Pollinator attraction in Anacamptis papilionacea (Orchidaceae): a food or a sex promise?

The Mediterranean orchid Anacamptis papilionacea , despite showing a typical food-deceptive floral display, has also been reported to frequently attract male pollinators, suggesting a potentiality for sexual attraction. In a survey from a southern Italian population of A. papilionacea and their hybrids with Anacamptis morio , we collected 37 pollinators belonging to five bee species carrying 126 orchid pollinia. The main pollinator of A. papilionacea was Anthophora crinipes male (48.6%), but the number of females was not negligible (22.9%). We also found pollinator sharing between the hybrid and the parental species. Our findings confirm that, contrary to other food-deceptive species, A. papilionacea mainly attracts male insects, but also that, in contrast to sexually deceptive species, this attraction is not specific. We suggest that A. papilionacea adopts a complex mix of food and sexually deceptive pollination and could represent a helpful model for studying the transition between different pollination strategies.     

An integrative approach to species delimitation in Benthomangelia (Mollusca: Conoidea)

DNA sequences are currently used to propose primary hypotheses of species delimitation, especially when morphological variability is difficult to assess. In an integrative taxonomy framework, these hypotheses are then compared with other characters, such as morphology or geography, to produce robust species delimitations. For this purpose, the cytochrome oxidase subunit I (COI) gene has been sequenced for almost 50 specimens of the genus Benthomangelia , a deep-sea marine gastropod genus, collected in the South-West Pacific. Five genetic groups, displaying low and high genetic distances respectively within and between groups, were defined. COI hypotheses were compared with both the results obtained with the independent nuclear 28S gene and with an elliptic Fourier analysis of the shape of the last whorl of the shell. 28S gene analysis confirmed the same well-supported groups as COI, and elliptic Fourier analysis identified several morphological characters that vary similarly to genetic variability.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 696–708.     

Relationship between floral tube length and nectar robbing in Duranta erecta L. (Verbenaceae)

Although nectar robbing is a common phenomenon in plant species with tubular flowers or flowers with nectar spurs, the potential effect of this illegitimate interaction on plant reproductive success has not received the deserved attention. In the present study, we analysed the functional relationship between flower morphology and nectar robbing, and examined the reproductive consequences of the interaction in a population of Duranta erecta (Verbenaceae) on the island of Cuba. The results show that nectar robbing is conducted by the carpenter bees Xylocopa cubaecola and affects up to 44% of flowers in the studied population. However, not all the flowers have the same probability of being robbed. The chance of flowers being robbed increases with flower length and flower diameter. Moreover, nectar robbing significantly decreases the chance that flowers will set fruit. Also, the impact of nectar robbing on the probability of flowers to set fruits is dependent on the plant. We suggest that nectar robbing may represent an opposite selective force that balances the selection for longer corollas often imposed by pollinators specializing in visiting tubular flowers. Such a relationship with nectar robbers would have obvious implications for the evolution of tubular or closed flowers. This preliminary finding deserves further research in light of the ecological and evolutionary consequences of nectar robbing in tubular flowers.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 96 , 392–398.     

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.     

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.