Clonal Diversity in Differently-Aged Populations of the Pseudo-Annual Clonal Plant Circaea lutetiana L.

Plant Biology ◽  
2000 ◽  
Vol 2 (6) ◽  
pp. 646-652 ◽  
Author(s):  
R. Verburg ◽  
J. Maas ◽  
H. J. During
Keyword(s):  
Clonal Diversity ◽  
Clonal Plant

An allozyme study of sexual and vegetative regeneration in Hieracium pilosella

2007 ◽  
Vol 85 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Hans Henrik Bruun ◽  
J.F. Scheepens ◽  
Torbjörn Tyler
Keyword(s):  
Vegetative Reproduction ◽  
Clonal Diversity ◽  
Clonal Plant ◽  
Field Studies ◽  
Relative Importance ◽  
Biotic And Abiotic Stress ◽  
Hieracium Pilosella ◽  
Vegetative Regeneration ◽  
Mesic Site ◽  
Allozyme Study

Allozyme markers were used to fingerprint clones of the grassland plant Hieracium pilosella L. and, by inference, to estimate the relative importance of sexual and vegetative reproduction in a population. Field studies in populations of clonal plant species have often reported negligible or absent recruitment from seed. In contrast, studies of genetic markers have found substantial clonal diversity in populations, suggesting recruitment of new genets into established populations. Our results showed that H. pilosella regenerates from seed both within and between dense clonal patches. Two sites differing in environmental conditions were sampled to investigate how the balance between seed-derived and stolon-derived recruitment changes with biotic and abiotic stress. In a relatively drought-prone site on a south-facing slope, the balance was shifted towards recruitment from seed, compared with a mesic site in which vegetative regeneration was more important.

Variation in clonal structure in an eelgrass (Zostera marina) meadow on the Pacific coast of Canada

1992 ◽  
Vol 70 (3) ◽  
pp. 653-657 ◽  
Author(s):  
Paul G. Harrison ◽  
Cynthia Durance
Keyword(s):  
Zostera Marina ◽  
Clonal Diversity ◽  
Clonal Plant ◽  
Shoot Density ◽  
Banding Patterns ◽  
Original Population ◽  
Drainage Patterns ◽  
The Pacific ◽  
Microgeographic Variation ◽  
A Site

The seagrass Zostera marina L. was studied in southwestern British Columbia at a site where habitat quality has been altered by construction of a port. Morphology, shoot density, and electrophoretic banding patterns for eight enzyme systems were compared in plants from locations that represented the center of the original population (main), a marginal habitat colonized by seedlings, a remnant isolated by changes in drainage patterns, and the subtidal edge of the main bed (deep). Compared with the original population, both the colony and remnant populations had lower shoot densities and shorter shoots. The mean number of banding patterns was lower at the colony and deep locations than at the main location. Clonal diversity was lowest at the main and deep locations. As expected, the colony population shared no clones with the original population. The absence of shared clones in the remnant and original populations suggests that sexual reproduction and seedling establishment are more important in the dynamics of perennial eelgrass populations than is generally believed. Electrophoretically the plants at the seaward margin of the site were the most distinct and uniform; their relation to the other plants is unknown. Key words: clonal plant, electrophoresis, microgeographic variation, population genetic structure, Zostera marina.

Vegetative Propagation of Woody Ornamentals Through Forcing of Epicormic Shoots

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 503c-503
Author(s):  
Paul H. Henry ◽  
John E. Preece
Keyword(s):  
Plant Material ◽  
Woody Plant ◽  
Clonal Plant ◽  
Light Regime ◽  
Moisture Regime ◽  
Stem Cuttings ◽  
Shrub Species ◽  
Woody Ornamentals ◽  
Ornamental Tree ◽  
Environmental Light

A propagation method is being developed that allows softwood shoots to be generated from stem sections of dormant woody plant species. These shoots, forced in the greenhouse during the winter, are subsequently collected and processed as softwood stem cuttings to produce clonal plant material. Many species in the nursery industry can only be propagated using softwood cuttings, and this technique allows propagation of these species to be initiated several months earlier than what is typically possible. Current studies involve expanded screening of ornamental tree and shrub species to determine if commercial production using this technique is feasible. Results demonstrate that many species may be propagated using this method, but that some species are more prolific than others with respect to number of softwood shoots produced. Additional studies are currently in progress to determine the environmental (light regime, moisture regime) and cultural (type of media) conditions that are optimal when producing clonal plant material via this technique.

Clonal Diversity of Ig and T-Cell–Receptor Gene Rearrangements Identifies a Subset of Childhood B-Precursor Acute Lymphoblastic Leukemia With Increased Risk of Relapse

Blood ◽  
1998 ◽  
Vol 92 (3) ◽  
pp. 952-958 ◽  
Author(s):  
Elaine Green ◽  
Carmel M. McConville ◽  
Judith E. Powell ◽  
Jillian R. Mann ◽  
Philip J. Darbyshire ◽  
...  
Keyword(s):  
Acute Lymphoblastic Leukemia ◽  
T Cell ◽  
T Cell Receptor ◽  
Lymphoblastic Leukemia ◽  
Clonal Diversity ◽  
Cell Receptor ◽  
Prognostic Indicators ◽  
Gene Rearrangements ◽  
Risk Patients ◽  
Standard Risk

Abstract Current prognostic indicators such as age, sex, and white blood cell count (WBC) fail to identify all children with more aggressive forms of B-precursor acute lymphoblastic leukemia (ALL), and a proportion of patients without poor prognostic indicators still relapse. Results obtained from an analysis of 65 pediatic B-precursor ALL patients indicated that subclone formation leading to clonal diversity, as detected by Ig and T-cell receptor (TCR) gene rearrangements, may represent a very useful prognostic indicator, independent of age, sex, and WBC. Disease-free survival was significantly shorter in those patients showing clonal diversity at presentation. Furthermore, clonal diversity was detected not only in the majority of high-risk patients who relapsed but was also associated with a high probability of relapse in standard-risk patients. Sixty-five percent (13/20) of standard-risk patients who also showed clonal diversity subsequently relapsed, whereas the percentage of relapses among standard-risk patients without clonal diversity was much lower at 19% (7/36). Continued clonal evolution during disease progression is an important feature of aggressive B-precursor ALL. All 5 patients with clonal diversity who were followed up in our study showed a change in the pattern of clonality between presentation and relapse. This implies an important role for clonal diversity as a mechanism of disease progression through the process of clonal variation and clonal selection. © 1998 by The American Society of Hematology.

scholarly journals Clinical and microbiological characteristics of nosocomial, healthcare-associated, and community-acquired Klebsiella pneumoniae infections in Guangzhou, China

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Tingting Le ◽  
Ling Wang ◽  
Chaoying Zeng ◽  
Leiwen Fu ◽  
Zhihua Liu ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Klebsiella Pneumoniae ◽  
Bacterial Resistance ◽  
Empirical Therapy ◽  
Clonal Diversity ◽  
Extended Spectrum Beta Lactamase ◽  
Microbiological Characteristics ◽  
Carbapenemase Gene ◽  
Cross Transmission ◽  
Healthcare Associated

Abstract Background Klebsiella pneumoniae (K. pneumoniae) is a common pathogen associated with hospital and community-onset infections. This study aimed to compare the clinical and microbiological characteristics of nosocomial, healthcare-associated (HCA), and community-acquired (CA) K. pneumoniae infections. Methods Clinical data were extracted from electronic medical records and analyzed retrospectively. Antimicrobial susceptibility and extended-spectrum beta-lactamase (ESBL) production were determined for all identified strains. Carbapenemase and ESBL genes were amplified by PCR. Genotyping of carbapenem-resistant K. pneumoniae (CRKP) and ESBL-producing strains was performed by pulsed-field gel electrophoresis (PFGE). Results Of 379 K. pneumoniae infections, 98 (25.9%) were nosocomial, 195 (51.5%) were healthcare-associated, and 86 (22.6%) were community-acquired. Hematological malignancy (OR = 4.467), and hypertension (OR = 2.08) and cerebral vascular disease (OR = 2.486) were associated with nosocomial and HCA infections respectively, when compared to CA infections. Overall, the incidence of antimicrobial resistance for the majority of agents tested was similar between nosocomial and HCA infections (P > 0.05) and both groups had a higher incidence than CA infections (P < 0.05). Moreover, 95.1% (78/82) of CRKP strains were isolated from the nosocomial and HCA groups. The blaKPC was the most prevalent carbapenemase gene among CRKP strains (80.5%, 66/82). ESBL-producing strains were prevalent among nosocomial (40.8%), HCA (35.9%) and CA groups (24.4%). The blaCTX-M-9-group and blaCTX-M-1-group genes were predominant in nosocomial (65.0%) and CA strains (66.7%), respectively. PFGE results showed ESBL-producing and CRKP strains were genetically diverse. Identical PFGE profiles were observed among HCA and nosocomial strains. Conclusions Nosocomial and HCA K. pneumoniae infections presented similar clinical features and antimicrobial resistance, and both two types of infections were different to CA infections. CRKP and ESBL-producing strains were disseminated mainly in HCA and nosocomial groups, and showed a clonal diversity. The cross transmission of CRKP was existed among HCA and nosocomial patients. This finding suggests that similar empirical therapy should be considered for patients with nosocomial and HCA K. pneumoniae infections and bacterial resistance surveillance of these infections is necessary.

scholarly journals In Silico Drug Prescription for Targeting Cancer Patient Heterogeneity and Prediction of Clinical Outcome

Cancers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1361
Author(s):  
Elena Piñeiro-Yáñez ◽  
María José Jiménez-Santos ◽  
Gonzalo Gómez-López ◽  
Fátima Al-Shahrour
Keyword(s):  
Cancer Patients ◽  
In Silico ◽  
Tumour Progression ◽  
Drug Prescription ◽  
A Priori ◽  
Growth Factor Receptor ◽  
Clonal Diversity ◽  
Molecular Alterations ◽  
Patient Heterogeneity ◽  
Epidermal Growth

In silico drug prescription tools for precision cancer medicine can match molecular alterations with tailored candidate treatments. These methodologies require large and well-annotated datasets to systematically evaluate their performance, but this is currently constrained by the lack of complete patient clinicopathological data. Moreover, in silico drug prescription performance could be improved by integrating additional tumour information layers like intra-tumour heterogeneity (ITH) which has been related to drug response and tumour progression. PanDrugs is an in silico drug prescription method which prioritizes anticancer drugs combining both biological and clinical evidence. We have systematically evaluated PanDrugs in the Genomic Data Commons repository (GDC). Our results showed that PanDrugs is able to establish an a priori stratification of cancer patients treated with Epidermal Growth Factor Receptor (EGFR) inhibitors. Patients labelled as responders according to PanDrugs predictions showed a significantly increased overall survival (OS) compared to non-responders. PanDrugs was also able to suggest alternative tailored treatments for non-responder patients. Additionally, PanDrugs usefulness was assessed considering spatial and temporal ITH in cancer patients and showed that ITH can be approached therapeutically proposing drugs or combinations potentially capable of targeting the clonal diversity. In summary, this study is a proof of concept where PanDrugs predictions have been correlated to OS and can be useful to manage ITH in patients while increasing therapeutic options and demonstrating its clinical utility.

scholarly journals Molecular investigation of an outbreak associated with total parenteral nutrition contaminated with NDM-producing Leclercia adecarboxylata

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Elvira Garza-González ◽  
Paola Bocanegra-Ibarias ◽  
Eduardo Rodríguez-Noriega ◽  
Esteban González-Díaz ◽  
Jesús Silva-Sanchez ◽  
...  
Keyword(s):  
Comparative Genomics ◽  
Carbapenem Resistance ◽  
Clonal Diversity ◽  
Molecular Characteristics ◽  
Molecular Evidence ◽  
Carbapenem Resistant ◽  
Parental Nutrition ◽  
Genes Encoding ◽  
Main Lineage ◽  
Encoding Genes

Abstract Background This study aimed to determine the epidemiological, microbiological, and molecular characteristics of an outbreak of carbapenem-resistant Leclercia adecarboxylata in three hospitals associated with the unintended use of contaminated total parental nutrition (TPN). Methods For 10 days, 25 patients who received intravenous TPN from the same batch of a formula developed sepsis and had blood cultures positive for L. adecarboxylata. Antimicrobial susceptibility and carbapenemase production were performed in 31 isolates, including one from an unopened bottle of TPN. Carbapenemase-encoding genes, extended-spectrum β-lactamase–encoding genes were screened by PCR, and plasmid profiles were determined. Horizontal transfer of carbapenem resistance was performed by solid mating. Clonal diversity was performed by pulsed-field gel electrophoresis. The resistome was explored by whole-genome sequencing on two selected strains, and comparative genomics was performed using Roary. Results All 31 isolates were resistant to aztreonam, cephalosporins, carbapenems, trimethoprim/sulfamethoxazole, and susceptible to gentamicin, tetracycline, and colistin. Lower susceptibility to levofloxacin (51.6%) and ciprofloxacin (22.6%) was observed. All the isolates were carbapenemase producers and positive for blaNDM-1, blaTEM-1B, and blaSHV-12 genes. One main lineage was detected (clone A, 83.9%; A1, 12.9%; A2, 3.2%). The blaNDM-1 gene is embedded in a Tn125-like element. Genome analysis showed genes encoding resistance for aminoglycosides, quinolones, trimethoprim, colistin, phenicols, and sulphonamides and the presence of IncFII (Yp), IncHI2, and IncHI2A incompatibility groups. Comparative genomics showed a major phylogenetic relationship among L. adecarboxylata I1 and USDA-ARS-USMARC-60222 genomes, followed by our two selected strains. Conclusion We present epidemiological, microbiological, and molecular evidence of an outbreak of carbapenem-resistant L. adecarboxylata in three hospitals in western Mexico associated with the use of contaminated TPN.

Exploitation of environmental Hetergeneity by Spatial Division of Labor in a Clonal Plant

1996 ◽  
Vol 10 (3) ◽  
pp. 328 ◽  
Author(s):  
J. F. Stueffer ◽  
H. De Kroon ◽  
H. J. During
Keyword(s):  
Division Of Labor ◽  
Clonal Plant
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