342 research outputs found
Cytological and molecular characterization of three gametoclones of Citrus clementina
Abstract
Background
Three gametoclonal plants of Citrus clementina Hort. ex Tan., cv. Nules, designated ESP,
FRA, and ITA (derived from three labs in Spain, France, and Italy, respectively), were
selected for cytological and molecular characterization in order to elucidate genomic
rearrangements provoked by haploidization. The study included comparisons of their ploidy,
homozygosity, genome integrity, and gene dosage, using chromosome counting, flow
cytometry, SSR marker genotyping, and array-Comparative Genomic Hybridization (arrayCGH).
Results
Chromosome counting and flow cytometry revealed that ESP and FRA were haploid, but ITA
was tri-haploid. Homozygous patterns, represented by a single peak (allele), were observed
among the three plants at almost all SSR loci distributed across the entire diploid donor
genome. Those few loci with extra peaks visualized as output from automated sequencing
runs, generally low or ambiguous, might result from amplicons of paralogous members at the
locus, non-specific sites, or unexpected recombinant alleles. No new alleles were found,
suggesting the genomes remained stable and intact during gametogenesis and regeneration.
The integrity of the haploid genome also was supported by array-CGH studies, in which
genomic profiles were comparable to the diploid control.
Conclusions
The presence of few gene hybridization abnormalities, corroborated by gene dosage
measurements, were hypothetically due to the segregation of hemizygous alleles and minor
genomic rearrangements occurring during the haploidization procedure. In conclusion, these
plants that are valuable genetic and breeding materials contain completely homozygous and
essentially intact genomes
Structural and functional effects of selective chemical modifications of Scapharca inaequivalvis haemoglobins in relation to their unique assembly
Exploring lactic acid bacteria diversity of hop plant by-products to develop a multi-strain starter culture to be used in hop-supplemented sourdough bread
The hop plant is gaining interest in the food, pharmaceutical, and cosmetics industries due to its abundance of secondary metabolites. However, branches and leaves, despite their antioxidant potential, are typically discarded. To valorize these components as functional ingredients they were dried, milled into hop powder (HP), and used to enrich bread. Polyphenol-resistant lactic acid bacteria (LAB) isolated in this study from HP, Leuconostoc pseudomesenteroides and Enterococcus lactis, were selected for their acidification capacity and combined with sourdough LAB to create a multi-strain starter culture for hop bread (HB) production. Three trials were conducted: HB-0 (control bread without HP), HB-2.5 (bread with 2.5 % HP), and HB-5 (bread with 5 % HP). All samples were evaluated for quality traits, phenolic content, antioxidant activity, and profiles of polyphenols and volatile organic compounds (VOCs). HP-supplemented breads showed reduced weight loss, increased firmness, and darker crust and crumb. Bioactive compounds such as xanthohumol, lupulone, and VOCs like beta-myrcene and alpha-humulene were retained. Sensory analysis revealed that HP addition enhanced aroma intensity, color, astringency, and bitterness, with HB-2.5 receiving the highest overall rating. Shelf life tests showed mold appeared on day 11 in HB-0, but was delayed to day 13 in HP breads. Staling, assessed via differential scanning calorimetry, showed increasing melting enthalpy (Delta H) over time in all samples, confirming starch retrogradation, with no significant differences among formulations. This study validates the use of HP as a functional ingredient, enhancing sensory profiles and bioactive compound content. The application of selected LAB and HP supports sustainable practices in the food sector
Direct Observation of Cooperative Protein Structural Dynamics of Homodimeric Hemoglobin from 100 ps to 10 ms with Pump–Probe X-ray Solution Scattering
Proteins serve as molecular machines in performing their biological functions, but the detailed structural transitions are difficult to observe in their native aqueous environments in real time. For example, despite extensive studies, the solution-phase structures of the intermediates along the allosteric pathways for the transitions between the relaxed (R) and tense (T) forms have been elusive. In this work, we employed picosecond X-ray solution scattering and novel structural analysis to track the details of the structural dynamics of wild-type homodimeric hemoglobin (HbI) from the clam Scapharca inaequivalvis and its F97Y mutant over a wide time range from 100 ps to 56.2 ms. From kinetic analysis of the measured time-resolved X-ray solution scattering data, we identified three structurally distinct intermediates (I-1, I-2, and I-3) and their kinetic pathways common for both the wild type and the mutant. The data revealed that the singly liganded and unliganded forms of each intermediate share the same structure, providing direct evidence that the ligand photolysis of only a single subunit induces the same structural change as the complete photolysis of both subunits does. In addition, by applying novel structural analysis to the scattering data, we elucidated the detailed structural changes in the protein, including changes in the heme heme distance, the quaternary rotation angle of subunits, and interfacial water gain/loss. The earliest, R-like I-1 intermediate is generated within 100 ps and transforms to the R-like I-2 intermediate with a time constant of 3.2 +/- 0.2 ns. Subsequently, the late, T-like I-3 intermediate is formed via subunit rotation, a decrease in the heme-heme distance, and substantial gain of interfacial water and exhibits ligation-dependent formation kinetics with time constants of 730 +/- 120 ns for the fully photolyzed form and 5.6 +/- 0.8 mu s for the partially photolyzed form. For the mutant, the overall kinetics are accelerated, and the formation of the T-like I-3 intermediate involves interfacial water loss (instead of water entry) and lacks the contraction of the heme-heme distance, thus underscoring the dramatic effect of the F97Y mutation. The ability to keep track of the detailed movements of the protein in aqueous solution in real time provides new insights into the protein structural dynamics.1149sciescopu
A Histone-Like Protein of Mycobacteria Possesses Ferritin Superfamily Protein-Like Activity and Protects against DNA Damage by Fenton Reaction
Iron is an essential metal for living organisms but its level must be strictly controlled in cells, because ferrous ion induces toxicity by generating highly active reactive oxygen, hydroxyl radicals, through the Fenton reaction. In addition, ferric ion shows low solubility under physiological conditions. To overcome these obstacles living organisms possess Ferritin superfamily proteins that are distributed in all three domains of life: bacteria, archaea, and eukaryotes. These proteins minimize hydroxyl radical formation by ferroxidase activity that converts Fe2+ into Fe3+ and sequesters iron by storing it as a mineral inside a protein cage. In this study, we discovered that mycobacterial DNA-binding protein 1 (MDP1), a histone-like protein, has similar activity to ferritin superfamily proteins. MDP1 prevented the Fenton reaction and protects DNA by the ferroxidase activity. The Km values of the ferroxidase activity by MDP1 of Mycobacterium bovis bacillus Calmette-Guérin (BCG-3007c), Mycobacterium tuberculosis (Rv2986c), and Mycobacterium leprae (ML1683; ML-LBP) were 0.292, 0.252, and 0.129 mM, respectively. Furthermore, one MDP1 molecule directly captured 81.4±19.1 iron atoms, suggesting the role of this protein in iron storage. This study describes for the first time a ferroxidase-iron storage protein outside of the ferritin superfamily proteins and the protective role of this bacterial protein from DNA damage
Impact of gastrointestinal side effects on patients’ reported quality of life trajectories after radiotherapy for prostate cancer: Data from the prospective, observational pros-it CNR study
Radiotherapy (RT) represents an important therapeutic option for the treatment of localized prostate cancer. The aim of the current study is to examine trajectories in patients’ reported quality of life (QoL) aspects related to bowel function and bother, considering data from the PROState cancer monitoring in ITaly from the National Research Council (Pros-IT CNR) study, analyzed with growth mixture models. Data for patients who underwent RT, either associated or not associated with androgen deprivation therapy, were considered. QoL outcomes were assessed over a 2-year period from the diagnosis, using the Italian version of the University of California Los Angeles-Prostate Cancer Index (Italian-UCLA-PCI). Three trajectories were identified for the bowel function; having three or more comorbidities and the use of 3D-CRT technique for RT were associated with the worst trajectory (OR = 3.80, 95% CI 2.04–7.08; OR = 2.17, 95% CI 1.22–3.87, respectively). Two trajectories were identified for the bowel bother scores; diabetes and the non-Image guided RT method were associated with being in the worst bowel bother trajectory group (OR = 1.69, 95% CI 1.06–2.67; OR = 2.57, 95% CI 1.70–3.86, respectively). The findings from this study suggest that the absence of comorbidities and the use of intensity modulated RT techniques with image guidance are related with a better tolerance to RT in terms of bowel side effects
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