The Genus Is at Least as Well Supported as , , and . Comment on Moreyra et al. African Mountain Thistles: Three New Genera in the - Group. 2023, , 3083.

Moreyra and co-authors, in their recent paper published in , presented a desperately needed Hyb-Seq phylogeny of the genus . Through their findings, they provided a critical assessment of an earlier proposal of ours to separate sect. and into the genera and , respectively.

Centromere drive may propel the evolution of chromosome and genome size in plants.

Background: Genome size is influenced by natural selection and genetic drift acting on variations from polyploidy and repetitive DNA sequences. We hypothesized that centromere drive, where centromeres compete for inclusion in the functional gamete during meiosis, may also affect genome and chromosome size. This competition occurs in asymmetric meiosis, where only one of the four meiotic products becomes a gamete.

Genome size is positively correlated with extinction risk in herbaceous angiosperms.

Angiosperms with large genomes experience nuclear-, cellular-, and organism-level constraints that may limit their phenotypic plasticity and ecological niche, which could increase their risk of extinction. Therefore, we test the hypotheses that large-genomed species are more likely to be threatened with extinction than those with small genomes, and that the effect of genome size varies across three selected covariates: life form, endemism, and climatic zone. We collated genome size and extinction risk information for a representative sample of angiosperms comprising 3250 species, which we analyzed alongside life form, endemism, and climatic zone variables using a phylogenetic framework.

The smallest angiosperm genomes may be the price for effective traps of bladderworts.

Background: Species of the carnivorous family Lentibulariaceae exhibit the smallest genomes in flowering plants. We explored the hypothesis that their minute genomes result from the unique mitochondrial cytochrome c oxidase (COX) mutation. The mutation may boost mitochondrial efficiency, which is especially useful for suction-bladder traps of Utricularia, but also increase DNA-damaging reactive oxygen species, leading to genome shrinkage through deletion-biased DNA repair.

Genome size variation in Cape schoenoid sedges (Schoeneae) and its ecophysiological consequences.

Premise: Increases in genome size in plants-often associated with larger, low-density stomata and greater water-use efficiency (WUE)-could affect plant ecophysiological and hydraulic function. Variation in plant genome size is often due to polyploidy, having occurred repeatedly in the austral sedge genus Schoenus in the Cape Floristic Region (CFR), while species in the other major schoenoid genus in the region, Tetraria, have smaller genomes. Comparing these genera is useful as they co-occur at the landscape level, under broadly similar bioclimatic conditions.

The Effect of Physical Restraint on a Violent Patient in the Prone Position on the Quality of Breathing: A Pilot Simulation Study.

Objectives: Physical restraint in the prone position is still utilized in healthcare facilities to immobilize violent patients. It is associated with the sudden death of violent patients. The aim of this study is to objectify the impact of physical restraint in the prone position on spirometric and ventilatory parameters.

The global distribution of angiosperm genome size is shaped by climate.

Angiosperms, which inhabit diverse environments across all continents, exhibit significant variation in genome sizes, making them an excellent model system for examining hypotheses about the global distribution of genome size. These include the previously proposed large genome constraint, mutational hazard, polyploidy-mediated, and climate-mediated hypotheses. We compiled the largest genome size dataset to date, encompassing 16 017 (> 5% of known) angiosperm species, and analyzed genome size distribution using a comprehensive geographic distribution dataset for all angiosperms.

An insight into the functional genomics and species classification of Eudiplozoon nipponicum (Monogenea, Diplozoidae), a haematophagous parasite of the common carp Cyprinus carpio.

Background: Monogenea (Platyhelminthes, Neodermata) are the most species-rich class within the Neodermata superclass of primarily fish parasites. Despite their economic and ecological importance, monogenean research tends to focus on their morphological, phylogenetic, and population characteristics, while comprehensive omics analyses aimed at describing functionally important molecules are few and far between. We present a molecular characterisation of monogenean representative Eudiplozoon nipponicum, an obligate haematophagous parasite infecting the gills of the common carp.

Growth, physiology, and stomatal parameters of plant polyploids grown under ice age, present-day, and future CO concentrations.

Polyploidy plays an important role in plant evolution, but knowledge of its eco-physiological consequences, such as of the putatively enlarged stomata of polyploid plants, remains limited. Enlarged stomata should disadvantage polyploids at low CO concentrations (namely during the Quaternary glacial periods) because larger stomata are viewed as less effective at CO uptake. We observed the growth, physiology, and epidermal cell features of 15 diploids and their polyploid relatives cultivated under glacial, present-day, and potential future atmospheric CO concentrations (200, 400, and 800 ppm respectively).

Chromosome size matters: genome evolution in the cyperid clade.

Background And Aims: While variation in genome size and chromosome numbers and their consequences are often investigated in plants, the biological relevance of variation in chromosome size remains poorly known. Here, we examine genome and mean chromosome size in the cyperid clade (families Cyperaceae, Juncaceae and Thurniaceae), which is the largest vascular plant lineage with predominantly holocentric chromosomes.

Methods: We measured genome size in 436 species of cyperids using flow cytometry, and augment these data with previously published datasets.

Transcriptome and proteome associated analysis of flavonoid metabolism in haploid Ginkgo biloba.

Having different number if genome copies affect transcription and metabolite production of plants. This may be due to different gene transcription and protein expression, but the reasons for this remains poorly known. Here we measured flavonoid content in leaves of three haploid and diploid grafted plants of Ginkgo biloba, a model gymnosperm important economically for its flavonoid content.

Kinetochore size scales with chromosome size in bimodal karyotypes of Agavoideae.

Background And Aims: In eukaryotes, the total kinetochore size (defined as a chromosomal region containing CENH3-positive nucleosomes) per nucleus strongly correlates with genome size, a relationship that has been hypothesized to stem from general intracellular scaling principles. However, if larger chromosomes within a karyotype required larger kinetochores to move properly, it could also be derived from the mechanics of cell division.

Methods: We selected seven species of the plant subfamily Agavoideae whose karyotypes are characterized by the presence of small and very large chromosomes.

Complex patterns of ploidy in a holocentric plant clade (Schoenus, Cyperaceae) in the Cape biodiversity hotspot.

Background And Aims: It is unclear how widespread polyploidy is throughout the largest holocentric plant family - the Cyperaceae. Because of the prevalence of chromosomal fusions and fissions, which affect chromosome number but not genome size, it can be impossible to distinguish if individual plants are polyploids in holocentric lineages based on chromosome count data alone. Furthermore, it is unclear how differences in genome size and ploidy levels relate to environmental correlates within holocentric lineages, such as the Cyperaceae.

Centromere size scales with genome size across Eukaryotes.

Previous studies on grass species suggested that the total centromere size (sum of all centromere sizes in a cell) may be determined by the genome size, possibly because stable scaling is important for proper cell division. However, it is unclear whether this relationship is universal. Here we analyze the total centromere size using the CenH3-immunofluorescence area as a proxy in 130 taxa including plants, animals, fungi, and protists.

Application-based guidelines for best practices in plant flow cytometry.

Flow cytometry (FCM) is currently the most widely-used method to establish nuclear DNA content in plants. Since simple, 1-3-parameter, flow cytometers, which are sufficient for most plant applications, are commercially available at a reasonable price, the number of laboratories equipped with these instruments, and consequently new FCM users, has greatly increased over the last decade. This paper meets an urgent need for comprehensive recommendations for best practices in FCM for different plant science applications.

Holocentric Chromosomes Probably Do Not Prevent Centromere Drive in Cyperaceae.

Centromere drive model describes an evolutionary process initiated by centromeric repeats expansion, which leads to the recruitment of excess kinetochore proteins and consequent preferential segregation of an expanded centromere to the egg during female asymmetric meiosis. In response to these selfish centromeres, the histone protein CenH3, which recruits kinetochore components, adaptively evolves to restore chromosomal parity and counter the detrimental effects of centromere drive. Holocentric chromosomes, whose kinetochores are assembled along entire chromosomes, have been hypothesized to prevent expanded centromeres from acquiring a selective advantage and initiating centromere drive.

Is the evolution of carnivory connected with genome size reduction?

Premise: As repeatedly shown, the remarkable variation in the genome size of angiosperms can be shaped by extrinsic selective pressures, including nutrient availability. Carnivory has evolved independently in 10 angiosperm clades, but all carnivorous plants share a common affinity to nutrient-poor habitats. As such, carnivory and genome reduction could be responses to the same environmental pressure.

Endopolyploidy is a common response to UV-B stress in natural plant populations, but its magnitude may be affected by chromosome type.

Background And Aims: Ultraviolet-B radiation (UV-B) radiation damages the DNA, cells and photosynthetic apparatus of plants. Plants commonly prevent this damage by synthetizing UV-B-protective compounds. Recent laboratory experiments in Arabidopsis and cucumber have indicated that plants can also respond to UV-B stress with endopolyploidy.

Environmental pressures on stomatal size may drive plant genome size evolution: evidence from a natural experiment with Cape geophytes.

Background And Aims: The idea that genome (size) evolution in eukaryotes could be driven by environmental factors is still vigorously debated. In extant plants, genome size correlates positively with stomatal size, leading to the idea that conditions enabling the existence of large stomata in fossil plants also supported growth of their genome size. We test this inductive assumption in drought-adapted, prostrate-leaved Cape (South Africa) geophytes where, compared with their upright-leaved geophytic ancestors, stomata develop in a favourably humid microclimate formed underneath their leaves.

Anaphylaxis in Public Health.

The increasing number of patients with anaphylactic reactions is a modern challenge for healthcare professionals in clinical practice and public health professionals. It remains difficult to determine the prevalence or incidence of anaphylaxis in the population due to the long absence of a consensus definition, the fact that analyses are performed on various population groups and the use of different data collection methodologies. In the United States, anaphylaxis mortality ranges from 0.

Insights into the karyotype and genome evolution of haplogyne spiders indicate a polyploid origin of lineage with holokinetic chromosomes.

Spiders are an ancient and extremely diverse animal order. They show a considerable diversity of genome sizes, karyotypes and sex chromosomes, which makes them promising models to analyse the evolution of these traits. Our study is focused on the evolution of the genome and chromosomes in haplogyne spiders with holokinetic chromosomes.

Pest Arthropods with Holocentric Chromosomes are More Resistant to Sterilizing Ionizing Radiation.

It has been hypothesized that species with holocentric chromosomes have a selective evolutionary advantage for developmental and reproductive success because holocentric chromosomes are less susceptible to chromosome breakage than monocentric chromosomes. We analyzed data on sterilizing doses of ionizing radiation for more than 250 species of arthropods to test whether the minimal dose for reproductive sterilization is higher for species with holocentric chromosomes than for species with monocentric chromosomes. Using linear mixed models that account for phylogeny, we show that holocentric arthropods are more tolerant of sterilizing radiation than monocentrics.

Multiple haploids, triploids, and tetraploids found in modern-day "living fossil" .

, the last extant representative of a lineage of Mesozoic gymnosperms, is one of the few seed plants with an exceptionally long (~300 Myr) evolutionary history free of genome-wide duplications (polyploidy). Despite this genome conservatism, we have recently found a viable spontaneous tetraploid sapling during routine screening of several plants, demonstrating that natural polyploidy is possible in . Here we provide a much wider flow cytometry survey of ploidy in some European collections, and own seedlings (>2200 individuals and ~200 cultivars).