Evolution and loss of long-fringed petals

Background: The Cucurbitaceae genus Trichosanthes comprises 90–100 species that occur from India to Japan and southeast to Australia and Fiji. Most species have large white or pale yellow petals with conspicuously fringed margins, the fringes sometimes several cm long. Pollination is usually by hawkmoths. Previous molecular data for a small number of species suggested that a monophyletic Trichosanthes might include the Asian genera Gymnopetalum (four species, lacking long petal fringes) and Hodgsonia (two species with petals fringed). Here we test these groups’ relationships using a species sampling of c. 60% and 4759 nucleotides of nuclear and plastid DNA. To infer the time and direction of the geographic expansion of the Trichosanthes clade we employ molecular clock dating and statistical biogeographic reconstruction, and we also address the gain or loss of petal fringes. Results: Trichosanthes is monophyletic as long as it includes Gymnopetalum, which itself is polyphyletic. The closest relative of Trichosanthes appears to be the sponge gourds, Luffa, while Hodgsonia is more distantly related. Of six morphology-based sections in Trichosanthes with more than one species, three are supported by the molecular results; two new sections appear warranted. Molecular dating and biogeographic analyses suggest an Oligocene origin of Trichosanthes in Eurasia or East Asia, followed by diversification and spread throughout the Malesian biogeographic region and into the Australian continent. Conclusions: Long-fringed corollas evolved independently in Hodgsonia and Trichosanthes, followed by two losses in the latter coincident with shifts to other pollinators but not with long-distance ispersal events. Together with the Caribbean Linnaeosicyos, the Madagascan Ampelosicyos and the tropical African Telfairia, these cucurbit lineages represent an ideal system for more detailed studies of the evolution and function of petal fringes in plant-pollinator mutualisms

New Classification of the Dictyostelids

Traditional morphology-based taxonomy of dictyostelids is rejected by molecular phylogeny. A new classification is presented based on monophyletic entities with consistent and strong molecular phylogenetic support and that are, as far as possible, morphologically recognizable. All newly named clades are diagnosed with small subunit ribosomal RNA (18S rRNA) sequence signatures plus morphological synapomorphies where possible. The two major molecular clades are given the rank of order, as Acytosteliales ord. nov. and Dictyosteliales. The two major clades within each of these orders are recognized and given the rank of family as, respectively, Acytosteliaceae and Cavenderiaceae fam. nov. in Acytosteliales, and Dictyosteliaceae and Raperosteliaceae fam. nov. in Dictyosteliales. Twelve genera are recognized: Cavenderia gen. nov. in Cavenderiaceae, Acytostelium, Rostrostelium gen. nov. and Heterostelium gen. nov. in Acytosteliaceae, Tieghemostelium gen. nov., Hagiwaraea gen. nov., Raperostelium gen. nov. and Speleostelium gen. nov. in Raperosteliaceae, and Dictyostelium and Polysphondylium in Dictyosteliaceae. The polycephalum complex is treated as Coremiostelium gen. nov. (not assigned to family) and the polycarpum complex as Synstelium gen. nov. (not assigned to order and family). Coenonia, which may not be a dictyostelid, is treated as a genus incertae sedis. Eighty-eight new combinations are made at species and variety level, and Dictyostelium ammophilum is validated

Profiling surface proteins on individual exosomes using a proximity barcoding assay

Exosomes have been implicated in numerous biological processes, and they may serve as important disease markers. Surface proteins on exosomes carry information about their tissues of origin. Because of the heterogeneity of exosomes it is desirable to investigate them individually, but this has so far remained impractical. Here, we demonstrate a proximity-dependent barcoding assay to profile surface proteins of individual exosomes using antibody-DNA conjugates and next-generation sequencing. We first validate the method using artificial streptavidin-oligonucleotide complexes, followed by analysis of the variable composition of surface proteins on individual exosomes, derived from human body fluids or cell culture media. Exosomes from different sources are characterized by the presence of specific combinations of surface proteins and their abundance, allowing exosomes to be separately quantified in mixed samples to serve as markers for tissue-specific engagement in disease

Allele-specific regulation of MTTP expression influences the risk of ischemic heart disease

Peer reviewe

Acacia fumosa sp. nov. (Fabaceae) from eastern Ethiopia

The new species Acacia fumosa is described and illustrated. It is confined to the Somali National Regional State (Ogaden) in eastern Ethiopia, where it is dominant and widespread on limestone hills in an area of at least 8 000 km2. Acacia fumosa is closely related to A. ochracea in south-western Somalia, but differs, for example, in its ash grey, smooth and non-flaking bark, densely pubescent leaves, and pink flowers

The names of Dipterygium glaucum and Rorida cornus-africani in Cleome (Cleomaceae), and on the identity of Forsskal & apos;s Bunias orientalis

Cleome pallida is the name to be used for Dipterygium glaucum, widespread in desert habitats of northeastern Africa and southwestern Asia, when this species is treated as a Cleome. A comprehensive synonymy is provided and all names are typified. The record of Bunias orientalis made by Forsskal in Yemen is shown to be based on misidentified material of C. pallida. The new combination C. cornus-africani is made for a species endemic to northeastern Somalia that was first described as a Rorida

The typification of Veronica peregrina (Plantaginaceae) reconsidered

Veronica peregrina Linnaeus (1753: 14) was described in the protologue as “Veronica floribus solitariis sessilibus, foliis lanceolato-linearibus glabris obtusis integerrimis, caule erecto”, a phrase-name that was quoted directly from his previous treatment in Flora suecica (Linnaeus 1745: 6). Linnaeus (1753) stated about the origin of the plant: “Habitat in Europae hortis, arvisque” and also cited one synonym: “Veronica terrestris annua, folio polygoni, flore albo. Moris. Hist. 2. p. 322, sect. 3. t. 24. f. 19” (Morison 1680), based on material from England

Vincetoxicum arabicum (Apocynaceae-Asclepiadoideae), a new combination for a species in Arabia and Africa, and notes on Rhinolobium

The new combination Vincetoxicum arabicum is made for a species in Saudi Arabia and northeastern and eastern Africa that has previously mostly been called Blyttia fruticulosa or Vincetoxicum fruticulosum. The basionym, Blyttia arabica, previously regarded as a superfluous name, is resurrected. A synonymy of V. arabicum is provided, and the species is illustrated by photographs. Rhinolobium, with R. tenue as type, published simultaneously with Blyttia and B. arabica, is an older name for Aspidoglossum

The Genus Boswellia (Burseraceae) : The Frankincense Trees

The history of frankincense, starting in ancient Egypt, and the frankincense trees, what is now the genus Boswellia Roxb., is briefly outlined. General remarks are given on phylogeny and dating of the genus, previous taxonomic treatments, authorship and etymology, chromosome number, cotyledons and hypocotyl, cliff-dwelling versus ground-dwelling species, bark, stipules, breeding system and pollination, fruits and dispersal, hybrids, chemistry and uses, conservation, and harvesting and processing of frankincense. According to previously published phylogenies, Boswellia is sister to the Asian genus Garuga Roxb., and the crown group dates back to the mid Miocene. Twenty-four species are recognized in Boswellia, distributed from Mali and Burkina Faso in the west to India in the east, and from Oman and north-central India in the north to northeastern Tanzania in the south. Most species are found in the Horn of Africa region, with the highest concentration (11 species) in the Socotra archipelago (Yemen). A key to the species of Boswellia is provided, as well as distribution maps, illustrations, descriptions, notes on etymology, distribution and habitat, vernacular names and uses, IUCN Red List assessments, taxonomic remarks, and lists of collections, for all species. Boswellia aspleniifolia (Balf.f.) Thulin, comb. nov., based on Odina aspleniifolia Balf.f., B. samhaensis Thulin & Scholte, sp. nov., and B. scopulorum Thulin, sp. nov., are published, all from the Socotra archipelago. The name Boswellia “hesperia” is provisionally proposed for an apparently new species from Socotra, of which only photographs have been available. Fifteen names are lectotypified, and a neotype is designated for B. papyrifera (Delile) Hochst

The Genus Boswellia (Burseraceae) : The Frankincense Trees

The history of frankincense, starting in ancient Egypt, and the frankincense trees, what is now the genus Boswellia Roxb., is briefly outlined. General remarks are given on phylogeny and dating of the genus, previous taxonomic treatments, authorship and etymology, chromosome number, cotyledons and hypocotyl, cliff-dwelling versus ground-dwelling species, bark, stipules, breeding system and pollination, fruits and dispersal, hybrids, chemistry and uses, conservation, and harvesting and processing of frankincense. According to previously published phylogenies, Boswellia is sister to the Asian genus Garuga Roxb., and the crown group dates back to the mid Miocene. Twenty-four species are recognized in Boswellia, distributed from Mali and Burkina Faso in the west to India in the east, and from Oman and north-central India in the north to northeastern Tanzania in the south. Most species are found in the Horn of Africa region, with the highest concentration (11 species) in the Socotra archipelago (Yemen). A key to the species of Boswellia is provided, as well as distribution maps, illustrations, descriptions, notes on etymology, distribution and habitat, vernacular names and uses, IUCN Red List assessments, taxonomic remarks, and lists of collections, for all species. Boswellia aspleniifolia (Balf.f.) Thulin, comb. nov., based on Odina aspleniifolia Balf.f., B. samhaensis Thulin & Scholte, sp. nov., and B. scopulorum Thulin, sp. nov., are published, all from the Socotra archipelago. The name Boswellia “hesperia” is provisionally proposed for an apparently new species from Socotra, of which only photographs have been available. Fifteen names are lectotypified, and a neotype is designated for B. papyrifera (Delile) Hochst