data, thus coinciding with the onset of the Miocene Climatic Optimum (MCO). The stratigraphic succession at the site area indicates lacustrine to palustrine environments with cyclically oscillating water level. There are several fossiliferous layers that have yielded a vertebrate fauna comprising up to 74 different vertebrate species including amphibians, reptiles, birds and mostly mammals. The finding of several articulated partial skeletons indicate that the site records an autochthonous to parautochthonous assemblage. The abundance and completeness of the vertebrate remains together with a well-constrained age and detailed stratigraphic and palaeoenvironmental data, make els Casots a key site for understanding wetland ecosystems in southern Europe during the MCO