Phylogeographic analyses reveal distinct lineages of the liverworts Metzgeria furcata (L.) Dumort. and Metzgeria conjugata Lindb. (Metzgeriaceae) in Europe and North America

Seed plant genera often exhibit intercontinental disjunctions where different species are found on different continents. Many morphologically circumscribed bryophyte species exhibit similar disjunctions. We used nucleotide sequences from the plastid and nuclear genomes to test hypotheses of phylogeography within representatives of the genus Metzgeria: Metzgeria furcata, Metzgeria conjugata, and Metzgeria myriopoda. The first two species have sexual and asexual populations, exhibit disjunctions between North America and Europe, and have been split into separate species, numerous subspecies or varieties. The third species occurs in eastern North America but is not reported from Europe. Phylogenetic analyses resolved three distinct lineages within the morphologically defined species, M. furcata: one in North America, and two in Europe. Similarly, three morphologically cryptic clades of M. conjugata were resolved by the molecular data: northern North America, Europe, and south‐eastern North America. For both species, molecular divergence among taxa occurred in the absence of morphological change. In the case of M. myriopoda, all plants from eastern North America were both morphologically uniform and genetically homogeneous (although not identical). The present study provides significant insight into a plant group with complex taxonomy, and indicates that these liverwort taxa with wide distributions, extreme sex ratios, and continental disjunctions harbor cryptic lineages. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 98 , 745–756.     

Proceedings of the signature series symposium “cellular therapies for orthopaedics and musculoskeletal disease proven and unproven therapies—promise,facts and fantasy,” international society for cellular therapies,montreal, canada,may 2, 2018

The Signature Series Symposium “Cellular Therapies for Orthopaedics and Musculoskeletal Disease Proven and Unproven Therapies—Promise, Facts and Fantasy” was held as a pre-meeting of the 26^th International Society for Cellular Therapy (ISCT) annual congress in Montreal, Canada, May 2, 2018. This was the first ISCT program that was entirely dedicated to the advancement of cell-based therapies for musculoskeletal diseases. Cellular therapies in musculoskeletal medicine are a source of great promise and opportunity. They are also the source of public controversy, confusion and misinformation. Patients, clinicians, scientists, industry and government share a commitment to clear communication and responsible development of the field. Therefore, this symposium convened thought leaders from around the world in a forum designed to catalyze communication and collaboration to bring the greatest possible innovation and value to patients with musculoskeletal conditions.     

Characterisation of a variant of zucchini yellow fleck virus (ZYFV), a potyvirus causing a wilt disease of melons in Israel*

A flexuous filamentous virus 750 nm in length was isolated from field-grown melons (Cucumis melo L.) and squirting cucumber (Ecballium elaterium L.). Infection of melon seedlings of most commercial varieties resulted in a lethal wilting, but late infections gave dieback. The virus infected systemically all economically important cucurbit crops. Its coat protein consists of a single polypeptide, 34 500 D in size, encapsidating a single stranded RNA genome of 10.1 kb. Antiserum against the Italian zucchini yellow fleck virus (ZYFV) reacted specifically with the Israeli isolate in both ISEM and Western blot. The virus was aphid transmissible in a non-persistent manner. Based on host range, host reaction and serological data, it is suggested that the virus described is an Israeli variant of ZYFV.     

Biochemical and Ultrastructural Changes in Tetrahymena pyriformis During Starvation*

SYNOPSIS. Certain of the ultrastructural and biochemical changes occurring during the first 25 hr of starvation in Tetrahymena pyriformis were studied. Ultrastructurally, numerous profiles of degenerating mitochondria were seen in the early stages of starvation. The presence of oxidizable substrate such as glucose and acetate did not prevent this degeneration. Numerous large nucleoli were formed, many of which seemed to be passing into the cytoplasm as forming autophagic vacuoles. There was a transient increase in Oil Red O-positive bodies, presumably lipid (triglycerides). The extent and duration of this increase were pronounced in the presence of acetate. The lipid droplets appeared to arise within the cisternae of the endoplasmic reticulum. Lipid reserves were apparently utilized prior to carbohydrates, as the disappearance of lipid droplets preceded glycogen utilization, both in the presence of acetate and in the absence of exogenous substrate. A considerable loss of cellular protein also occurred. In cells from inorganic medium supplemented with glucose, glycogen occupied much of the cell, leaving only islands of cell organelles. Acid phosphatase was localized, ultrastructurally, mainly in autophagic vacuoles which contained mitochondria and other cell organelles, and in association with small, double-membraned structures which seemed to be sequestering small areas of cytoplasm. Such sequestered areas also appeared within larger autophagic vacuoles. Residual bodies containing concentric whorls of myelin-like membranes surrounding a more solid core accumulated during starvation. Acid phosphatase activity decreased in amount but not in specific activity. The specific activity of cathespin doubled or tripled, but there was little change in total enzyme.     

The Plasma Membrane of Myxosporidian Valve Cells: Freeze Fracture Data

Freeze fracturing of Myxosporidian spores reveals the occurrence of a continuous layer of transmembrane particles all over the surface area of the valve cells which form the spore envelope. These particles are densely packed all over the P face membrane. Due to their polygonal outline, their diameter (6-7 nm) and their central core, they resemble the particles forming the connections of gap junctions which metabolically couple the neighboring cells in animal tissues. In the present report, the role of the transmembrane particles is still hypothetical. However, they might represent a membrane structural specialization of the spores which are submitted to osmotic variations of the fluid external medium. Furthermore similar transmembrane particles are observed at the level of the septate junction which seals the valve cells. In this occurrence, they are arranged in a series of 40 double rows parallel to the suture of the spore envelope. These findings support the view that Myxosporidia are Metazoa and raise the problem of their origin.     

The two‐component histidine kinase Fhk1 controls stress adaptation and virulence of Fusarium oxysporum

Fungal histidine kinases (HKs) have been implicated in different processes, such as the osmostress response, hyphal development, sensitivity to fungicides and virulence. Members of HK class III are known to signal through the HOG mitogen‐activated protein kinase (MAPK), but possible interactions with other MAPKs have not been explored. In this study, we have characterized fhk1, encoding a putative class III HK from the soil‐borne vascular wilt pathogen Fusarium oxysporum. Inactivation of fhk1 resulted in resistance to phenylpyrrole and dicarboximide fungicides, as well as increased sensitivity to hyperosmotic stress and menadione‐induced oxidative stress. The osmosensitivity of Δfhk1 mutants was associated with a striking and previously unreported change in colony morphology. The Δfhk1 strains showed a significant decrease in virulence on tomato plants. Epistatic analysis between Fhk1 and the Fmk1 MAPK cascade indicated that Fhk1 does not function upstream of Fmk1, but that the two pathways may interact to control the response to menadione‐induced oxidative stress.     

MODELING THE EVOLUTION OF THE PERFORMANCE OF A SENSORY PANEL: A MIXED-MODEL AND CONTROL CHART APPROACH

A sensory panel is often used to profile the same type of product with the same set of attributes for many years. We are interested in characterizing the evolution of the performance of such a panel (and its panelists) over time. This article presents a methodology based on a mixed‐model approach that takes into account the evolution of both panel and panelist in the same model. At the panel level, linear and quadratic evolutions of the performance are tested. At the panelist level, the method allows detection of whether some panelists perform better than others, and whether this difference remains the same or evolves over time. This mixed‐model approach is followed by a graphical representation using a control chart method to identify occasional outliers. Data used to illustrate this methodology are eight sensory profiling data sets collected on ready‐made frozen meals between 1997 and 2001 (every 6 months). The performance index chosen as an example in this study is the individual repeatability measured by standard deviation over replicates.